GOLUB CAPITAL BDC, Inc.

Note 1. Organization

Golub Capital BDC, Inc. (“GBDC” and, collectively with its consolidated subsidiaries, the “Company”) is an externally managed, closed-end, non-diversified management investment company. GBDC has elected to be regulated as a business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). In addition, for U.S. federal income tax purposes, GBDC has elected to be treated as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”).

The Company’s investment strategy is to invest primarily in one stop (a loan that combines characteristics of traditional first lien senior secured loans and second lien or subordinated loans and that are often referred to by other middle-market lenders as unitranche loans) and other senior secured loans of U.S. middle-market companies that are, in most cases, sponsored by private equity firms. The Company also selectively invests in second lien and subordinated (a loan that ranks senior only to a borrower’s equity securities and ranks junior to all of such borrower’s other indebtedness in priority of payment) loans of, and warrants and minority equity securities in, U.S. middle-market companies. The Company has entered into the Fifth Amended and Restated Investment Advisory Agreement effective as of June 3, 2024 (the “Investment Advisory Agreement” or “Post-GBDC 3 Merger Advisory Agreement”) with GC Advisors LLC (the “Investment Adviser”), under which the Investment Adviser manages the day-to-day operations of, and provides investment advisory services to, the Company. Under an administration agreement (the “Administration Agreement”) the Company is provided with certain services by an administrator (the “Administrator”), which is currently Golub Capital LLC.

On September 16, 2019, the Company completed its acquisition of Golub Capital Investment Corporation (“GCIC”), a Maryland corporation (the “GCIC Merger”), pursuant to that certain Agreement and Plan of Merger (as amended, the “GCIC Merger Agreement”), dated as of November 27, 2018, by and among the Company, GCIC, Fifth Ave Subsidiary Inc., a Maryland corporation and wholly owned subsidiary of the Company (“GCIC Merger Sub”), the Investment Adviser, and, for certain limited purposes, the Administrator.

On June 3, 2024, the Company completed its acquisition of Golub Capital BDC 3, Inc. (“GBDC 3”), a Maryland corporation (the “GBDC 3 Merger”), pursuant to that certain Agreement and Plan of Merger (as amended, the “GBDC 3 Merger Agreement”), dated as of January 16, 2024, by and among the Company, GBDC 3, Park Avenue Subsidiary Inc., a Maryland corporation and wholly owned subsidiary of the Company (“GBDC 3 Merger Sub”), the Investment Adviser, and, for certain limited purposes, the Administrator. Upon consummation of the GBDC 3 Merger, the Company entered into the Investment Advisory Agreement. The Investment Advisory Agreement replaced the Fourth Amended and Restated Investment Advisory Agreement by and between the Company and the Investment Adviser dated as of July 1, 2023 (the “Prior Investment Advisory Agreement”). Refer to Note 3 for more information on the Investment Advisory Agreement and the Prior Investment Advisory Agreement.

Note 2. Significant Accounting Policies and Recent Accounting Updates

Basis of presentation: The Company is an investment company as defined in the accounting and reporting guidance under Accounting Standards Codification (“ASC”) Topic 946 —Financial Services— Investment Companies (“ASC Topic 946”).

The accompanying consolidated financial statements of the Company and related financial information have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) as established by the Financial Accounting Standards Board (“FASB”) for financial information and pursuant to the requirements for reporting on Form 10-K and Regulation S-X. In the opinion of management, the consolidated financial statements reflect all adjustments and reclassifications consisting solely of normal accruals that are necessary for the fair presentation of financial results as of and for the periods presented. All intercompany balances and transactions have been eliminated. Certain prior period amounts have been reclassified to conform to the current period presentation.

Fair value of financial instruments: The Company applies fair value to all of its financial instruments in accordance with ASC Topic 820 —Fair Value Measurement(“ASC Topic 820”). ASC Topic 820 defines fair value, establishes a framework used to measure fair value and requires disclosures for fair value measurements. On August 2, 2024, the Company’s board of directors (the “Board”) designated the Investment Adviser as the Company’s valuation designee (“Valuation Designee”) in accordance with Rule 2a-5 under the 1940 Act. As of such date, the Valuation Designee is responsible for determining the fair value of the Company’s portfolio investments, subject to oversight of the Board. In accordance with ASC Topic 820, the Valuation Designee has categorized the Company’s financial instruments carried at fair value, based on the priority of the valuation technique, into a three-level fair value hierarchy. Fair value is a market-based measure considered from the perspective of the market participant who holds the financial instrument rather than an entity-specific measure. Therefore, when market assumptions are not readily available, the Investment Adviser’s own assumptions are set to reflect those that management believes market participants would use in pricing the financial instrument at the measurement date.

The availability of observable inputs can vary depending on the financial instrument and is affected by a wide variety of factors, including, for example, the type of product, whether the product is new, whether the product is traded on an active exchange or in the secondary market and the current market conditions. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Valuation Designee in determining fair value is greatest for financial instruments classified as Level 3.

Any changes to the valuation methodology are reviewed by management and the Board to confirm that the changes are appropriate. As markets change, new products develop and the pricing for products becomes more or less transparent, the Valuation Designee will continue to refine its valuation methodologies. See further description of fair value methodology in Note 6.

Use of estimates: The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Consolidation: As provided under Regulation S-X and ASC Topic 946, the Company will generally not consolidate its investment in a company other than an investment company subsidiary or a controlled operating company whose business consists of providing services to the Company. Accordingly, the Company consolidated the results of the Company’s wholly-owned subsidiaries listed in the table below in its consolidated financial statements:

1. Prior to April 22, 2025, the date of each entity’s dissolution.

2. Prior to November 18, 2024, the date of each entity’s dissolution.

3. GCIC CLO II Depositor LLC (“GCIC 2018 CLO Depositor”) was renamed to Golub Capital BDC CLO 8 Depositor LLC (“BDC CLO 8 Depositor”) effective November 18, 2024.

4. GCIC CLO II LLC (“GCIC 2018 Issuer”) was renamed to Golub Capital BDC CLO 8 LLC (“2024 Issuer”) effective November 18, 2024.

5. Prior to April 30, 2025, the date of each entity’s dissolution.

6. GBDC 3 Holdings Coinvest, Inc. merged into GBDC Holdings Coinvest, Inc. effective September 1, 2025.

7. Golub Capital BDC 3 CLO 2 LLC (“GBDC 3 2022-2 Issuer”) merged into GBDC 3 Funding LLC (“GBDC 3 Funding”) effective May 19, 2025.

8. Golub Capital BDC 3 ABS 2022-1 LLC (“GBDC 3 2022 Issuer”) merged into GBDC 3 Funding LLC (“GBDC 3 Funding”) effective August 21, 2025.

Assets related to transactions that do not meet ASC Topic 860 requirements for accounting sale treatment are reflected in the Company’s Consolidated Statements of Financial Condition as investments. Those assets are owned by special purpose entities, including BDC Holdings, Funding II, GCIC Holdings, GBDC 3 Holdings, GBDC 3 Funding, 2024 Issuer and, prior to November 18, 2024, GCIC 2018 Issuer, 2018 Issuer and GBDC 3 2021 Issuer,

GCIC Funding, (prior to April 30, 2025), GBDC 3 2022-2 Issuer (prior to May 19, 2025), and GBDC 3 2022 Issuer (prior to August 21, 2025) that are consolidated in the Company’s consolidated financial statements. The creditors of the special purpose entities have received security interests in such assets and such assets are not intended to be available to the creditors of GBDC (or any affiliate of GBDC).

Cash and cash equivalents and foreign currencies: Cash and cash equivalents and foreign currencies are highly liquid investments with an original maturity of three months or less at the date of acquisition. The Company deposits its cash in financial institutions and, at times, such balances exceed the Federal Deposit Insurance Corporation insurance limits.

Restricted cash and cash equivalents and restricted foreign currencies: Restricted cash and cash equivalents and restricted foreign currencies include amounts that are collected and are held by trustees who have been appointed as custodians of the assets securing certain of the Company’s financing transactions. Restricted cash and cash equivalents and restricted foreign currencies are held by the trustees for payment of interest expense and principal on the outstanding borrowings or reinvestment into new assets.

Foreign currency translation: The Company’s books and records are maintained in U.S. dollars. Any foreign currency amounts are translated into U.S. dollars. Non-U.S. dollar transactions during the year are valued at the prevailing spot rates on the applicable transaction date and the related assets and liabilities are revalued at the prevailing spot rates as of year-end.

Net assets and fair values are presented based on the applicable foreign exchange rates and fluctuations arising from the translation of assets and liabilities are included within the net change in unrealized appreciation (depreciation) on translation of assets and liabilities in foreign currencies on the Consolidated Statements of Operations.

Foreign security and currency transactions involve certain considerations and risks not typically associated with investing in U.S. companies. These risks include, but are not limited to, currency fluctuations and revaluations and future adverse political, social and economic developments, which could cause investments in foreign markets to be less liquid and prices more volatile than those of comparable U.S. companies or U.S. government securities.

Derivative instruments:

The Company follows the guidance in ASC Topic 815 -Derivatives and Hedging (“ASC Topic 815”), when accounting for derivative instruments.

Forward currency contracts: A forward currency contract is an obligation between two parties to purchase or sell a specific currency for an agreed-upon price at a future date. The Company utilized forward currency contracts to economically hedge the currency exposure associated with certain foreign-denominated investments. The use of forward currency contracts does not eliminate fluctuations in the price of the underlying securities the Company owns or intends to acquire but establishes a rate of exchange in advance. Fluctuations in the value of these contracts are measured by the difference in the exchange rates on the contract date and reporting date and are recorded as unrealized appreciation (depreciation) until the contracts are closed. When the contracts are closed, realized gains (losses) are recorded. Realized gains (losses) and unrealized appreciation (depreciation) on the forward currency contracts are included in the Consolidated Statements of Operations. Unrealized appreciation (depreciation) on forward currency contracts is recorded on the Consolidated Statements of Financial Condition as a component of “Net unrealized appreciation on derivatives” or “Net unrealized depreciation on derivatives” by counterparty on a net basis across all derivative instruments, not taking into account collateral posted, which is recorded separately, if applicable.

The primary risks associated with forward currency contracts include failure of the counterparty to meet the terms of the contract and the value of the foreign currency changing unfavorably. These risks can exceed the amounts reflected in the Consolidated Statements of Financial Condition.

Refer to Note 5 for more information regarding the forward currency contracts.

Interest rate swaps: The Company designated interest rate swaps as the hedging instrument in qualifying fair value hedge accounting relationships, and as a result, the change in fair value of the hedging instruments and hedged items are recorded in interest expense and recognized as components of “Interest and other debt financing expenses” in the

Company’s Consolidated Statements of Operations. The fair value of the interest rate swaps is recorded on the Consolidated Statements of Financial Condition as a component of “Net unrealized appreciation on derivatives” or “Net unrealized depreciation on derivatives” by counterparty on a net basis across all derivative instruments, not taking into account collateral posted which is recorded separately, if applicable.

Refer to Note 5 for more information regarding the interest rate swaps.

Revenue recognition:

Investments and related investment income: Interest income is accrued based upon the outstanding principal amount and contractual interest terms of debt investments.

Original issue discount, market discount or premium and certain loan origination or amendment fees that are deemed to be an adjustment to yield (“Loan Origination Fees”) are capitalized and the Company accretes or amortizes such amounts over the life of the loan as interest income (“Discount Amortization”). For the years ended September 30, 2025, 2024 and 2023, the Company received Loan Origination Fees that were capitalized of $24,982, $19,817 and $17,692, respectively. For the years ended September 30, 2025, 2024 and 2023, interest income included $26,329, $22,074 and $19,951, respectively, of Discount Amortization.

For investments with contractual payment-in-kind (“PIK”) interest, which represents contractual interest accrued and added to the principal balance that generally becomes due at maturity, the Company will not accrue PIK interest if the portfolio company valuation indicates that the PIK interest is not collectible. For the years ended September 30, 2025, 2024 and 2023, investment income included$52,323,$49,715 and$40,590, respectively, of PIK interest and the Company capitalized PIK interest of $55,390, $52,552 and $38,844, respectively, into the principal balance of certain debt investments.

In addition, the Company generates revenue in the form of amendment, structuring or due diligence fees, fees for providing managerial assistance, consulting fees, administrative agent fees, and prepayment premiums on loans. The Company records these fees that are not deemed to be an adjustment to yield as fee income when earned. For the years ended September 30, 2025, 2024 and 2023, fee income included $2,418, $606 and $79 from non-recurring prepayment premiums, respectively.

For the years ended September 30, 2025, 2024 and 2023, the Company received interest and fee income in cash, which excludes capitalized loan origination fees, in the amounts of $782,906,$626,622 and $496,114, respectively.

Dividend income on equity securities is recorded as dividend income on an accrual basis to the extent that such amounts are payable by the portfolio company and are expected to be collected. The Company has certain preferred equity securities in the portfolio that contain a PIK dividend provision that are accrued and recorded as income at the contractual rates, if deemed collectible. The accrued PIK and non-cash dividends are capitalized to the cost basis of the preferred equity security and are generally collected when redeemed by the issuer.

For the years ended September 30, 2025, 2024 and 2023, the Company recognized PIK and non-cash dividend income of $30,707, $21,263 and $14,901, respectively, which were capitalized into the cost basis of certain preferred equity investments. For the years ended September 30, 2025, 2024 and 2023, the Company received $6,436, $47 and $10, of cash payments of accrued and capitalized preferred dividends.

Dividend income on common equity securities is recorded on the record date for private portfolio companies or on the ex-dividend date for publicly traded portfolio companies. Each distribution received from limited liability company (“LLC”) and limited partnership (“LP”) investments is evaluated to determine if the distribution should be recorded as dividend income or a return of capital. Generally, the Company will not record distributions from equity investments in LLCs and LPs as dividend income unless there are sufficient accumulated tax-basis earnings and profits in the LLC or LP prior to the distribution. Distributions that are classified as a return of capital are recorded as a reduction in the cost basis of the investment.

For the years ended September 30, 2025, 2024 and 2023, the Company recorded dividend income received in cash of $1,940, $691 and $1,340, respectively, and return of capital distributions received in cash of $2,322, $1,622 and $373, respectively.

Investment transactions are accounted for on a trade-date basis. Realized gains or losses on investments are measured by the difference between the net proceeds from the disposition and the amortized cost basis of investment, without regard to unrealized gains or losses previously recognized. The Company reports current period changes in fair value of investments that are measured at fair value as a component of the Net change in unrealized appreciation (depreciation) on investment transactions in the Consolidated Statements of Operations.

Non-accrual investments: A loan can be left on accrual status while the Company is pursuing repayment of the loan. Management reviews all loans that become 90 days or more past due on principal and interest, or when there is reasonable doubt that principal or interest will be collected, for possible placement on non-accrual status. When a loan is placed on non-accrual status, unpaid interest credited to income is reversed. Additionally, any capitalized Loan Origination Fees are no longer accreted to interest income as of the date the loan is placed on non-accrual status. Interest payments received on non-accrual loans are recognized as income or applied to principal depending upon management’s judgment. Non-accrual loans are restored to accrual status when past due principal and interest is paid and, in management’s judgment, payments are likely to remain current. The total fair value of non-accrual loans was $27,321 and $93,204 as of September 30, 2025 and September 30, 2024, respectively.

Management reviews all preferred equity securities accruing contractual PIK dividend income to determine if there is reasonable doubt that amortized cost or capitalized PIK and non-cash dividend income will be collected for possible placement on non-accrual status. When a preferred equity security is placed on non-accrual status, the contractual PIK dividend provision is no longer accrued to dividend income as of the date the preferred equity security is placed on non-accrual status. As of September 30, 2025, there wasone preferred equity security on non-accrual status with a fair value of $0. There wereno preferred equity securities on non-accrual status as of September 30, 2024.

Asset Acquisition: Pursuant to the GCIC Merger Agreement, the GCIC Merger Sub was first merged with and into GCIC, with GCIC as the surviving company, and, immediately following this initial merger, GCIC was then merged with and into the Company, with the Company as the surviving company. Pursuant to the GBDC 3 Merger Agreement, the GBDC 3 Merger Sub was first merged with and into GBDC 3, with GBDC 3 as the surviving company and, immediately following this initial merger, GBDC 3 was then merged with and into the Company, with the Company as the surviving company. The GCIC Merger and the GBDC 3 Merger were accounted for under the asset acquisition method of accounting in accordance with ASC 805 —Business Combinations — Related Issues (“ASC Topic 805”), also referred to as “asset acquisition.” Under the asset acquisition method of accounting, acquiring assets in groups not only requires ascertaining the cost of the asset (or net assets), but also allocating that cost to the individual assets (or individual assets and liabilities) that make up the group. Per ASC Topic 805, assets are recognized based on their cost to the acquiring entity, which generally includes transaction costs of the asset acquisition, and no gain or loss is recognized unless the fair value of non-cash assets given as consideration differs from the assets carrying amounts on the acquiring entity’s books.

The cost of the group of assets acquired in an asset acquisition is allocated to the individual assets acquired or liabilities assumed based on the relative fair values of net identifiable assets acquired other than “non-qualifying” assets (for example cash) and does not give rise to goodwill. To the extent that the consideration paid to GCIC or GBDC 3’s stockholders exceeded the relative fair values of the net identifiable assets of GCIC or GBDC 3 acquired other than “non-qualifying” assets, any such premium paid by the Company was further allocated to the cost of the GCIC or GBDC 3 assets acquired by the Company pro-rata to their relative fair value, other than “non-qualifying” assets. As both GCIC and GBDC 3 did not have any “qualifying” assets at the time of acquisition, the premium was allocated to “non-qualifying” assets, which are GCIC and GBDC 3’s investments in loans and equity securities, including its investment in GCIC SLF. Immediately following the acquisitions of GCIC and GBDC 3, the Company recorded its assets at their respective fair values and, as a result, the purchase premium allocated to the cost basis of the GCIC and GBDC 3 assets acquired were immediately recognized as unrealized depreciation on the Company's Consolidated Statement of Operations. The purchase premium allocated to investments in loan securities will amortize over the life of the loans through interest income, with a corresponding reversal of the unrealized depreciation on the loans acquired from GCIC and GBDC 3 through their ultimate disposition. Amortization expense of purchase premium for the years ended September 30, 2025, 2024 and 2023 was $17,423, $11,671 and $7,073, respectively. The purchase premium allocated to investments in equity securities will not amortize over the life of the equity securities through interest income and, assuming no subsequent change to the fair value of the equity securities acquired from GCIC or GBDC 3 and disposition of such equity securities at fair value, the

Company will recognize a realized loss with a corresponding reversal of the unrealized depreciation upon disposition of the equity securities acquired from GCIC or GBDC 3.

Income taxes: The Company has elected to be treated as a RIC under Subchapter M of the Code and operates in a manner so as to qualify for the tax treatment applicable to RICs. In order to qualify and be subject to tax as a RIC, among other things, the Company is required to meet certain source of income and asset diversification requirements and timely distribute dividends for U.S. federal income tax purposes to its stockholders of an amount generally at least equal to 90% of investment company taxable income, as defined by the Code and determined without regard to any deduction for dividends paid, for each tax year. The Company has made, and intends to continue to make, the requisite distributions to its stockholders, which will generally relieve the Company from U.S. federal income taxes with respect to all income distributed to its stockholders.

Depending on the level of taxable income earned in a tax year, the Company can determine to retain taxable income in excess of current year dividend distributions and distribute such taxable income in the next tax year. The Company could then be required to incur a 4% excise tax on such income. To the extent that the Company determines that its estimated current year annual taxable income, determined on a calendar year basis, could exceed estimated current calendar year dividend distributions, the Company accrues excise tax, if any, on estimated excess taxable income as taxable income is earned. For the year ended September 30, 2025, the Company recorded a reversal of the accrual for U.S. federal excise tax expense of $475. For the years ended September 30, 2024 and 2023, $1,124 and $3,682, respectively, was recorded for U.S. federal excise tax.

The Company accounts for income taxes in conformity with ASC Topic 740 —Income Taxes (“ASC Topic 740”). ASC Topic 740 provides guidelines for how uncertain tax positions should be recognized, measured, presented and disclosed in the consolidated financial statements. ASC Topic 740 requires the evaluation of tax positions taken in the course of preparing the Company’s tax returns to determine whether the tax positions are “more-likely-than-not” to be sustained by the applicable tax authority. Tax benefits of positions not deemed to meet the more-likely-than-not threshold would be recorded as a tax expense or tax benefit in the current year. It is the Company’s policy to recognize accrued interest and penalties related to uncertain tax benefits in income tax expense. There were no material unrecognized tax benefits or unrecognized tax liabilities related to uncertain income tax positions through September 30, 2025. The Company’s tax returns for the 2022 through 2024 tax years remain subject to examination by U.S. federal and most state tax authorities.

Certain of the Company's consolidated subsidiaries are subject to U.S. federal and state corporate-level income taxes. Income tax expense, if any, is included under the income category for which it applies in the Consolidated Statements of Operations. For the year ended September 30, 2025, the Company didnot record any U.S. income tax expense. For the year ended September 30, 2024, $71 was recorded for U.S. income tax expense. For the year ended September 30, 2023, the Company didnot record any U.S. income tax expense.

Dividends and distributions: Dividends and distributions to common stockholders are recorded on the ex-dividend date. The amount to be paid out as a dividend or distribution is determined by the Board each quarter and is generally based upon the earnings estimated by management. Net realized capital gains, if any, are distributed at least annually, although the Company can retain such capital gains for investment in its discretion.

The Company has adopted a dividend reinvestment plan (“DRIP”) that provides for reinvestment of any distributions the Company declares in cash on behalf of its stockholders, unless a stockholder elects to receive cash. As a result, if the Board authorizes and the Company declares a cash distribution, then stockholders who participate in the DRIP will have their cash distribution reinvested in additional shares of the Company’s common stock, rather than receiving the cash distribution. The Company expects to use newly issued shares under the guidelines of the DRIP if the Company’s shares are trading at a premium to net asset value. The Company can purchase shares in the open market in connection with the obligations under the plan, and in particular, if the Company’s shares are trading at a significant discount to net asset value (“NAV”) and the Company is otherwise permitted under applicable law to purchase such shares, the Company intends to purchase shares in the open market in connection with any obligations under the DRIP.

In the event the market price per share of the Company’s common stock on the date of a distribution exceeds the most recently computed NAV per share of the common stock, the Company will issue shares of common stock to participants in the DRIP at the greater of the most recently computed NAV per share of common stock or 95% of the current market price per share of common stock (or such lesser discount to the current market price per share that still exceeds the most recently computed NAV per share of common stock).

Share repurchase plan: The Company has a share repurchase program (the “Program”) which allows the Company to repurchase the Company’s outstanding common stock on the open market at prices below the Company’s NAV as reported in its most recently published consolidated financial statements. The Board re-approved the Program in August 2025 and the Program is implemented at the discretion of management. Shares can be purchased from time to time at prevailing market prices, through open market transactions, including block transactions. The Program permits repurchases up to $150,000 of the Company's common stock. Refer to Note 13 for more information on the share repurchases under the Program.

Equity Distribution Agreement: On October 6, 2023, the Company entered into an equity distribution agreement, which was most recently amended on May 16, 2025, (the “2023 Equity Distribution Agreement”), by and among the Company, the Investment Adviser, the Administrator, and Keefe, Bruyette & Woods, Inc. and Regions Securities LLC (the “Placement Agents”), in connection with the sale by the Company of shares of its common stock, having an aggregate offering price of up to $288,043, in an “at the market offering,” in amounts and at times to be determined by the Company. Through September 30, 2025, the Company has issued 2,408,940 of shares of its common stock for net proceeds to the Company of $38,043 under the 2023 Equity Distribution Agreement. Actual sales, if any, will depend on a variety of factors to be determined by the Company from time to time, including, among others, market conditions and the market price of the Company’s common stock. The 2023 Equity Distribution Agreement provides that the Company can offer and sell shares of its common stock from time to time through, or to, the Placement Agents. Sales of the shares can be made in negotiated transactions or transactions that are deemed to be “at the market,” as defined in Rule 415 under the Securities Act of 1933, as amended, including sales made directly on The Nasdaq Global Select Market or any similar securities exchange or sales made to or through a market maker other than on a securities exchange, at prices related to the prevailing market prices or at negotiated prices. Pursuant to the terms of the 2023 Equity Distribution Agreement, the Placement Agents receive a commission from the Company of up to 1.50% of the gross sales price of any shares sold through the Placement Agents under the 2023 Equity Distribution Agreement. Offering costs for the 2023 Equity Distribution Agreement are charged against the proceeds from equity offerings when proceeds are received. During the year ended September 30, 2025, the Company issued 2,408,940 shares of common stock under the 2023 Equity Distribution Agreement. During the years ended September 30, 2024 and 2023, the Company didnot issue any shares of common stock under the 2023 Equity Distribution Agreements.

Deferred debt issuance costs: Deferred debt issuance costs represent fees and other direct incremental costs incurred in connection with the Company’s borrowings. As of September 30, 2025 and September 30, 2024, the Company had deferred debt issuance costs of $26,005 and $25,361, respectively.

These amounts are amortized and included in interest expense and other debt financing expenses in the Consolidated Statements of Operations over the estimated average life of the borrowings. Amortization expense for deferred debt issuance costs for the years ended September 30, 2025, 2024 and 2023 was $9,995, $9,237 and $7,380, respectively.

Deferred offering costs: Deferred offering costs consist of fees paid in relation to legal, accounting, regulatory and printing work completed in preparation of equity offerings. Deferred offering costs are charged against the proceeds from equity offerings when received. These amounts are included in other assets on the Consolidated Statements of Financial Condition.

Segment reporting: In accordance with ASC Topic 280 -Segment Reporting (“ASC Topic 280”), the Company has determined that it has a single operating and reporting segment. As a result, the Company’s segment accounting policies are the same as described herein and the Company does not have any intra-segment sales and transfers of assets.

The Company operates through a single operating and reporting segment with an investment objective to generate both current income and, to a lesser extent, capital appreciation through debt and equity investments. The chief operating decision maker (the “CODM”) is comprised of the senior executive committee that, as of September 30, 2025, includes the Company’s chief executive officer and chief financial officer and assesses the performance and makes operating decisions of the Company on a consolidated basis primarily based on the Company’s net increase (decrease) in net assets resulting from operations (“net income”). In addition to numerous other factors and metrics, the CODM utilizes net income as a key metric in evaluating the Company’s distribution policy. Performance metrics are provided to the CODM on a quarterly basis and are utilized to evaluate performance generated from segment net assets. As the Company’s operations comprise of a single reporting segment, the segment assets are reflected on the accompanying consolidated balance sheet as “total assets” and the significant segment expenses are listed on the accompanying consolidated statement of operations. The Company has elected to early adopt ASC Topic 280 as of March 31, 2025.

Recent Accounting Updates: In December 2023, the FASB issued Accounting Standards Update (“ASU”) No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU No. 2023-09 requires additional disaggregated disclosures on the entity’s effective tax rate reconciliation and additional details on income taxes paid. ASU No. 2023-09 is effective on a prospective basis, with the option for retrospective application, for annual periods beginning after December 15, 2024 and early adoption is permitted. The Company is currently evaluating the impact of adopting ASU No. 2023-09.

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40). ASU No. 2024-03 requires disaggregated disclosure of certain costs and expenses, including purchase of inventory, employee compensation, depreciation, amortization and depletion, within relevant income statement captions. ASU 2024-03 is effective for annual years beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption and retrospective application are permitted. The Company is currently evaluating the impact of adopting ASU No. 2024-03.

Note 3. Related Party Transactions

Investment Advisory Agreement: Under the Investment Advisory Agreement, the Investment Adviser manages the day-to-day operations of, and provides investment advisory services to, GBDC. The Board most recently re-approved the Investment Advisory Agreement in May 2025. The Investment Advisory Agreement amended the Prior Investment Advisory Agreement in order to incorporate changes to the calculation of the incentive fee rates and the incentive fee cap. Under the Investment Advisory Agreement, the incentive fee rates were reduced from 20.0% to 15.0%, and the incentive fee cap was reduced from 20.0% to 15.0%. None of the other material terms changed in the Investment Advisory Agreement as compared to the Prior Investment Advisory Agreement, including the services to be provided and the calculation of the base management fee. The Investment Advisory Agreement was entered into and effective as of June 3, 2024, the closing of the GBDC 3 Merger. On August 3, 2023, the Board approved, and the Company entered into, the Prior Investment Advisory Agreement with the Investment Adviser, effective as of July 1, 2023, pursuant to which the base management fee rate was reduced from 1.375% to 1.0%. The Investment Adviser is a registered investment adviser with the U.S. Securities and Exchange Commission (the “SEC”). The Investment Adviser receives fees for providing services, consisting oftwo components, a base management fee and an Incentive Fee (as defined below).

The base management fee is calculated at an annual rate equal to 1.0% (or 1.375% for periods ending on or before June 30, 2023) of the fair value of the average adjusted gross assets of the Company at the end of the two most recently completed calendar quarters (including assets purchased with borrowed funds and securitization-related assets, leverage, unrealized depreciation or appreciation on derivative instruments and cash collateral on deposit for such derivative instruments with custodian but adjusted to exclude cash and cash equivalents so that investors do not pay the base management fee on such assets) and is payable quarterly in arrears. Additionally, the Investment Adviser voluntarily excludes any assets funded with secured borrowing proceeds from the base management fee calculation. The base management fee is adjusted, based on the actual number of days elapsed relative to the total number of days in such calendar quarter, for any share issuances or repurchases during such calendar quarter. For purposes of the Investment Advisory Agreement, cash equivalents mean U.S. government securities and commercial paper instruments maturing within 270 days of purchase (which is different than the GAAP definition, which defines cash equivalents as U.S. government securities and commercial paper instruments maturing within 90 days of purchase). To the extent that the Investment Adviser or any of its affiliates provides investment advisory, collateral management or other similar services to a subsidiary of the Company, the base management fee will be reduced by an amount equal to the product of (1) the total fees paid to the Investment Adviser by such subsidiary for such services and (2) the percentage of such subsidiary’s total equity, including membership interests and any class of notes not exclusively held by one or more third parties, that is owned, directly or indirectly, by the Company.

The Investment Adviser served as collateral manager under the 2018 Collateral Management Agreement (as described in Note 7), the GCIC 2018 Collateral Management Agreement (as described in Note 7), the 2021 Collateral Management Agreement (as described in Note 7), the 2022 Collateral Management Agreement (as described in Note 7), and the 2022-2 Collateral Management Agreement (as described in Note 7), prior to their redemption, and serves as the collateral manager under the 2024 Collateral Management Agreement (as described in Note 7). Fees payable to the Investment Adviser for providing these services are offset against the base management fee payable by the Company under the Investment Advisory Agreement.

The base management fee incurred for the years ended September 30, 2025, 2024 and 2023 was $87,891, $62,514, and $70,802, respectively.

The Company has structured the calculation of the Incentive Fee to include a fee limitation such that an Incentive Fee for any quarter can only be paid to the Investment Adviser if, after such payment, the cumulative Incentive Fees paid to the Investment Adviser, calculated on a per share basis, since April 13, 2010, the effective date of the Company’s election to become a BDC, would be less than or equal to 15.0% of the Company’s Cumulative Pre-Incentive Fee Net Income Per Share (as defined below).

The Company accomplishes this limitation by subjecting each quarterly Incentive Fee payable under the Income and Capital Gain Incentive Fee Calculation (as defined below) to a cap (the “Incentive Fee Cap”). Under the Investment Advisory Agreement, the Incentive Fee Cap in any quarter is equal to the difference between (a)15.0% of Cumulative Pre-Incentive Fee Net Income Per Share (as defined below) and (b) Cumulative Incentive Fees Paid Per Share (as defined below). To the extent the Incentive Fee Cap is zero or a negative value in any quarter, no Incentive Fee would be payable in that quarter. If, for any relevant period, the Incentive Fee Cap calculation results in the Company paying less than the amount of the Incentive Fee calculated above, then the difference between the Incentive Fee and the Incentive Fee Cap will not be paid by GBDC and will not be received by the Investment Adviser as an Incentive Fee either at the end of such relevant period or at the end of any future period. “Cumulative Pre-Incentive Fee Net Income Per Share” equals the sum of “Pre-Incentive Fee Net Income Per Share” (as defined below) for each quarterly period since April 13, 2010. “Pre-Incentive Fee Net Income Per Share” equals the sum of (i) Pre-Incentive Fee Net Investment Income (as defined below) and (ii) Adjusted Capital Returns for the applicable period, divided by (b) the weighted average number of shares of GBDC common stock outstanding during such period. “Adjusted Capital Returns” for any period is the sum of the realized aggregate capital gains, realized aggregate capital losses, aggregate unrealized capital depreciation and aggregate unrealized capital appreciation for such period; provided that the calculation of realized aggregate capital gains, realized aggregate capital losses, aggregate unrealized capital depreciation and aggregate unrealized capital appreciation shall not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation resulting solely from the asset acquisition for any premium or discount paid for the acquisition of assets in a merger. “Cumulative Incentive Fees Paid Per Share” is equal to the sum of Incentive Fees Paid Per Share since April 13, 2010. “Incentive Fees Paid Per Share” for any period is equal to the Incentive Fees accrued and/or payable to the Company for such period, divided by the weighted average number of shares of common stock of GBDC during such period.

“Pre-Incentive Fee Net Investment Income” means interest income, dividend income and any other income (including any other fees such as commitment, origination, structuring, diligence and consulting fees or other fees that the Company receives from portfolio companies but excluding fees for providing managerial assistance) accrued during the calendar quarter, minus operating expenses for the calendar quarter (including the base management fee, taxes, any expenses payable under the Investment Advisory Agreement and the Administration Agreement, any expenses of securitizations and any interest expense and dividends paid on any outstanding preferred stock, but excluding the Incentive Fee). Pre-Incentive Fee Net Investment Income includes, in the case of investments with a deferred interest feature such as market discount, debt instruments with PIK interest, preferred stock with PIK dividends and zero coupon securities, accrued income that the Company has not yet received in cash.

Incentive Fees are calculated and payable quarterly in arrears (or, upon termination of the Investment Advisory Agreement, as of the termination date).

The income and capital gains incentive fee calculation (the “Income and Capital Gain Incentive Fee Calculation”) has two parts, the income component (the “Income Incentive Fee”) and the capital gains component (the “Capital Gain Incentive Fee” and, together with the Income Incentive Fee, the “Incentive Fee”). The Income Incentive Fee is calculated quarterly in arrears based on the Company’s Pre-Incentive Fee Net Investment Income for the immediately preceding calendar quarter.

For the years ended September 30, 2025, 2024 and 2023, the Income Incentive Fee incurred was $73,282, $77,163 and $74,066, respectively.

On January 16, 2024, the Investment Adviser agreed to irrevocably waive any incentive fees payable under the Prior Investment Advisory Agreement in excess of 15% and waive incentive fees in excess of an incentive fee cap that was also reduced to 15%, in each case effective as of January 1, 2024, for periods ending on or prior to the earlier of (i) the closing of the acquisition of GBDC 3 pursuant to the GBDC 3 Merger Agreement or (ii) the termination of the GBDC 3 Merger Agreement (the “Waiver Period”), in accordance with the terms of a waiver letter agreement (the “GBDC 3 Merger Waiver”) to the Prior Investment Advisory Agreement. During the Waiver Period, as a result of the GBDC 3 Merger Waiver, fees that were payable to the Investment Adviser under the Prior Investment Advisory Agreement, net of the GBDC 3 Merger Waiver, equaled those that were payable under the Post-GBDC 3 Merger Advisory Agreement. During the year ended September 30, 2024, the Investment Adviser irrevocably waived $5,157 of income incentive fees under the GBDC 3 Merger Waiver.

In addition, the Investment Adviser unilaterally agreed to irrevocably waive 100% of the Income Incentive Fee payable to the Investment Adviser under the Investment Advisory Agreement for the three months ended June 30, 2024 and $7,767 for the three months ended September 30, 2024.

For the year ended September 30, 2024, the Investment Adviser irrevocably waived income incentive fees, including the GBDC 3 Merger Waiver, of $27,324.

The Investment Advisory Agreement excludes the impact of asset acquisition resulting from a merger, including each of the GCIC Merger and GBDC 3 Merger, from the calculation of income subject to the Income Incentive Fee and the calculation of the Incentive Fee Cap. As a result, under the Investment Advisory Agreement, Pre-Incentive Fee Net Investment Income does not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation or any amortization or accretion of any purchase premium or discount to interest income solely from the asset acquisition for any premium or discount paid for the acquisition of assets in a merger, such as the premium to net asset value paid for the shares of GCIC and GBDC 3 common stock in the GCIC Merger and GBDC 3 Merger. Because of the structure of the Income Incentive Fee, it is possible that an Incentive Fee is calculated under this formula with respect to a period in which the Company has incurred a loss. For example, if the Company receives Pre-Incentive Fee Net Investment Income in excess of the hurdle rate (as defined below) for a calendar quarter, the Income Incentive Fee will result in a positive value and an Incentive Fee will be paid even if the Company has incurred a loss in such period due to realized and/or unrealized capital losses unless the payment of such Incentive Fee would cause the Company to pay Incentive Fees on a cumulative basis that exceed the Incentive Fee Cap.

Pre-Incentive Fee Net Investment Income, expressed as a rate of return on the value of the Company’s net assets (defined as total assets less indebtedness and before taking into account any Incentive Fees payable during the period) at the end of the immediately preceding calendar quarter, is compared to a fixed “hurdle rate” of 2.0% quarterly.

If market interest rates rise, it is possible that the Company will be able to invest funds in debt instruments that provide for a higher return, which would increase Pre-Incentive Fee Net Investment Income and make it easier for the Investment Adviser to surpass the fixed hurdle rate and receive an Incentive Fee based on such net investment income.

The Company’s Pre-Incentive Fee Net Investment Income used to calculate this part of the Incentive Fee is also included in the amount of the Company’s total assets (excluding cash and cash equivalents but including assets purchased with borrowed funds and securitization-related assets, unrealized depreciation or appreciation on derivative instruments and cash collateral on deposit with custodian) used to calculate the base management fee annual rate.

For periods ended on or before March 31, 2024, the Company calculated the Income Incentive Fee with respect to its Pre-Incentive Fee Net Investment Income quarterly, in arrears, as follows:

•Zero in any calendar quarter in which the Pre-Incentive Fee Net Investment Income did not exceed the hurdle rate;

•100% of the Company’s Pre-Incentive Fee Net Investment Income with respect to that portion of such Pre-Incentive Fee Net Investment Income, if any, that exceeds the hurdle rate but is less than 2.5% in any calendar quarter. This portion of the Company’s Pre-Incentive Fee Net Investment Income (which exceeds the hurdle rate but is less than 2.5%) is referred to as the “catch-up” provision. The catch-up is meant to provide the Investment Adviser with 20.0% of the Pre-Incentive Fee Net Investment Income as if a hurdle rate did not apply if the Company’s Pre-Incentive Fee Net Investment Income exceeds 2.5% in any calendar quarter; and

20.0% of the amount of the Company’s Pre-Incentive Fee Net Investment Income, if any, that exceeds 2.5% in any calendar quarter.

For periods ended after June 3, 2024, commencing with the three months ended June 30, 2024, the Company calculated the Income Incentive Fee with respect to its Pre-Incentive Fee Net Investment Income quarterly, in arrears, as follows:

•Zero in any calendar quarter in which the Pre-Incentive Fee Net Investment Income does not exceed the hurdle rate;

•100% of the Company’s Pre-Incentive Fee Net Investment Income with respect to that portion of such Pre-Incentive Fee Net Investment Income, if any, that exceeds the hurdle rate but is less than the percentage at which amounts payable to the Adviser equals 15.0% of the Company's Pre-Incentive Fee Net Investment Income as if a hurdle rate did not apply. This portion of the Company’s Pre-Incentive Fee Net Investment Income is referred to as the “catch-up” provision. The catch-up is meant to provide the Investment Adviser with 15.0% of the Pre-Incentive Fee Net Investment Income as if a hurdle rate did not apply; and

•15.0% of the amount of the Company’s Pre-Incentive Fee Net Investment Income, if any, that exceeds the catch-up provision in any calendar quarter.

The Capital Gain Incentive Fee equals (a)15.0% of the Company’s Capital Gain Incentive Fee Base (as defined below), if any, calculated in arrears as of the end of each calendar year (or upon termination of the Investment Advisory Agreement, as of the termination date), which commenced with the calendar year ending December 31, 2010, less (b) the aggregate amount of any previously paid Capital Gain Incentive Fees. The Company’s “Capital Gain Incentive Fee Base” equals (1) the sum of (A) realized capital gains, if any, on a cumulative positive basis from the date the Company elected to become a BDC through the end of each calendar year, (B) all realized capital losses on a cumulative basis and (C) all unrealized capital depreciation on a cumulative basis less (2) all unamortized deferred debt issuance costs, if and to the extent such costs exceed all unrealized capital appreciation on a cumulative basis.

•The cumulative aggregate realized capital losses are calculated as the sum of the amounts by which (a) the net sales price of each investment in the Company’s portfolio when sold is less than (b) the accreted or amortized cost basis of such investment.

•The cumulative aggregate realized capital gains are calculated as the sum of the differences, if positive, between (a) the net sales price of each investment in the Company’s portfolio when sold and (b) the accreted or amortized cost basis of such investment.

•The aggregate unrealized capital depreciation is calculated as the sum of the differences, if negative, between (a) the valuation of each investment in the Company’s portfolio as of the applicable Capital Gain Incentive Fee calculation date and (b) the accreted or amortized cost basis of such investment.

Realized capital gains and losses include gains and losses on investments, foreign currencies, including gains and losses on borrowings in foreign currencies, derivative contracts and any income tax related to cumulative aggregate realized gains and losses.

For the years ended September 30, 2025, 2024 and 2023, the Company didnot accrue a Capital Gain Incentive Fee. As of September 30, 2025 and September 30, 2024, there wasno Capital Gain Incentive Fee payable as calculated under the Investment Advisory Agreement as described above. Any payment due for a Capital Gain Incentive Fee under the terms of the Investment Advisory Agreement is calculated in arrears at the end of each calendar year.

In accordance with GAAP, the Company also is required to include the aggregate unrealized capital appreciation on investments in the calculation and accrue a capital gain incentive fee on a quarterly basis as if such unrealized capital appreciation were realized, even though such unrealized capital appreciation is not permitted to be considered in calculating the fee actually payable under the Investment Advisory Agreement, as applicable. If the Capital Gain Incentive Fee Base, adjusted as required by GAAP to include unrealized capital appreciation, is positive at the end of a period, then GAAP requires the Company to accrue a capital gain incentive fee equal to 15% of such amount, less the aggregate amount of the actual Capital Gain Incentive Fees paid and capital gain incentive fees accrued under GAAP in all prior periods. If such amount is negative, then there is no accrual for such period. The resulting accrual under GAAP in a given period results in additional expense if such cumulative amount is greater than in the prior period or a reversal of previously recorded expense if such cumulative amount is less than in the prior period. There can be no assurance that such unrealized capital appreciation will be realized in the future. For the years ended September 30, 2025, 2024 and 2023, the Company didnot accrue a capital gain incentive fee under GAAP. Changes in the accrual for the capital gain incentive fee under GAAP are included in incentive fee in the Consolidated Statements of Operations. As of September 30, 2025 and September 30, 2024, there wasno cumulative accrual of capital gain incentive fees under GAAP included in accounts payable and other liabilities on the Consolidated Statements of Financial Condition.

Administration Agreement: Under the Administration Agreement, the Administrator furnishes the Company with office facilities and equipment, provides the Company with clerical, bookkeeping and record keeping services at such facilities and provides the Company with other administrative services as the Administrator, subject to review by the Board, determines necessary to conduct the Company’s day-to-day operations. The Company reimburses the Administrator the allocable portion of overhead and other expenses incurred by it in performing its obligations under the Administration Agreement, including rent, fees and expenses associated with performing compliance functions and the Company’s allocable portion of the cost of its chief financial officer and chief compliance officer and their respective staffs. The Board reviews such expenses to determine that these expenses, including any allocation of expenses among the Company and other entities for which the Administrator provides similar services, are reasonable and comparable to administrative services charged by unaffiliated third-party asset managers. Under the Administration Agreement, the Administrator also provides, on the Company’s behalf, managerial assistance to those portfolio companies to which the Company is required to provide such assistance and will be paid an additional amount based on the cost of the services provided, which amount shall not exceed the amount the Company receives from such portfolio companies.

Included in accounts payable and other liabilities is $3,022 and $2,840 as of September 30, 2025 and September 30, 2024, respectively, for accrued allocated shared services under the Administration Agreement.

Other related party transactions: The Administrator pays for certain unaffiliated third-party expenses incurred by the Company. Such expenses include postage, printing, office supplies, rating agency fees and professional fees. These expenses are not marked-up and represent the same amount the Company would have paid had the Company paid the expenses directly. These expenses are subsequently reimbursed in cash.

Total expenses reimbursed to the Administrator during the years ended September 30, 2025, 2024 and 2023 were $8,347, $12,959 and $8,158, respectively.

As of September 30, 2025 and September 30, 2024, included in accounts payable and other liabilities were $2,527 and $2,658, respectively, for expenses paid on behalf of the Company by the Administrator.

The Company is party to an unsecured revolving credit facility with the Investment Adviser (as amended, the “Adviser Revolver”) which, as of September 30, 2025 permits the Company to borrow a maximum of $300,000 and expires on June 13, 2032. As of September 30, 2024, the Company was permitted to borrow a maximum of $200,000 under the Adviser Revolver. Refer to Note 7 for discussion of the Adviser Revolver.

Effective June 3, 2024, the Company assumed, as a result of the GBDC 3 Merger, an unsecured revolving credit facility with the Investment Adviser (“GBDC 3 Adviser Revolver”) that had a credit limit of $100,000. The GBDC 3 Adviser Revolver was terminated on June 11, 2024.

On June 3, 2024, the Company completed its acquisition of GBDC 3. Refer to Note 15 for more information regarding the GBDC 3 Merger.

Note 4. Investments

Investments as of September 30, 2025 and September 30, 2024 consisted of the following:

The following tables show the portfolio composition by geographic region at amortized cost and fair value as a percentage of total investments in portfolio companies. The geographic composition is determined by the location of the corporate headquarters of the portfolio company, which is not always indicative of the primary source of the portfolio company’s business.

• Represents an amount less than 0.1%

The industry compositions of the portfolio at amortized cost and fair value as a percentage of total investments in portfolio companies as of September 30, 2025 and September 30, 2024 were as follows:

• Represents an amount less than 0.1%.

• Represents an amount less than 0.1%.

Note 5. Derivatives

The Company enters into derivatives from time to time to help mitigate its foreign currency and interest rate risk exposures.

Forward Currency Contracts

The outstanding forward currency contracts as of September 30, 2025 and September 30, 2024 were as follows:

The impact of forward currency contracts not designated as an effective hedge accounting relationship for the years ended September 30, 2025, 2024 and 2023 on the Consolidated Statements of Operations, including realized and unrealized gains (losses) is summarized in the table below:

The following table is a summary of the average outstanding daily volume for forward currency contracts for the years ended September 30, 2025, 2024 and 2023:

Interest Rate Swaps

In connection with the 2028 Notes and 2029 Notes (each as defined in Note 7), the Company entered into interest rate swap agreements to more closely align the interest rate of such liability with its investment portfolio, which consists primarily of floating rate loans. The Company designated these interest rate swaps and the 2028 and 2029 Notes as a qualifying fair value hedge accounting relationship. See Note 7 for more information on the 2028 and 2029 Notes. As of September 30, 2025, the counterparties to the Company’s interest rate swap agreements were SMBC Capital Markets, Inc. and Macquarie Bank Limited. The outstanding interest rate swaps as of September 30, 2025 and September 30, 2024 were as follows:

As a result of the Company’s designation as a hedging instrument in a qualifying fair value hedge accounting relationship, the Company is required to fair value the hedging instrument and the related hedged item, with the changes in the fair value of each being recorded in interest and other debt financing expenses. The net unrealized gain/(loss) related to the fair value hedge was ($4,557) and $4,598, respectively, for theyears ended September 30, 2025 and September 30, 2024, respectively. The net unrealized gain /(loss) related to the fair value hedge is included in “Interest and other debt financing expenses” in the Company’s Consolidated Statement of Operations. The table below presents the components of the net unrealized gain /(loss) related to the fair value hedge recognized for the hedging instrument, the interest rate swaps, and the hedged items, the 2028 and 2029 Notes, from derivatives designated in a qualifying hedge accounting relationship for the years ended September 30, 2025 and 2024.

The table below presents the carrying value of the 2028 and 2029 Notes as of September 30, 2025 and September 30, 2024 that are designated in qualifying hedging relationships and the related cumulative hedging adjustment (increase/(decrease)) from the current hedging relationships included in such carrying value:

Offsetting Derivatives

In order to better define its contractual rights and to secure rights that will help the Company mitigate its counterparty risk, the Company has entered into an International Swaps and Derivatives Association, Inc. Master Agreement (“ISDA Master Agreement”) with each of its derivative counterparties, Macquarie Bank Limited (“Macquarie”) and SMBC Capital Markets, Inc. (“SMBC” and, together with Macquarie, the “Counterparties” and each a “Counterparty”). Each ISDA Master Agreement is a bilateral agreement between the Company and each Counterparty that governs over the counter (“OTC”) derivatives, including forward currency contracts and interest rate swaps, and contains, among other things, collateral posting terms and netting provisions in the event of a default and/or termination event. The provisions of each ISDA Master Agreements with each of the Counterparties permits a single net payment in the event of a default (close-out netting) or similar event, including the bankruptcy or insolvency of the counterparty.

For financial reporting purposes, cash collateral that has been pledged to cover obligations of the Company and cash collateral received from either Counterparty, if any, is included in the Consolidated Statements of Financial Condition as other assets or other accounts payable and other liabilities. As of September 30, 2025 and September 30, 2024, there was $4,890 and $650, respectively, of collateral pledged for derivatives which is included in other assets on the Consolidated Statements of Financial Condition. The Company minimizes counterparty credit risk by only entering into agreements with counterparties that it believes to be of good standing and by monitoring the financial stability of those counterparties.

The following table is intended to provide additional information about the effect of the offsetting derivative contracts on the consolidated financial statements of the Company including: the location of those fair values on the Consolidated Statements of Financial Condition, and the Company’s gross and net amount of assets and liabilities available for offset under netting arrangements as well as any related collateral received or pledged by the Company as of September 30, 2025 and September 30, 2024.

(1)The actual collateral pledged could be more than the amount shown due to over collateralization.

(2)Represents the net amount due from/(to) counterparties in the event of default.

Exclusion of the Investment Adviser from Commodity Pool Operator Definition

Engaging in commodity interest transactions such as swap transactions or futures contracts for the Company could cause the Investment Adviser to fall within the definition of “commodity pool operator” under the Commodity Exchange Act (the “CEA”) and related Commodity Futures Trading Commission (the “CFTC”) regulations. The Investment Adviser has claimed an exclusion from the definition of the term “commodity pool operator” under the CEA and the CFTC regulations in connection with its management of the Company and, therefore, is not subject to CFTC registration or regulation under the CEA as a commodity pool operator with respect to its management of the Company.

Note 6. Fair Value Measurements

The Company follows ASC Topic 820 for measuring fair value. Fair value is the price that would be received in the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Where available, fair value is based on observable market prices or parameters, or derived from such prices or parameters. Where observable prices or inputs are not available, valuation models are applied. These valuation models involve some level of estimation and judgment, the degree of which is dependent on the price transparency for the assets or liabilities or market and the assets’ or liabilities’ complexity. Effective August 2, 2024, the Board designated the Investment Adviser as the Company’s Valuation Designee in accordance with Rule 2a-5 under the 1940 Act. The Company’s fair value analysis, currently undertaken by the Valuation Designee, includes an analysis of the value of any unfunded loan commitments. Assets and liabilities are categorized for disclosure purposes based upon the level of judgment associated with the inputs used to measure their value. The valuation hierarchical levels are based upon the transparency of the inputs to the valuation of the asset or liability as of the measurement date. The three levels are defined as follows:

Level 1: Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2: Inputs include quoted prices for similar assets or liabilities in active markets and inputs that are observable for the assets or liabilities, either directly or indirectly, for substantially the full term of the assets or liabilities.

Level 3: Inputs include significant unobservable inputs for the assets or liabilities and include situations where there is little, if any, market activity for the assets or liabilities. The inputs into the determination of fair value are based upon the best information available and require significant management judgment or estimation.

In certain cases, the inputs used to measure fair value fall into different levels of the fair value hierarchy. In such cases, an asset’s or a liability’s categorization within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Currently, the Valuation Designee assesses the levels of assets and liabilities at each measurement date, and transfers between levels are recognized on the actual date of the event or change in circumstances that caused the transfers. There were no transfers among Level 1, 2 and 3 of the fair value hierarchy for assets and liabilities during the years ended September 30, 2025 and 2024. The following section describes the valuation techniques used to measure different assets and liabilities at fair value and includes the level within the fair value hierarchy in which the assets and liabilities are categorized.

Investments

Level 1 investments are valued using quoted market prices. Level 2 investments are valued using market consensus prices that are corroborated by observable market data and quoted market prices for similar assets and liabilities. Level 3 investments are valued at fair value as determined in good faith by the Valuation Designee, based on input of the Valuation Designee’s personnel and independent valuation firms that have been engaged at the direction of the Valuation Designee to assist in the valuation of each portfolio investment without a readily available market quotation at least every other quarter under a valuation policy and a consistently applied valuation process. This valuation process is conducted at the end of each fiscal quarter, with each portfolio investment being reviewed at least every other quarter (subject to a de minimis threshold) with approximately 50% (based on the fair value of the portfolio company investments) of the Company’s valuations of debt and equity investments without readily available market quotations subject to review by an independent valuation firm. All investments as of September 30, 2025 were valued using Level 3 inputs. All investments as of September 30, 2024, with the exception of one portfolio company investment (Level 1 investments), were valued using Level 3 inputs. As of September 30, 2025 and September 30, 2024, all money market funds included in cash and cash equivalents and restricted cash and cash equivalents were valued using Level 1 inputs and all forward currency contracts and interest rate swaps were valued using Level 2 inputs.

When determining fair value of Level 3 debt and equity investments, the Valuation Designee takes into account the following factors, where relevant: the enterprise value of a portfolio company, the nature and realizable value of any collateral, the portfolio company’s ability to make payments and its earnings and discounted cash flows, the markets in which the portfolio company does business, comparisons to publicly traded securities, and changes in the interest rate environment and the credit markets generally that affect the price at which similar investments are made and other relevant factors. The primary method for determining enterprise value uses a multiple analysis whereby appropriate multiples are applied to the portfolio company’s net income before net interest expense, income tax expense, depreciation and amortization (“EBITDA”). A portfolio company’s EBITDA can include pro-forma adjustments for items such as acquisitions, divestitures, or expense reductions. The enterprise value analysis is performed to determine the value of equity investments and to determine if debt investments are credit impaired. If debt investments are credit impaired, the Valuation Designee will use the enterprise value analysis or a liquidation basis analysis to determine fair value. For debt investments that are not determined to be credit impaired, the Valuation Designee uses a market interest rate yield analysis to determine fair value.

In addition, for certain debt investments, the Valuation Designee bases its valuation on indicative bid and ask prices provided by an independent third-party pricing service. Bid prices reflect the highest price that the Company and others could be willing to pay. Ask prices represent the lowest price that the Company and others could be willing to accept. The Valuation Designee generally uses the midpoint of the bid/ask range as its best estimate of fair value of such investment.

Due to the inherent uncertainty of determining the fair value of Level 3 investments that do not have a readily available market value, the fair value of the investments could differ significantly from the values that would have been used had a ready market existed for such investments and could differ materially from the values that are ultimately received or settled. Further, such investments are generally subject to legal and other restrictions or otherwise are less liquid than publicly traded instruments. If the Company were required to liquidate a portfolio investment in a forced or liquidation sale, the Company could realize significantly less than the value at which such investment had previously been recorded. The Company’s investments are subject to market risk. Market risk is the potential for changes in the value due to market changes. Market risk is directly impacted by the volatility and liquidity in the markets in which the investments are traded.

The following tables present fair value measurements of the Company’s investments and indicate the fair value hierarchy of the valuation techniques utilized to determine such fair value as of September 30, 2025 and September 30, 2024:

(1)Refer to the Consolidated Schedules of Investments for further details.

(2)Included in cash and cash equivalents and restricted cash and cash equivalents on the Consolidated Statements of Financial Condition.

The net change in unrealized appreciation (depreciation) for the years ended September 30, 2025, 2024, 2023 reported within the net change in unrealized appreciation (depreciation) on investments in the Company’s Consolidated Statements of Operations attributable to the Company’s Level 3 assets held at the end of each year was $10,851, ($25,138) and $1,324, respectively.

The following tables present the changes in investments measured at fair value using Level 3 inputs for the years ended September 30, 2025 and 2024:

The following tables present quantitative information about the significant unobservable inputs of the Company’s Level 3 investments as of September 30, 2025 and September 30, 2024.

(1)Unobservable inputs were weighted by the relative fair value of the instruments.

(2)$67 of loans at fair value were valued using the market comparable companies approach only.

(3)$46,465 of loans at fair value were valued using the market comparable companies approach only.

(4)The Company valued $6,600,901 and $1,002,879 of one stop loans using EBITDA and revenue multiples, respectively. All one stop loans were also valued using the market rate approach.

(5)$132 of loans at fair value were valued using the market comparable companies approach only.

(6)The Company valued $563,467 and $82,815 of equity investments using EBITDA and revenue multiples, respectively.

(1)Unobservable inputs were weighted by the relative fair value of the instruments.

(2)$2,807 of loans at fair value were valued using the market comparable companies approach only.

(3)$64,786 of loans at fair value were valued using the market comparable companies approach only.

(4)The Company valued $6,036,312 and $1,021,265 of one stop loans using EBITDA and revenue multiples, respectively. All one stop loans were also valued using the market rate approach.

(5)$435 of loans at fair value were valued using the market comparable companies approach only.

(6)The Company valued $505,597 and $72,823 of equity investments using EBITDA and revenue multiples, respectively.

The above tables are not intended to be all-inclusive but rather to provide information on significant unobservable inputs and valuation techniques used by the Valuation Designee.

The significant unobservable inputs used in the fair value measurement of the Company’s debt and equity investments are EBITDA multiples, revenue multiples and market interest rates. The Valuation Designee uses EBITDA multiples and, to a lesser extent, revenue multiples on the Company’s debt and equity investments to determine any credit gains or losses. Increases or decreases in either of these inputs in isolation would have resulted in a significantly lower or higher fair value measurement. The Valuation Designee uses market interest rates for loans to determine if the effective yield on a loan is commensurate with the market yields for that type of loan. If a loan’s effective yield was significantly less than the market yield for a similar loan with a similar credit profile, then the resulting fair value of the loan could have been lower.

Other Financial Assets and Liabilities

ASC Topic 820 requires disclosure of the fair value of financial instruments for which it is practical to estimate such value. As a result, with the exception of the line item titled “debt” which is reported at cost, all assets and liabilities approximate fair value on the Consolidated Statements of Financial Condition due to their short maturity. The fair value of the Company's 2026 Notes, 2027 Notes, 2028 Notes and 2029 Notes (as defined in Note 7) is based on vendor pricing received by the Company, which is considered a Level 2 input. The fair value of the Company’s remaining debt is estimated using Level 3 inputs by discounting remaining payments using comparable market rates or market quotes for similar instruments at the measurement date, if available.

The following are the carrying values and fair values of the Company’s debt as of September 30, 2025 and September 30, 2024.

(1) As of September 30, 2025 and September 30, 2024, carrying value is inclusive of an adjustment for the change in fair value of an effective hedge accounting relationship related to the 2028 and 2029 Notes. See Note 5 for additional information.

Note 7. Borrowings

In accordance with the 1940 Act, with certain limited exceptions, prior to February 6, 2019, the Company was allowed to borrow amounts such that its asset coverage, as defined in the 1940 Act, was at least 200% after such borrowing. On February 5, 2019, the Company’s stockholders voted to approve the asset coverage requirement decrease to 150% from 200% in accordance with Section 61(a)(2) of the 1940 Act. Effective February 6, 2019, the reduced asset coverage requirement permits the Company to have a ratio of total consolidated assets to outstanding indebtedness of 2:1 as compared to a maximum of 1:1 under the 200% asset coverage requirement. As of September 30, 2025, the Company’s asset coverage for borrowed amounts was 180.2%.

2024 Debt Securitization: On November 18, 2024, the Company completed a $2,200,500 term debt securitization (the “2024 Debt Securitization”). The notes offered in the 2024 Debt Securitization (“the 2024 Notes”) were issued by the 2024 Issuer and were backed by a diversified portfolio of senior secured loans. The transaction was executed through a private placement which consisted of $1,192,400 of Aaa/AAA Class A-1R Senior Secured Floating Rate Notes due 2036 (the “Class A-1R 2024 Notes”), which bear interest at three-month SOFR plus 1.56%; $171,600 of AAA Class A-2RR Senior Secured Floating Rate Notes due 2036, which bear interest at three-month SOFR plus 1.75% (the “Class A-2RR 2024 Notes”); $165,000 of AA Class B-R Senior Secured Floating Rate Notes, which bear interest at three-month SOFR plus 1.70% (the “Class B-R Notes”); $154,000 of A Class C-R Senior Secured Floating Rate Notes, which bear interest at three-month SOFR plus 2.10%; and $517,500 of Subordinated Notes due 2124 which do not bear interest (the “Subordinated Notes” and together with the Secured Notes, the “2024 Notes”). The Company indirectly retained all of the Class B-R, Class C-R and Subordinated Notes.

Through October 20, 2028, all principal collections received on the underlying collateral may be used by the 2024 Issuer to purchase new collateral under the direction of the Investment Adviser, in its capacity as collateral manager of the 2024 Issuer and in accordance with the Company’s investment strategy and subject to customary conditions set forth in the documents governing the 2024 Debt Securitization, allowing the Company to maintain the initial leverage in the 2024 Debt Securitization. The 2024 Notes are scheduled to mature on October 20, 2036. The Subordinated 2024 Notes are due in 2124. The Class A-1R and Class A-2RR 2024 Notes are included in the September 30, 2025 Consolidated Statement of Financial Condition as debt of the company. As of September 30, 2025, the Class B-R, Class C-R and Subordinated 2024 Notes were eliminated in consolidation.

As of September 30, 2025, there were 126 portfolio companies with a total fair value of $2,161,579 securing the 2024 Debt Securitization. The pool of loans in the 2024 Debt Securitization must meet certain requirements, including asset mix and concentration, collateral coverage, term, agency rating, minimum coupon, minimum spread and sector diversity requirements.

The interest charged under the 2024 Debt Securitization is based on three-month SOFR. The three-month SOFR in effect as of September 30, 2025 based on the last interest rate reset was 4.3%.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest, average stated interest rates and average outstanding balances for the 2024 Debt Securitization were as follows:

As of September 30, 2025, the classes, amounts, ratings and interest rates in effect (expressed as a spread to three-month SOFR) of the Class A-1R and A-2RR 2024 Notes are as follows:

As part of the 2024 Debt Securitization, the Company entered into a master loan sale agreement that provides for the sale of assets on the 2024 Debt Securitization closing date as well as future sales from the Company to the 2024 Issuer through the BDC CLO 8 Depositor, (1) the Company sold and/or contributed to the BDC CLO 8 Depositor the remainder of its ownership interest in the portfolio company investments securing the 2024 Debt Securitization and participations for the purchase price and other consideration set forth in the master loan sale agreement and (2) the BDC CLO 8 Depositor, in turn, sold to the 2024 Issuer all of its ownership interest in such portfolio loans and participations for the purchase price and other consideration set forth in the master loan sale agreement. Following these transfers, the 2024 Issuer, and not the BDC CLO 8 Depositor or the Company, holds all of the ownership interest in such portfolio company investments and participations.

2018 Debt Securitization: On November 16, 2018, the Company completed a $602,400 term debt securitization (the “2018 Debt Securitization”). The notes offered in the 2018 Debt Securitization (the “2018 Notes”) were issued by the 2018 Issuer, a subsidiary of the 2018 CLO Depositor, and were backed by a diversified portfolio of senior secured and second lien loans. The transaction was executed through a private placement which, through November 18, 2024, consisted of approximately $327,000 of AAA/AAA Class A 2018 Notes, which bore interest at three-month LIBOR plus 1.48%; $61,200 of AA Class B 2018 Notes, which bore interest at three-month LIBOR plus 2.10%; $20,000 of A Class C-1 2018 Notes, which bore interest at three-month LIBOR plus 2.80%; $38,800 of A Class C-2 2018 Notes, which bore interest at three-month LIBOR plus 2.65%; $42,000 of BBB- Class D 2018 Notes, which bore interest at three-month LIBOR plus 2.95%; and $113,400 of Subordinated 2018 Notes which did not bear interest. The Company indirectly retained all of the Class C-2, Class D and Subordinated 2018 Notes. The Class A, Class B and Class C-1 2018 Notes are included in the September 30, 2024 Consolidated Statements of Financial Condition as debt of the Company. As of September 30, 2024, the Class C-2, Class D and Subordinated 2018 Notes were eliminated in consolidation.

Through January 20, 2023, the 2018 Issuer was permitted to use all principal collections received on the underlying collateral to purchase new collateral under the direction of the Investment Adviser, in its capacity as collateral manager of the 2018 Issuer and in accordance with the Company’s investment strategy, allowing the Company to maintain the initial leverage in the 2018 Debt Securitization. For the years ended September 30, 2024 and 2023, the Company had repayments on the 2018 Notes of $158,712 and $19,503, respectively.

On November 18, 2024, in connection with the 2024 Debt Securitization, the 2018 Issuer redeemed the outstanding 2018 Notes pursuant to the terms of the indenture governing the 2018 Notes. Following such redemption, the agreements which governed the 2018 Debt Securitization were terminated. The 2018 Notes would have otherwise matured on January 20, 2031.

As of September 30, 2024, there were 44 portfolio companies with a total fair value of $351,446 securing the 2018 Notes. The pool of loans in the 2018 Debt Securitization were required to meet certain requirements, including asset mix and concentration, collateral coverage, term, agency rating, minimum coupon, minimum spread and sector diversity requirements.

The interest charged under the 2018 Debt Securitization was based on three-month SOFR plus a spread adjustment of 0.26161%. For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest, average stated interest rates and average outstanding balances for the 2018 Debt Securitization were as follows:

As part of the 2018 Debt Securitization, GBDC entered into a master loan sale agreement under which GBDC agreed to directly or indirectly sell or contribute certain senior secured and second lien loans (or participation interests therein) to the 2018 Issuer and to purchase or otherwise acquire the LLC equity interests in the Subordinated 2018 Notes. As of September 30, 2024, the 2018 Notes (other than the Subordinated 2018 Notes) were the secured obligations of the 2018 Issuer and indentures governing the 2018 Notes include customary covenants and events of default.

GCIC 2018 Debt Securitization: Effective September 16, 2019, the Company assumed, as a result of the GCIC Merger, a $908,195 term debt securitization (the “GCIC 2018 Debt Securitization”). The GCIC 2018 Debt Securitization was originally completed on December 13, 2018. The notes offered in the GCIC 2018 Debt Securitization (the “GCIC 2018 Notes”) were issued by the GCIC 2018 Issuer, a subsidiary of GCIC 2018 CLO Depositor, and were secured by a diversified portfolio of senior secured and second lien loans. Through November 18, 2024, the GCIC 2018 Debt Securitization consisted of $490,000 of AAA/AAA Class A-1 GCIC 2018 Notes, $38,500 of AAA Class A-2 GCIC 2018 Notes, and $18,000 of AA Class B-1 GCIC 2018 Notes. In partial consideration for the loans transferred to the GCIC 2018 Issuer as part of the GCIC 2018 Debt Securitization, the GCIC 2018 CLO Depositor received and retained $27,000 of Class B-2 GCIC 2018 Notes, $95,000 of Class C GCIC 2018 Notes and $60,000 of Class D GCIC 2018 Notes and $179,695 of Subordinated GCIC 2018 Notes. On December 21, 2020, the Company and the GCIC 2018 Issuer amended the GCIC 2018 Debt Securitization to, among other things, (a) refinance the issued Class A-2 GCIC 2018 Notes issued by the GCIC 2018 Issuer by redeeming in full the $38,500 of Class A-2 GCIC 2018 Notes and issuing new Class A-2-R GCIC 2018 Notes in an aggregate principal amount of $38,500 that bore interest at a rate of 2.498%, which is a decrease from the rate of 4.665% of the Class A-2 GCIC 2018 Notes and (b) provide for a non-called period, during which the Class A-2-R GCIC 2018 Notes cannot be redeemed, from December 21, 2020 to but excluding June 21, 2021. The Class A-1, Class A-2-R and Class B-1 GCIC 2018 Notes are included in the September 30, 2024 Consolidated Statements of Financial Condition as debt of the Company. As of September 30, 2024, the Class B-2, Class C and Class D GCIC 2018 Notes and the Subordinated GCIC 2018 Notes were eliminated in consolidation.

Through January 20, 2023, the GCIC 2018 Issuer was permitted to use all principal collections received on the underlying collateral to purchase new collateral under the direction of the Investment Adviser in its capacity as collateral manager of the GCIC 2018 Issuer and in accordance with the Company’s investment strategy, allowing the Company to maintain the initial leverage in the GCIC 2018 Debt Securitization. For the years ended September 30, 2024 and 2023, the Company had repayments on the GCIC 2018 Notes of $260,755 and $32,973, respectively.

On November 18, 2024, in connection with the 2024 Debt Securitization, the GCIC 2018 Issuer redeemed the outstanding GCIC 2018 Notes pursuant to the terms of the indenture governing such GCIC 2018 Notes. Following such redemption, the agreements that governed the GCIC 2018 Debt Securitization were terminated. The GCIC 2018 Notes would have otherwise matured on January 20, 2031, and the Subordinated GCIC 2018 Notes would have otherwise matured on December 13, 2118.

As of September 30, 2024, there were 58 portfolio companies with a total fair value of $524,168 securing the GCIC 2018 Notes. The pool of loans in the GCIC 2018 Debt Securitization were required to meet certain requirements, including asset mix and concentration, collateral coverage, term, agency rating, minimum coupon, minimum spread and sector diversity requirements.

The interest charged under the GCIC 2018 Debt Securitization was based on three-month SOFR plus a spread adjustment of 0.26161%. For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest, average stated interest rates and average outstanding balances for the GCIC 2018 Debt Securitization were as follows:

As part of the GCIC 2018 Debt Securitization, GBDC assumed in the GCIC Merger a master loan sale agreement under which GBDC agreed to directly or indirectly sell or contribute certain senior secured and second lien loans (or participation interests therein) to the GCIC 2018 Issuer and to purchase or otherwise acquire the LLC equity interests in the GCIC Subordinated 2018 Notes. As of September 30, 2024, the GCIC 2018 Notes (other than the GCIC Subordinated 2018 Notes) were the secured obligations of the GCIC 2018 Issuer and indentures governing the GCIC 2018 Notes include customary covenants and events of default.

GBDC 3 2021 Debt Securitization: Effective June 3, 2024, the Company assumed, as a result of the GBDC 3 Merger, a $398,850 term debt securitization (the “GBDC 3 2021 Debt Securitization”). The GBDC 3 2021 Debt Securitization was originally completed on March 11, 2021. The GBDC 3 2021 Notes were issued by the GBDC 3 2021 Issuer and were backed by a diversified portfolio of senior secured and second lien loans. Through November 18, 2024, the GBDC 3 2021 Notes offered in the GBDC 3 2021 Debt Securitization consisted of $224,000 of AAA Class A GBDC 3 2021 Notes, which bore interest at the three-month SOFR plus 1.60%; $28,000 of AA Class B GBDC 3 2021 Notes, which bore interest at the three-month SOFR plus 1.85%; $36,000 of A Class C-1 GBDC 3 2021 Notes, which bore interest at the three-month SOFR plus 2.80%; $10,000 A Class C-2 GBDC 3 2021 Notes, which bore interest at 3.91%; up to $28,000 of BBB- Class D GBDC 3 2021 Notes, which were unfunded on the closing date of the GBDC 3 2021 Debt Securitization and which, if funded, would bear interest at the three-month SOFR plus a spread set in connection with the funding date but which in no event will be greater than 5.00% (the Class D GBDC 3 2021 Notes, together with the Class A GBDC 3 2021 Notes, the Class B GBDC 3 2021 Notes, the Class C-1 GBDC 3 2021 Notes and the Class C-2 GBDC 3 2021 Notes are referred to as the “Secured GBDC 3 2021 Notes”); and approximately $100,850 of Subordinated GBDC 3 2021 Notes, which did not bear interest. The Class A GBDC 3 2021 Notes, the Class B GBDC 3 2021 Notes, the Class C-1 GBDC 3 2021 Notes, and the Class C-2 GBDC 3 2021 Notes were issued through a private placement through Deutsche Bank Securities Inc. The GBDC 3 2021 Issuer indirectly retained all of the Class D GBDC 3 2021 Notes and Subordinated GBDC 3 2021 Notes which were eliminated in consolidation. The Class A, Class B, Class C-1, and Class C-2 GBDC 3 2021 Notes are included in the September 30, 2024 Consolidated Statements of Financial Condition as debt of the Company.

Through April 15, 2025, the GBDC 3 2021 Issuer was permitted to use all principal collections received on the underlying collateral to purchase new collateral under the direction of the Investment Adviser, in its capacity as collateral manager of the GBDC 3 2021 Issuer, in accordance with the Company’s investment strategy and subject to customary conditions set forth in the documents governing the GBDC 3 2021 Debt Securitization, allowing the Company to maintain the initial leverage in the GBDC 3 2021 Debt Securitization.

On November 18, 2024, in connection with the 2024 Debt Securitization, the GBDC 3 2021 Issuer redeemed the outstanding GBDC 3 2021 Notes pursuant to the terms of the indenture governing such GBDC 3 2021 Notes. Following such redemption, the agreements which governed the GBDC 3 2021 Debt Securitization were terminated. The redemption of the GBDC 3 2021 Notes resulted in a realized loss on the extinguishment of debt of $48 for the three months ended December 31, 2024, which represented the unamortized discount on the GBDC 3 2021 Notes assumed as a result on the GBDC 3 Merger, at termination. The Secured GBDC 3 2021 Notes would have otherwise matured on April 15, 2033 and the Subordinated GBDC 3 2021 Notes would have otherwise matured in 2121.

As of September 30, 2024, there were 81 portfolio companies with total fair value of $395,682 securing the GBDC 3 2021 Notes. The pool of loans in the GBDC 3 2021 Debt Securitization were required to meet certain requirements, including asset mix and concentration, collateral coverage, term, agency rating, minimum coupon, minimum spread and sector diversity requirements.

The interest charged under the GBDC 3 2021 Debt Securitization was based on three-month SOFR plus a spread adjustment of 0.26161%. For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest expense, average stated interest rates and average outstanding balances for the GBDC 3 2021 Debt Securitization were as follows:

As part of the GBDC 3 2021 Debt Securitization, GBDC assumed in the GBDC 3 Merger a master loan sale agreement under which GBDC agreed to directly or indirectly sell or contribute certain senior secured and second lien loans (or participation interests therein) to the GBDC 3 2021 Issuer and to purchase or otherwise acquire the LLC equity interests in the Subordinated GBDC 3 2021 Notes. As of September 30, 2024, the Secured GBDC 3 2021 Notes (other than the Subordinated GBDC 3 2021 Notes) were the secured obligations of the GBDC 3 2021 Issuer and indentures governing the Secured GBDC 3 2021 Notes include customary covenants and events of default.

GBDC 3 2022 Debt Securitization: Effective June 3, 2024, the Company assumed, as a result of the GBDC 3 Merger, a $401,750 asset-backed securitization (the “GBDC 3 2022 Debt Securitization”). The GBDC 3 2022 Debt Securitization was originally completed on January 25, 2022. The notes offered in the GBDC 3 2022 Debt Securitization were issued by the GBDC 3 2022 Issuer and are backed by a diversified portfolio of senior secured loans. The notes offered in the GBDC 3 2022 Debt Securitization consist of $252,000 of Class A Senior Secured Floating Rate Notes, which bear interest at a benchmark interest rate, which will be based on three-month term SOFR, plus 2.00% (the “Secured GBDC 3 2022 Notes”) and $149,750 of Subordinated Notes, which do not bear interest (the “Subordinated GBDC 3 2022 Notes” and, together with the Secured GBDC 3 2022 Notes, the “GBDC 3 2022 Notes”). The Secured GBDC 3 2022 Notes were issued through a private placement through Deutsche Bank Securities Inc. The GBDC 3 2022 Issuer indirectly retained all of the Subordinated GBDC 3 2022 Notes, and the Subordinated GBDC 3 2022 Notes were eliminated in consolidation. The Secured GBDC 3 2022 Notes are included in the September 30, 2024 Consolidated Statements of Financial Condition as debt of the Company.

Through January 25, 2024, the GBDC 3 2022 Issuer was permitted to use all principal collections received on the underlying collateral to purchase new collateral under the direction of the Investment Adviser, in its capacity as collateral manager of the GBDC 3 2022 Issuer, in accordance with the Company’s investment strategy, allowing the Company to maintain the initial leverage in the GBDC 3 2022 Debt Securitization. There were repayments on the GBDC 3 2022 Notes of $14,751 during the period June 3, 2024 through September 30, 2024.

On August 1, 2025, the GBDC 3 2022 Issuer redeemed the outstanding GBDC 3 2022 Notes pursuant to the terms of the indenture governing such GBDC 3 2022 Notes. Following such redemption, the agreements that governed the GBDC 3 2022 Debt Securitization were terminated. The GBDC 3 2022 Notes would have otherwise matured on January 18, 2030 and the Subordinated GBDC 3 2022 Notes would have otherwise matured on January 25, 2122.

As of September 30, 2024, there were 55 portfolio companies, respectively, with a total fair value of $377,755, securing the GBDC 3 2022 Debt Securitization. The pool of loans in the GBDC 3 2022 Debt Securitization were required to meet certain requirements, including asset mix and concentration, collateral coverage, term, agency rating, minimum coupon, minimum spread and sector diversity requirements.

The interest charged under the GBDC 3 2022 Debt Securitization was based on three-month term SOFR.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest expense, average stated interest rates and average outstanding balances for the GBDC 3 2022 Debt Securitization were as follows:

As part of the GBDC 3 2022 Debt Securitization, GBDC assumed in the GBDC 3 Merger a master loan sale agreement under which GBDC agreed to directly or indirectly sell or contribute certain senior secured loans (or participation interests therein) to the GBDC 3 2022 Issuer and to purchase or otherwise acquire the LLC equity interests in the Subordinated GBDC 3 2022 Notes. As of September 30, 2024, the Secured GBDC 3 2022 Notes (other than the Subordinated GBDC 3 2022 Notes) were the secured obligations of the Secured GBDC 3 2022 and indentures governing the Secured GBDC 3 2022 Notes include customary covenants and events of default.

GBDC 3 2022-2 Debt Securitization: Effective June 3, 2024, the Company assumed, as a result of the GBDC 3 Merger, a $386,600 term debt securitization (the “GBDC 3 2022-2 Debt Securitization”). The GBDC 3 2022-2 Debt Securitization was originally completed on December 14, 2022. The notes offered in the GBDC 3 2022-2 Debt Securitization (the “GBDC 3 2022-2 Notes”) were issued by the GBDC 3 2022-2 Issuer and were backed by a diversified portfolio of senior secured and second lien loans. Through December 16, 2024, the GBDC 3 2022-2 Notes offered in the GBDC 3 2022-2 Debt Securitization consisted of $140,000 of AAA Class A GBDC 3 Senior Secured Floating Rate Notes due 2034, which bore interest at the three-month term SOFR plus 2.60%; $38,800 of AA Class B GBDC 3 Senior Secured Floating Rate Notes due 2034, which bore interest at the three-month term SOFR plus 3.09% (the “Class B GBDC 3 2022-2 Notes” and, together with the Class A GBDC 3 2022-2 Notes, the “Secured GBDC 3 2022-2 Notes”); $85,000 of AAA Class A GBDC 3 Senior Secured Floating Rate Loans maturing 2034, which bore interest at the three-month term SOFR plus 2.60% (the “Class A GBDC 3 2022-2 Loans” and, together with the Secured GBDC 3 2022-2 Notes, the “Secured GBDC 3 2022-2 Debt”); and $122,800 of Subordinated Notes due 2122 (the “Subordinated GBDC 3 2022-2 Notes”), which did not bear interest. The GBDC 3 2022-2 Issuer indirectly retained all of the Class B GBDC 3 2022-2 Notes and Subordinated GBDC 3 2022-2 Notes which were eliminated in consolidation. The Class A GBDC 3 2022-2 Notes and Class A GBDC 3 2022-2 Loans are included in the September 30, 2024 Consolidated Statement of Financial Condition as debt of the Company.

Through January 18, 2026, the GBDC 3 2022-2 Issuer was permitted to us all principal collections received on the underlying collateral to purchase new collateral under the direction of the Investment Adviser, in its capacity as collateral manager of the GBDC 3 2022-2 Issuer, in accordance with the Company’s investment strategy and subject to customary conditions set forth in the documents governing the GBDC 3 2022-2 Debt Securitization, allowing the Company to maintain the initial leverage in the GBDC 3 2022-2 Debt Securitization.

On December 16, 2024, the GBDC 3 2022-2 Issuer redeemed the outstanding GBDC 3 2022-2 Notes pursuant to the terms of the indenture governing such GBDC 3 2022-2 Notes. Following such redemption, the agreements which governed the GBDC 3 2022-2 Debt Securitization were terminated. The Secured GBDC 3 2022-2 Notes and Class A GBDC 3 2022-2 Loans would have otherwise matured on January 18, 2034. The Subordinated GBDC 3 2022-2 Notes would have otherwise matured on December 14, 2122.

As of September 30, 2024, there were 73 portfolio companies with a total fair value of $377,471 securing the GBDC 3 2022-2 Debt Securitization. The pool of loans in the GBDC 3 2022-2 Debt Securitization were required to meet certain requirements, including asset mix and concentration, collateral coverage, term, agency rating, minimum coupon, minimum spread and sector diversity requirements. The interest charged under the GBDC 3 2022-2 Debt Securitization was based on three-month term SOFR. For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest expense, average stated interest rates and average outstanding balances for the GBDC 3 2022-2 Debt Securitization were as follows:

As part of the GBDC 3 2022-2 Debt Securitization, GBDC assumed in the GBDC 3 Merger a master loan sale agreement under which GBDC agreed to directly or indirectly sell or contribute certain senior secured and second lien loans (or participation interests therein) to the GBDC 3 2022-2 Issuer and to purchase or otherwise acquire the LLC equity interests in the Subordinated GBDC 3 2022-2 Notes. As of September 30, 2024, the Secured GBDC 3 2022-2 Notes (other than the Subordinated GBDC 3 2022-2 Notes) were the secured obligations of the GBDC 3 2022-2 Issuer and indentures governing the Secured GBDC 3 2022-2 Notes include customary covenants and events of default.

The Investment Adviser serves or served as collateral manager to each of the 2018 Issuer, GCIC 2018 Issuer, GBDC 3 2021 Issuer, GBDC 3 2022 Issuer, GBDC 3 2022-2 Issuer and the 2024 Issuer under separate collateral management agreements and receives a fee for providing these services. The total fees payable by the Company under the Investment Advisory Agreement are reduced by an amount equal to the total aggregate fees paid to the Investment Adviser by each of the 2018 Issuer, GCIC 2018 Issuer, GBDC 3 2021 Issuer, GBDC 3 2022 Issuer, GBDC 3 2022-2 and the 2024 Issuer for rendering such collateral management services.

GBDC 3 DB Credit Facility: Effective June 3, 2024, the Company assumed, as a result of the GBDC 3 Merger, a loan financing and servicing agreement (as amended, the “GBDC 3 DB Credit Facility”), with the Company and GBDC 3 Funding, as equity holder and as servicer, the lenders from time to time parties thereto, Deutsche Bank AG, New York Branch, as facility agent, the other agents parties thereto, each of the entities from time to time party thereto as securitization subsidiaries and Deutsche Bank Trust Company Americas, as collateral agent and as collateral custodian. The GBDC 3 DB Credit Facility was originally entered into on September 10, 2019 (the “GBDC 3 DB Credit Facility Effective Date”). On November 19, 2024, all amounts outstanding under the GBDC 3 DB Credit Facility were repaid, following which the agreements governing the GBDC 3 DB Credit Facility were terminated. The period during which GBDC 3 Funding may have requested drawdowns under the “GBDC 3 DB Credit Facility (the “Revolving Period”) commenced on the GBDC 3 DB Credit Facility Effective Date and would have continued through April 10, 2025. Prior to termination, the GBDC 3 DB Credit Facility allowed GBDC 3 Funding to borrow up to $625,000, subject to leverage and borrowing base restrictions, and had a maturity date of April 10, 2028.

Prior to termination, the GBDC 3 DB Credit Facility bore interest at the applicable base rate plus 2.30% per annum during the Revolving Period and 2.80% after the Revolving Period. The base rate under the GBDC 3 DB Credit

Facility was (i) the three-month Canadian Overnight Repo Rate Average (“CORRA”) plus an adjustment equal to 0.32138% with respect to any advances denominated in Canadian dollars, (ii) the three-month EURIBOR with respect to any advances denominated in euros, (iii) the three-month Bank Bill Swap Rate with respect to any advances denominated in Australian dollars, (iv) the daily simple Sterling Overnight Index Average with respect to any advances denominated U.K. pound sterling, the daily simple Swiss Average Rate Overnight with respect to any advances denominated in Swiss francs, (v) the three-month Copenhagen Interbank Offered Rate with respect to any advances denominated in Danish krones, (vi) the three-month Bank Bill Benchmark Rate with respect to any advances denominated in New Zealand dollars, (vii) the three-month Norwegian Krone Interbank Offered Rate with respect to any advances denominated in Norwegian krona, (viii) the three-month Stockholm Interbank Offered Rate with respect to any advances denominated in Swedish krona, and (ix) the three-month term SOFR with respect to any other advances. A syndication/agent fee was payable to the facility agent each quarter and was calculated based on the aggregate commitments outstanding each day during the preceding collection period at a rate of 1/360 of 0.25% of the aggregate commitments on each day. In addition, a non-usage fee of 0.25% per annum was payable on the undrawn amount under the GBDC 3 DB Credit Facility, and, during the Revolving Period, an additional fee based on unfunded commitments of the lenders could have been payable if borrowings under the GBDC 3 DB Credit Facility did not exceed a minimum utilization percentage threshold. A prepayment fee would have been payable in the event of any permanent reduction in commitments of the GBDC 3 DB Credit Facility in the amount of 0.50% or 0.25% of the amount of the reduction during the first or second year after the Effective Date, respectively.

The GBDC 3 DB Credit Facility was secured by all of the assets held by GBDC 3 Funding. GBDC 3 Funding made customary representations and warranties and was required to comply with various covenants, reporting requirements and other customary requirements for similar credit facilities. The borrowings under the GBDC 3 DB Credit Facility were subject to the leverage restrictions contained in the 1940 Act.

As of September 30, 2024, the Company had outstanding debt under the GBDC 3 DB Credit Facility of $411,489.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest expense, average stated interest rates and average outstanding balances for the “GBDC 3 DB Credit Facility were as follows:

(1)The average stated interest rate reflects the translation of the stated interest expense and borrowings in foreign currencies to U.S. dollar.

JPM Credit Facility: On February 11, 2021, the Company entered into a senior secured revolving credit facility (as amended, the “JPM Credit Facility”) with the Company, as borrower, JPMorgan Chase Bank N.A., as administrative agent and as collateral agent, and the lenders from time to time party thereto which, as of September 30, 2025, allowed the Company to borrow up to $1,997,500 in U.S. dollars and certain agreed upon foreign currencies (“Outstanding Commitments”), subject to leverage and borrowing base restrictions. Through a series of agreements, most recently on November 15, 2024 and December 6, 2024, the Company, through the accordion feature, increased the aggregate commitments under the JPM Credit Facility from $1,822,500 to $1,997,500. On April 4, 2025, the Company amended and restated the JPM Credit Facility to among other things, (i) change the applicable margin to a range of 1.525% to 1.775% for any Term Benchmark Loan or RFR Loan (as defined in the JPM Credit Facility) or a range of 0.525% to 0.775% for any ABR Loan (each as defined in the JPM Credit Facility), (ii) reduce the unused fee rate on all unused commitments to 0.325% from 0.375%, (iii) extend the maturity date to April 4, 2030 from August 6, 2029 and (iv) amend the accordion provision to permit increases to the total commitments to up to $3,000,000.

The JPM Credit Facility provides for the issuance of letters of credit in an initial aggregate face amount of up to $23,750, subject to increase or reduction from time to time pursuant to the terms of the JPM Credit Facility.

The JPM Credit Facility is secured by a first priority security interest in substantially all of the assets of the Company and certain of the Company’s subsidiaries thereunder.

Borrowings for any Term Benchmark Loan or RFR Loan (each as defined in the JPM Credit Facility) under the JPM Credit Facility bear interest at the applicable base rate plus a margin of 1.525% if the gross borrowing base is equal to or greater than 2.0 times the Outstanding Commitments,1.650% if the gross borrowing base is less than 2.0 times and equal to or greater than 1.60 times the Outstanding Commitments or 1.775% if the gross borrowing base is less than 1.60 times the Outstanding Commitments, subject to compliance with a borrowing base test. The applicable base rate under the JPM Credit Facility is (i) one-month SOFR with respect to any advances denominated in U.S. dollars plus an adjustment of 0.10%, (ii) SONIA with respect to any advances denominated in U.K. pound sterling plus an adjustment of 0.0326%, (iii) one-month EURIBOR with respect to any advances denominated in Euros, (iv) CORRA with respect to any advances denominated in Canadian Dollars plus an adjustment of 0.029547%, (v) Australian Bank Bill Swap Bid Rate (“BBSY”) with respect to any advances denominated in Australian Dollars plus an adjustment of 0.20% and (vi) the relevant rate as defined in the JPM Credit Facility for borrowings in other currencies. Borrowings for any ABR Loan (as defined in the JPM Credit Facility) bear interest at the applicable base rate plus a margin of 0.525% if the gross borrowing base is equal to or greater than 2.0 times the Outstanding Commitments,0.650% if the gross borrowing base is less than 2.0 times and equal to or greater than 1.60 times the Outstanding Commitments or 0.775% if the gross borrowing base is less than 1.60 times the Outstanding Commitments. As of June 30, 2025, the applicable margin for Term Benchmark Loans and RFR Loans (as defined in the JPM Credit Facility) was 1.525% and the applicable margin for ABR Loans (as defined in the JPM Credit Facility) was 0.525%.

The Company pays a commitment fee of 0.325% per annum on the daily unused portion of commitments under the JPM Credit Facility. The Company is also required to pay letter of credit participation fees and a fronting fee on the daily amount of any lender’s exposure with respect to any letters of credit issued at the request of the Company under the JPM Credit Facility. The JPM Credit Facility matures on April 4, 2030 and requires mandatory prepayment of interest and principal upon certain events during theone year amortization period of the facility.

As of September 30, 2025 and September 30, 2024, the Company had outstanding debt of $1,098,437 and $956,590, respectively, andno letters of credit outstanding under the JPM Credit Facility.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest and facility fees, average stated interest rates and average outstanding balances for the JPM Credit Facility were as follows:

(1)The average stated interest rate reflects the translation of the stated interest expense and borrowings in foreign currencies to U.S. dollar.

2024 Notes: On October 2, 2020, the Company issued $400,000 in aggregate principal amount of unsecured notes (the “2024 Notes”), and on October 15, 2021, the Company issued an additional $100,000 in aggregate principal amount of 2024 Notes under the same terms of the original issuance, other than the issue date and the issue price. On April 8, 2024, the Company redeemed $500,000 in aggregate principal amount of the 2024 Notes. The 2024 Notes were redeemed at 100% of the principal amount, plus the accrued and unpaid interest thereon. The 2024 Notes bore interest at a rate of 3.375% per year payable semiannually in arrears on April 15 and October 15 of each year, commencing on April 15, 2021. The 2024 Notes would otherwise have matured on April 15, 2024.

The 2024 Notes were the Company’s general unsecured obligations that ranked senior in right of payment to all of the Company’s future indebtedness or other obligations that are expressly subordinated, or junior, in right of payment to the 2024 Notes; equal in right of payment to the Company’s existing and future indebtedness or other obligations that are not so subordinated or junior; effectively junior to any of the Company’s secured indebtedness or other obligations (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness; and structurally junior to all existing and future indebtedness and other obligations (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest and facility fees, average stated interest rates and average outstanding balances for the 2024 Notes were as follows:

2026 Notes: On February 24, 2021, the Company issued $400,000 in aggregate principal amount of unsecured notes (the “2026 Notes”) and on October 13, 2021, the Company issued an additional $200,000 aggregate principal amount of 2026 Notes under the same terms as the original issuance, other than the issue date and the issue price. As of both September 30, 2025 and September 30, 2024, outstanding aggregate principal amount of the 2026 Notes was $600,000. The 2026 Notes bear interest at a rate of 2.500% per year payable semiannually in arrears on February 24 and August 24 of each year, commencing on August 24, 2021. The 2026 Notes mature on August 24, 2026.

The 2026 Notes are the Company’s general unsecured obligations that rank senior in right of payment to all of the Company’s future indebtedness or other obligations that are expressly subordinated, or junior, in right of payment to the 2026 Notes; equal in right of payment to the Company’s existing and future indebtedness or other obligations that are not so subordinated or junior; effectively junior to any of the Company’s secured indebtedness or other obligations (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness; and structurally junior to all existing and future indebtedness and other obligations (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

At any time or from time to time, the Company could redeem some or all of the 2026 Notes at a redemption price equal to the greater of (1)100% of the principal amount of the 2026 Notes to be redeemed or (2) the sum of the present values of the remaining scheduled payments of principal and interest (exclusive of accrued and unpaid interest to the date of redemption) on the 2026 Notes to be redeemed through July 24, 2026 (the date falling one month prior to the maturity date of the 2026 Notes), discounted to the redemption date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) using the applicable Treasury Rate plus 30 basis points, plus, in each case, accrued and unpaid interest, if any, to, but excluding, the redemption date; provided, however, that if the Company redeems any 2026 Notes on or after July 24, 2026 (the date falling one month prior to the maturity date of the 2026 Notes), the redemption price for the 2026 Notes will be equal to 100% of the principal amount of the 2026 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the 2026 Notes.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest and facility fees, average stated interest rates and average outstanding balances for the 2026 Notes were as follows:

2027 Notes: On August 3, 2021, the Company issued $350,000 in aggregate principal amount of unsecured notes (the “2027 Notes”). As of both September 30, 2025 and September 30, 2024, outstanding aggregate principal amount of the 2027 Notes was $350,000. The 2027 Notes bear interest at a rate of 2.050% per year payable semi-annually in arrears on February 15 and August 15 of each year, commencing on February 15, 2022. The 2027 Notes mature on February 15, 2027.

The 2027 Notes are the Company’s general unsecured obligations that rank senior in right of payment to all of the Company’s future indebtedness or other obligations that are expressly subordinated, or junior, in right of payment to the 2027 Notes; equal in right of payment to the Company’s existing and future indebtedness or other obligations that are not so subordinated or junior; effectively junior to any of the Company’s secured indebtedness or other obligations (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness; and structurally junior to all existing and future indebtedness and other obligations (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

At any time or from time to time, the Company could redeem some or all of the 2027 Notes at a redemption price equal to the greater of (1)100% of the principal amount of the 2027 Notes to be redeemed or (2) the sum of the present values of the remaining scheduled payments of principal and interest (exclusive of accrued and unpaid interest to the date of redemption) on the 2027 Notes to be redeemed through January 15, 2027 (the date falling one month prior to the maturity date of the 2027 Notes), discounted to the redemption date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) using the applicable Treasury Rate plus 25 basis points, plus, in each case, accrued and unpaid interest, if any, to, but excluding, the redemption date; provided, however, that if the Company redeems any 2027 Notes on or after January 15, 2027 (the date falling one month prior to the maturity date of the 2027 Notes), the redemption price for the 2027 Notes will be equal to 100% of the principal amount of the 2027 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the 2027 Notes.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest and facility fees, average stated interest rates and average outstanding balances for the 2027 Notes were as follows:

2028 Notes: On December 5, 2023, the Company issued $450,000 in aggregate principal amount of unsecured notes (the “2028 Notes”) and on September 19, 2025, the Company issued an additional $250,000 in aggregate principal amount of 2028 Notes under the same terms as the original issuance, other than the issue date and issue price. As of September 30, 2025 and September 30, 2024, the outstanding aggregate principal amount of the 2028 Notes was $700,000 and $450,000, respectively. The 2028 Notes bear interest at a rate of 7.050% per year payable semi-annually in arrears on June 5 and December 5 of each year, commencing on June 5, 2024. The 2028 Notes mature on December 5, 2028.

The 2028 Notes are the Company’s general unsecured obligations that rank senior in right of payment to all of the Company’s future indebtedness or other obligations that are expressly subordinated, or junior, in right of payment to the 2028 Notes; equal in right of payment to the Company’s existing and future indebtedness or other obligations that are not so subordinated or junior; effectively junior to any of the Company’s secured indebtedness or other obligations (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness; and structurally junior to all existing and future indebtedness and other obligations (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

At any time or from time to time, the Company could redeem some or all of the 2028 Notes at a redemption price equal to the greater of (1)100% of the principal amount of the 2028 Notes to be redeemed or (2) the sum of the present values of the remaining scheduled payments of principal and interest thereon discounted to the redemption date on the 2028 Notes on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) using the applicable Treasury Rate plus 45 basis points less interest accrued to the date of redemption. If the Company redeems any 2028 Notes on or after November 5, 2028 (the date falling one month prior to the maturity date of the 2028 Notes), the redemption price for the 2028 Notes will be equal to 100% of the principal amount of the 2028 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the 2028 Notes.

On December 5, 2023, the Company entered into an interest rate swap on the 2028 Notes with SMBC as the counterparty. Under the terms of the agreement, the Company agreed to receive a fixed rate of 7.310% and pay SMBC a rate of one-month Term SOFR +3.327%. The interest rate swap is designated as an effective hedge accounting instrument. The notional amount of the swap is $225,000 and terminates on November 5, 2028. The carrying value of the 2028 Notes is inclusive of an adjustment for the change in fair value of an effective hedge accounting relationship. See Note 5 for additional information.

On April 11, 2024, the Company entered into an interest rate swap on the 2028 Notes pursuant to which the Company agreed to receive a fixed rate of 7.310% and pay a rate of one-month SOFR plus 2.835%. The interest rate swap is designated as an effective hedge accounting instrument. The notional amount of the swap is $225,000 and terminates on November 5, 2028. The carrying value of the 2028 Notes is inclusive of an adjustment for the change in fair value of an effective hedge accounting relationship. See Note 5 for additional information.

On September 19, 2025, the Company entered into an interest rate swap on the 2028 Notes pursuant to which the Company agreed to receive a fixed rate of 5.050% and pay a floating interest rate of SOFR plus 1.723%. The interest rate swap is designated as an effective hedge accounting instrument. The notional amount of the swap is $250,000 and terminates on December 5, 2028. The carrying value of the 2028 Notes is inclusive of an adjustment for the change in fair value of an effective hedge accounting relationship. See Note 5 for additional information.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest and facility fees, average stated interest rates and average outstanding balances for the 2028 Notes were as follows:

(1)Includes cash paid or received for contractual interest rate swaps, which may have different contractual settlement dates among the (i) fixed interest leg, (ii) floating interest leg and (iii) the 2028 Notes.

(2) The annualized average stated interest rate reflects the translation of the stated interest expense and borrowings in foreign currencies to U.S. dollars.

2029 Notes: On February 1, 2024, the Company issued $600,000 in aggregate principal amount of unsecured notes (the “2029 Notes”) and on December 3, 2024, the Company issued an additional $150,000 in aggregate principal amount of 2029 Notes under the same terms as the original issuance, other than the issue date and the issue price. As of September 30, 2025 and September 30, 2024, the outstanding aggregate principal amount of the 2029 Notes was $750,000 and $600,000, respectively. The 2029 Notes bear interest at a rate of 6.000% per year payable semi-annually in arrears on January 15 and July 15 of each year, commencing on July 15, 2024. The 2029 Notes mature on July 15, 2029.

The 2029 Notes are the Company’s general unsecured obligations that rank senior in right of payment to all of the Company’s future indebtedness or other obligations that are expressly subordinated, or junior, in right of payment to the 2029 Notes; equal in right of payment to the Company’s existing and future indebtedness or other obligations that are not so subordinated or junior; effectively junior to any of the Company’s secured indebtedness or other obligations (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness; and structurally junior to all existing and future indebtedness and other obligations (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

At any time or from time to time, the Company could redeem some or all of the 2029 Notes at a redemption price equal to the greater of (1)100% of the principal amount of the 2029 Notes to be redeemed or (2) the sum of the present values of the remaining scheduled payments of principal and interest thereon discounted to the redemption date on the 2029 Notes on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) using the applicable Treasury Rate plus 35 basis points less interest accrued to the date of redemption. If the Company redeems any 2029 Notes on or after June 15, 2029 (the date falling one month prior to the maturity date of the 2029 Notes), the redemption price for the 2029 Notes will be equal to 100% of the principal amount of the 2029 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the 2029 Notes.

On February 1, 2024 and December 3, 2024, the Company entered into interest rate swap agreements on the 2029 Notes with SMBC and Macquarie, respectively, as counterparties. Under the terms of the agreement with SMBC, the Company (i) receives a fixed rate of 6.248% and (ii) pays SMBC a rate of one-month Term SOFR +2.444% on the first $600,000 of 2029 Notes. Under the terms of the agreement with Macquarie, the Company (i) receives a fixed rate of 5.881% and (ii) pays Macquarie a floating interest rate of three-month Term SOFR +2.012% on the second $150,000 of the 2029 Notes. The Company designated these interest rate swap as effective hedge accounting instruments. The total notional amount of both swap agreements is $750,000 and both agreements terminate on June

15, 2029. The carrying value of the 2029 Notes is inclusive of an adjustment for the change in fair value of an effective hedge accounting relationship. See Note 5 for additional information.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest and facility fees, average stated interest rates and average outstanding balances for the 2029 Notes were as follows:

(1)Includes cash paid or received for contractual interest rate swaps, which may have different contractual settlement dates among the (i) fixed interest leg, (ii) floating interest leg and (iii) the 2029 Notes.

(2)The annualized average stated interest rate reflects the translation of the stated interest expense and borrowings in foreign currencies to U.S. dollars.

Adviser Revolver: The Company has entered into the Adviser Revolver with the Investment Adviser pursuant to which, as of September 30, 2025, the Company was permitted to borrow up to $300,000. On June 13, 2025, the Company amended the Adviser Revolver to, among other things, increase the borrowing capacity under the Adviser Revolver from$200,000 to$300,000, extend the maturity date to June 13, 2032, and amend the rate that interest accrues on each loan from the short-term applicable federal rate to the mid-term applicable federal rate. As of September 30, 2024, the Company was permitted to borrow up to$200,000. The Adviser Revolver bears an interest rate equal to the mid-term Applicable Federal Rate (“AFR”). As of September 30, 2025, the mid-term AFR in effect on the Adviser Revolver based on the last interest rate reset was 3.9%. As of September 30, 2025, the Company had $39,200 outstanding debt under the Adviser Revolver. As of September 30, 2024, the Company hadno outstanding debt under the Adviser Revolver.

For the years ended September 30, 2025, 2024 and 2023, the components of interest expense, cash paid for interest, average stated interest rates and average outstanding balances for the Adviser Revolver were as follows:

For the years ended September 30, 2025, 2024 and 2023, the average total debt outstanding was $4,892,712, $3,492,575 and $3,069,412, respectively.

For the years ended September 30, 2025 and September 30, 2024, the effective average interest rate, which includes amortization of debt financing costs, accretion of discounts and amortization of prem iums on notes issued, non-usage facility fees and the net contractual interest rate swap expense on the 2028 and 2029 Notes but excluding the net gain/(loss) related to the fair value hedges associated with the 2028 and 2029 Notes and interest rate swaps, onthe Company's total debt was 5.8% and 6.2%, respectively. For the year ended September 30, 2023, the effective average interest rate, which includes amortization of debt financing costs, accretion of discounts and amortization of prem iums on notes issued and non-usage facility fees, on the Company's total debt was 4.9%.

A summary of the Company’s maturity requirements for borrowings as of September 30, 2025 is as follows:

(1) Represents principal outstanding plus unamortized premium and / or unaccreted original issue discount.

(2) Carrying value is inclusive of an adjustment for the change in fair value of an effective hedge accounting relationship. See Note 5 for additional information.

Note 8. Federal Income Tax Matters

The Company has elected to be treated and intends to be subject to tax as a RIC under Subchapter M of the Code. As a result, the Company must distribute substantially all of its net taxable income each tax year as dividends to its stockholders which will generally relieve the Company from U.S. federal income tax.

Dividends from net investment income and distributions from net realized capital gains are determined in accordance with U.S. federal tax regulations, which could differ from amounts determined in accordance with GAAP and those differences could be material. These book-to-tax differences are either temporary or permanent in nature. Reclassifications due to permanent book-tax differences have no impact on net assets.

The following permanent differences were reclassified for tax purposes among the components of net assets for the years ended September 30, 2025, 2024 and 2023:

Taxable income generally differs from net increase (decrease) in net assets resulting from operations for financial reporting purposes due to temporary and permanent differences in the recognition of income and expenses and generally excludes unrealized appreciation (depreciation) on investment transactions as investment gains and losses are not included in taxable income until they are realized.

The following table reconciles net increase (decrease) in net assets resulting from operations to taxable income for the years ended September 30, 2025, 2024 and 2023:

The tax character of distributions paid during the years ended September 30, 2025, 2024 and 2023 was as follows:

The tax basis components of distributable earnings/(accumulated losses) and reconciliation to accumulated earnings/(deficit) on a book basis for the years ended September 30, 2025, 2024 and 2023 were as follows:

Capital losses in excess of capital gains earned in a tax year may generally be carried forward and used to offset capital gains, subject to certain limitations. Capital losses incurred by the Company in tax years beginning after September 30, 2011 are not subject to expiration and retain their character as either short-term or long-term capital losses. As of September 30, 2025, the Company estimates that it will have $53,950 of capital loss carryforward available for use in subsequent tax years, which is included in other temporary differences in the table above.

For tax purposes, the Company may elect to defer any portion of a post-October capital loss or late-year ordinary loss to the first day of the following fiscal year. As of September 30, 2025, the Company elected to defer $6,981 of ordinary losses. The Company did not elect to defer any short-term capital losses and long-term capital losses as of September 30, 2025. As of September 30, 2024 and September 30, 2023, the Company didnot elect to defer ordinary losses, short-term capital losses or long-term capital losses.

For the tax year ended September 30, 2025, the Company estimates that distributions were in excess of taxable income and does not expect to carry forward excess taxable income for distribution into 2026.

As of September 30, 2025, the federal tax cost of investments was $8,728,590 resulting in estimated gross unrealized gains and losses of $314,813 and $274,014, respectively.

The Company has consolidated subsidiaries that are subject to U.S. federal and state corporate-level income taxes. For the years ended September 30, 2025, 2024 and 2023, the Company recorded a net tax benefit for taxable subsidiaries of $563, $549 and $101, respectively. As of September 30, 2025, the Company recorded a net deferred tax liability of $217 for taxable subsidiaries, which is included in accounts payable and other liabilities on the Consolidated Statements of Financial Condition. The deferred tax liability primarily resulted from unrealized appreciation on the investments held at the taxable subsidiaries. As of September 30, 2024, the Company recorded a net deferred tax liability of $780 for taxable subsidiaries, which is included in accounts payable and other liabilities on the Consolidated Statements of Financial Condition. The deferred tax liability primarily resulted from unrealized appreciation on the investments held at the taxable subsidiaries.

Note 9. Commitments and Contingencies

Commitments: As of September 30, 2025, the Company had outstanding commitments to fund investments totaling $927,887, including $252,574 of commitments on undrawn revolvers. As of September 30, 2024, the Company had outstanding commitments to fund investments totaling $717,869, including $157,618 of commitments on undrawn revolvers.

Indemnifications: In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties that provide general indemnifications. The Company’s maximum exposure under these arrangements is unknown, as these involve future claims against the Company that have not occurred. The Company expects the risk of any future obligations under these indemnifications to be remote.

Off-balance sheet risk: Off-balance sheet risk refers to an unrecorded potential liability that could result in a future obligation or loss, even though it does not appear on the Consolidated Statements of Financial Condition. The Company has entered and, in the future, could again enter into derivative instruments that contain elements of off-balance sheet market and credit risk. Refer to Note 5 for outstanding forward currency contracts and interest rate swap agreements as of September 30, 2025 and September 30, 2024. Derivative instruments can be affected by market conditions, such as interest rate and foreign currency volatility, which could impact the fair value of the derivative instruments. If market conditions move against the Company, it could not achieve the anticipated benefits of the derivative instruments and could realize a loss. The Company minimizes market risk through monitoring its investments and borrowings.

Concentration of credit and counterparty risk: Credit risk arises primarily from the potential inability of counterparties to perform in accordance with the terms of the contract. The Company has engaged and, in the future, may engage again in derivative transactions with counterparties. In the event that the counterparties do not fulfill their obligations, the Company could be exposed to risk. The risk of default depends on the creditworthiness of the counterparties or issuers of the instruments. The Company’s maximum loss that it could incur related to counterparty risk on its derivative instruments is the value of the collateral for that respective derivative instrument. It is the Company’s policy to review, as necessary, the credit standing of each counterparty.

Legal proceedings: In the normal course of business, the Company is subject to legal and regulatory proceedings that are generally incidental to its ongoing operations. While there can be no assurance of the ultimate disposition of any such proceedings, the Company does not believe any disposition will have a material adverse effect on the Company’s consolidated financial statements.

Note 10. Financial Highlights

The financial highlights for the Company are as follows:

(1)Based on actual number of shares outstanding at the end of the corresponding period or the weighted average shares outstanding for the period, unless otherwise noted, as appropriate.

(2)Represents an amount less than $0.01.

(3)Net increase in net assets as a result of issuance of shares pursuant to the GBDC 3 Merger.

(4)Includes the impact of different share amounts as a result of calculating certain per share data based on weighted average shares outstanding during the period and certain per share data based on the shares outstanding at the end of the period and as of the dividend record date.

(5)Total return based on market value assumes distributions are reinvested in accordance with the DRIP. Total return does not include sales load.

(6)Total return based on average net asset value is calculated as (a) the net increase (decrease) in net assets resulting from operations divided by (b) the daily average of total net assets. Total return does not include sales load.

(7)Effective February 6, 2019, in accordance with Section 61(a)(2) of the 1940 Act, with certain limited exceptions, the Company is allowed to borrow amounts such that its asset coverage, as defined in the 1940 Act, is at least 150% after such borrowing (excluding the Company's SBA debentures pursuant to exemptive relief received by the Company from the SEC). Prior to February 6, 2019, in accordance with the 1940 Act, with certain limited exceptions, the Company was allowed to borrow amounts such that its asset coverage, as defined in the 1940 Act, was at least 200% after such borrowing (excluding the Company's SBA debentures pursuant to exemptive relief received by the Company from the SEC).

Note 11. Senior Securities

The following is information about the Company’s senior securities as of dates indicated in the table below:

(1)Total amount of each class of senior securities outstanding at the end of the period presented.

(2)Asset coverage per unit is the ratio of the carrying value of our total consolidated assets, less all liabilities and indebtedness not represented by senior securities, to the aggregate amount of senior securities representing indebtedness. Asset coverage per unit is expressed in terms of dollar amounts per $1,000 of indebtedness.

(3)The amount to which such class of senior security would be entitled upon the voluntary liquidation of the issuer in preference to any security junior to it. The “ — ” in this column indicates that the SEC expressly does not require this information to be disclosed for certain types of senior securities.

(4)Not applicable because such senior securities are not registered for public trading, with the exception of the 2024 Notes, the 2026 Notes, the 2027 Notes, the 2028 Notes and the 2029 Notes. The average market value per unit calculated for the 2024 Notes, the 2026 Notes, the 2027 Notes, the 2028 Notes and the 2029 Notes is based on the average monthly prices of such notes and is expressed per $1,000 of indebtedness.

(5)2010 Debt Securitization refers to the $350.0 million term debt securitization that was completed on July 16, 2010, and redeemed on July 20, 2018.

(6)2014 Debt Securitization refers to the $402.6 million term debt securitization that was completed on June 5, 2014, and redeemed on August 26, 2020.

(7)2018 Debt Securitization refers to the $327.0 million term debt securitization that was completed on November 16, 2018, and redeemed on November 18, 2024.

(8)Represents $546,500 of outstanding GCIC 2018 Notes, that was originally completed December 13, 2018 and we assumed on September 19, 2019, in connection with the GCIC Merger, less the unamortized discount recognized on the assumption of the GCIC 2018 Debt Securitization in the GCIC Merger and redeemed on November 18, 2024.

(9)2020 Debt Securitization refers to the $330.4 million term debt securitization that we completed on August 26, 2020, and redeemed on August 26, 2021.

(10)Represents $298,000 of outstanding GBDC 3 2021 Notes, that was originally completed March 11, 2021 and we assumed on June 3, 2024 in connection with the GBDC 3 Merger, less the unamortized discount recognized on the assumption of the GBDC 3 2021 Debt Securitization in the GBDC 3 Merger and redeemed on November 18, 2024.

(11)Represents $401,800 of outstanding GBDC 3 2022 Notes, that was originally completed January 25, 2022 and we assumed on June 3, 2024 in connection with the GBDC 3 Merger, less the unamortized discount recognized on the assumption of the GBDC 3 2022 Debt Securitization in the GBDC 3 Merger and redeemed on August 1, 2025.

(12)Represents $386,600 of outstanding GBDC 3 2022-2 Notes, that was originally completed December 14, 2022 and we assumed on June 3, 2024 in connection with the GBDC 3 Merger, less the unamortized discount recognized on the assumption of the GBDC 3 2022-2 Debt Securitization in the GBDC 3 Merger and redeemed on December 16, 2024.

(13)Credit Facility refers to the amended and restated senior secured revolving credit facility with Wells Fargo Bank, N.A, originally entered into on July 21, 2011 and terminated on February 4, 2019.

(14)MS Credit Facility refers to the amended senior secured credit facility with Morgan Stanley Bank N.A, originally entered into on July 20, 2018 and terminated on November 16, 2018.

(15)WF Credit Facility refers to the senior secured revolving credit facility with Wells Fargo N.A, originally entered into on October 10, 2014 and terminated on February 12, 2021.

(16)DB Credit Facility refers to the senior secured revolving credit facility with Deutsche Bank AG, New York Branch originally entered into on December 31, 2018 and terminated on October 9, 2020.

(17)As of September 30, 2021, represents $400,000 outstanding of 2024 Notes less the unamortized discount recognized upon origination. As of and subsequent to September 30, 2022, represents $500,000 outstanding of 2024 Notes less the unamortized net discount recognized upon origination.

(18)As of September 30, 2021, represents $400,000 outstanding of 2026 Notes less the unamortized discount recognized upon origination. As of and subsequent to September 30, 2022, represents $600,000 outstanding of 2026 Notes less the unamortized net discount recognized upon origination.

(19)Represents $350,000 outstanding of 2027 Notes less the unamortized discount recognized upon origination.

(20)As of September 30, 2024, represents $450,000 outstanding of the 2028 Notes less the unamortized discount recognized upon origination. As of September 30, 2025, represents $700,000 outstanding of 2028 Notes less the unamortized discount recognized upon origination and an adjustment for the change in fair value of an effective hedge accounting relationship.

(21)As of September 30, 2024, represents $600,000 outstanding of the 2028 Notes less the unamortized discount recognized upon origination. As of September 30, 2025, represents $750,000 outstanding of 2029 Notes less the unamortized discount recognized upon origination and an adjustment for the change in fair value of an effective hedge accounting relationship.

(22)These amounts exclude the SBA Debentures pursuant to exemptive relief we received from the SEC on September 13, 2011. There were no SBA Debentures outstanding as of and subsequent to September 30, 2021.

Note 12. Earnings Per Share

The following information sets forth the computation of the net increase in net assets per share resulting from operations for the years ended September 30, 2025, 2024 and 2023:

Note 13. Common Stock Transactions

On October 6, 2023, the Company entered into the 2023 Equity Distribution Agreement, which provides that the Company may, from time to time, issue and sell shares of its common stock, par value $0.001 per share, having an aggregate offering price of up to $288,043 in an “at the market offering,” as defined in Rule 415 under the Securities Act of 1933, as amended (the “ATM Program”).

For the year ended September 30, 2025, the Company issued common stock under the ATM Program as follows:

On August 1, 2025, the Board re-approved the Program to repurchase up to $150,000 of the Company’s common stock, exclusive of shares repurchased prior to the date of such authorization. Under the Program, purchases may be made at management’s discretion from time to time in open-market transactions, in accordance with all applicable securities laws and regulations. As of September 30, 2025, the repurchased shares have been retired and returned to the status of authorized but unissued shares of GBDC Common Stock.

For the year ended September 30, 2025, Wells Fargo Securities, LLC, as broker, had repurchased 2,900,808 shares of the Company’s common stock pursuant to the Program at an average price of $14.01 per share for an aggregate purchase price of approximately $40,631. As of September 30, 2025, the Company recorded a receivable for 200,000 shares repurchased at an average price of $13.74 per share for an aggregate purchase price of $2,748, which is included in other assets on the Consolidated Statements of Financial Condition.

For the year ended September 30, 2025, repurchases under the Program were as follows:

*The Program was re-approved on August 1, 2025 to purchase $150,000 of the Company’s common stock, exclusive of shares repurchased prior to the date of such authorization.

As of September 30, 2024, Wells Fargo Securities, LLC, as broker, had repurchased 331,928 shares of the Company’s common stock pursuant to the Program at an average price of $14.49 per share for an aggregate purchase price of approximately $4,809.

For the year ended September 30, 2024, repurchases under the Program were as follows:

*The Program was re-approved on August 2, 2024 to purchase $150,000 of the Company’s common stock, exclusive of shares repurchased prior to the date of such authorization.

On February 21, 2025, the Company filed an amendment to the Company’s certificate of incorporation to increase the number of authorized shares of capital stock of the Company from 351,000,000 shares to 501,000,000 shares, consisting of 500,000,000 shares of common stock, par value $0.001 per share, and 1,000,000 shares of preferred stock, par value $0.001 per share (the “Certificate of Incorporation Amendment”). The Certificate of Incorporation Amendment became effective immediately upon filing.

Note 14. Dividends and Distributions

The Company’s dividends and distributions are recorded on the ex-dividend date. The following table summarizes the Company’s dividend declarations and distributions during the years ended September 30, 2025, 2024 and 2023:

(1)In accordance with the Company's DRIP,162,709 shares of the Company's stock were purchased in the open market at an average price of $15.08 and were allocated to stockholders of the Company participating in DRIP.

(2)In accordance with the Company’s DRIP,130,168 shares of the Company’s stock were purchased in the open market at an average price of $15.08 and were allocated to stockholders of the Company participating in DRIP.

(3)In accordance with the Company's DRIP,1,094,965 shares of the Company's stock were purchased in the open market at an average price of $14.74 and were allocated to stockholders of the Company participating in DRIP.

(4)In accordance with the Company's DRIP,1,217,370 shares of the Company's stock were purchased in the open market at an average price of $13.68 and were allocated to stockholders of the Company participating in DRIP.

(5)In accordance with the Company's DRIP,339,804 shares of the Company's stock were purchased in the open market at an average price of $15.08 and were allocated to stockholders of the Company participating in DRIP.

(6)In accordance with the Company's DRIP,1,330,990 shares of the Company's stock were purchased in the open market at an average price of $15.10 and were allocated to stockholders of the Company participating in DRIP.

(7)In accordance with the Company's DRIP,689,422 shares of the Company's stock were purchased in the open market at an average price of $13.27 and were allocated to stockholders of the Company participating in DRIP.

(8)In accordance with the Company's DRIP,959,844 shares of the Company's stock were purchased in the open market at an average price of $13.39 and were allocated to stockholders of the Company participating in DRIP.

(9)In accordance with the Company's DRIP,854,808 shares of the Company's stock were purchased in the open market at an average price of $13.51 and were allocated to stockholders of the Company participating in DRIP.

(10)In accordance with the Company's DRIP,90,264 shares of the Company's stock were purchased in the open market at an average price of $14.28 and were allocated to stockholders of the Company participating in DRIP.

(11)In accordance with the Company's DRIP,824,353 shares of the Company's stock were purchased in the open market at an average price of $14.67 and were allocated to stockholders of the Company participating in DRIP.

Note 15. Acquisition of Golub Capital BDC 3, Inc.

On June 3, 2024, the Company completed its previously announced acquisition of GBDC 3. In accordance with the terms of the GBDC 3 Merger Agreement, at the effective time of the GBDC 3 Merger, each outstanding share of GBDC 3 common stock was converted into the right to receive 0.9138 shares of common stock, par value $0.001 per share of the Company (with GBDC 3 stockholders receiving cash in lieu of fractional shares of the Company’s common stock). As a result of the GBDC 3 Merger, the Company issued an aggregate of 92,115,308 shares of its common stock to former GBDC 3 stockholders.

The GBDC 3 Merger was accounted for in accordance with the asset acquisition method of accounting as detailed in ASC Topic 805. The fair value of the merger consideration paid and transaction costs incurred to complete the GBDC 3 Merger by the Company was allocated to the assets acquired and liabilities assumed, based on their relative fair values as of the date of acquisition and did not give rise to goodwill. The excess of merger consideration paid over the fair value of net assets acquired is considered the purchase premium. Immediately following the acquisition of GBDC 3, the Company recorded its assets at their respective fair values and, as a result, the purchase premium allocated to the cost basis of the GBDC 3 assets acquired was immediately recognized as unrealized depreciation on the Company's Consolidated Statement of Operations. The purchase premium allocated to investments in loan securities will amortize over the life of the loans through interest income with a corresponding reversal of the unrealized depreciation on the GBDC 3 loans acquired through their ultimate disposition. The purchase premium allocated to investments in equity securities, will not amortize over the life of the equity securities through interest income and, assuming no subsequent change to the fair value of the GBDC 3 equity securities acquired and disposition of such equity securities at fair value, the Company will recognize a realized loss or a reduction in realized gains with a corresponding reversal of the unrealized depreciation upon disposition of the GBDC 3 equity securities acquired.

The merger was considered a tax-free reorganization and the Company has elected to carry forward the historical cost basis of the GBDC 3 investments for tax purposes. The following table summarizes the allocation of the purchase price to the assets acquired and liabilities assumed as a result of the GBDC 3 Merger:

(1)Based on the most recent market price at closing of $16.57 and the 92,115,308 shares of common stock issued by the Company in conjunction with the GBDC 3 Merger.

(2)Includes $46,067 of restricted cash and cash equivalents, $373 of foreign restricted cash and cash equivalents and $1,064 of foreign cash and cash equivalents.

(3)Includes $4,651 of management fees and $4,271 of incentive fees accrued by GBDC 3 through the closing date of the GBDC 3 Merger pursuant to an investment advisory agreement between GBDC 3 and the Investment Adviser, which was terminated upon the closing of the GBDC 3 Merger. The payable for these fees was assumed by the Company and paid by the Company to the Investment Adviser in July 2024.

Note 16. Subsequent Events

In preparing these consolidated financial statements, the Company has evaluated events and transactions for potential recognition or disclosure through the date of issuance. There are no subsequent events to disclose except for the following:

On November 14, 2025, the Company’s Board declared a quarterly distribution of $0.39 per share payable on December 30, 2025 to holders of record as of December 12, 2025.

For the period of October 1, 2025 through November 18, 2025, Wells Fargo Securities, LLC, as broker, has repurchased 2,540,542 shares of the Company’s common stock pursuant to the Program (as defined in Note 2) for an aggregate purchase price of approximately $34,792 at an average price of $13.69 per share.