MSC INCOME FUND INC

Notes to the Consolidated Financial Statements

NOTE A—ORGANIZATION AND BASIS OF PRESENTATION

1. Organization

MSC Income Fund, Inc. (“MSIF” or, together with its consolidated subsidiaries, “MSC Income Fund” or the “Company”) is a principal investment firm primarily focused on providing debt capital to middle market (“Middle Market”) companies and customized debt and equity financing to lower middle market (“LMM”) companies. MSC Income Fund’s portfolio investments are typically made to support leveraged buyouts, recapitalizations, growth financings, refinancings and acquisitions of companies that operate in a variety of industry sectors. MSC Income Fund seeks to partner with private equity funds in its Private Loan (as defined below) and Middle Market investment strategies. MSC Income Fund invests primarily in secured debt investments of Middle Market companies generally headquartered in the United States and in secured debt investments, equity investments, warrants and other securities of LMM companies based in the United States. MSC Income Fund seeks to partner with entrepreneurs, business owners and management teams and generally provides “one-stop” financing alternatives within its LMM investment strategy.

MSIF was formed in November 2011 to operate as an externally managed business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). MSIF has elected to be treated for U.S. federal income tax purposes as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). As a result, MSIF generally does not pay corporate-level U.S. federal income taxes on any net ordinary taxable income or capital gains that it distributes to its stockholders.

On October 28, 2020, MSIF’s stockholders approved the appointment of MSC Adviser I, LLC (the “Adviser”), which is wholly-owned by Main Street Capital Corporation (“Main Street”), a New York Stock Exchange listed BDC, as MSIF’s investment adviser and administrator under an Investment Advisory and Administrative Services Agreement dated October 30, 2020 (the “Investment Advisory Agreement”). In such role, the Adviser has the responsibility to manage the business of MSC Income Fund, including the responsibility to identify, evaluate, negotiate and structure prospective investments, make investment and portfolio management decisions, monitor MSC Income Fund’s investment portfolio and provide ongoing administrative services.

MSIF has certain direct and indirect wholly-owned subsidiaries that have elected to be taxable entities (the “Taxable Subsidiaries”). The primary purpose of the Taxable Subsidiaries is to permit MSIF to hold equity investments in portfolio companies which are “pass-through” entities for tax purposes. MSIF also has certain direct and indirect wholly-owned subsidiaries formed for financing purposes (the “Structured Subsidiaries”).

Unless otherwise noted or the context otherwise indicates, the terms “we,” “us,” “our,” the “Company” and “MSC Income Fund” refer to MSIF and its consolidated subsidiaries, which include the Taxable Subsidiaries and the Structured Subsidiaries.

2. Basis of Presentation

MSC Income Fund’s consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The Company is an investment company following accounting and reporting guidance in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 946, Financial Services—Investment Companies (“ASC 946”). For each of the periods presented herein, MSC Income Fund’s consolidated financial statements include the accounts of MSIF and its consolidated subsidiaries. The Investment Portfolio, as used herein, refers to all of MSC Income Fund’s investments in Private Loan portfolio companies, investments in LMM portfolio companies, investments in Middle Market portfolio companies and Other Portfolio investments (see Note C — Fair Value Hierarchy for Investments — Portfolio Composition — Investment Portfolio Compositionfor additional discussion of MSC Income Fund’s Investment Portfolio and definitions for the defined terms Private Loan and Other Portfolio). MSC Income Fund’s results of operations and cash flows for the years ended December 31, 2023, 2022 and 2021 and financial position as of December 31, 2023 and 2022, are presented on a consolidated basis. The effects of all intercompany transactions between MSIF and its consolidated subsidiaries have been eliminated in consolidation.

Principles of Consolidation

Under ASC 946, MSC Income Fund is precluded from consolidating other entities in which MSC Income Fund has equity investments, including those in which it has a controlling interest, unless the other entity is another investment company. An exception to this general principle in ASC 946 occurs if MSC Income Fund holds a controlling interest in an operating company that provides all or substantially all of its services directly to MSC Income Fund. Accordingly, as noted above, MSC Income Fund’s consolidated financial statements include the financial position and operating results for the Taxable Subsidiaries and the Structured Subsidiaries. MSC Income Fund has determined that none of its portfolio investments qualify for this exception. Therefore, MSC Income Fund’s Investment Portfolio is carried on the Consolidated Balance Sheets at fair value, as discussed further in Note B.1. — Summary of Significant Accounting Policies — Valuation of the Investment Portfolio, with any adjustments to fair value recognized as “Net Unrealized Appreciation (Depreciation)” until the investment is realized, usually upon exit, resulting in any gain or loss being recognized as a “Net Realized Gain (Loss),” in both cases on the Consolidated Statements of Operations.

Portfolio Investment Classification

MSC Income Fund classifies its Investment Portfolio in accordance with the requirements of the 1940 Act. Under the 1940 Act, (a) “Control Investments” are defined as investments in which MSC Income Fund owns more than 25% of the voting securities or has rights to maintain greater than 50% of the board representation, (b) “Affiliate Investments” are defined as investments in which MSC Income Fund owns between 5% and 25% (inclusive) of the voting securities and does not have rights to maintain greater than 50% of the board representation and (c) “Non-Control/Non-Affiliate Investments” are defined as investments that are neither Control Investments nor Affiliate Investments. For purposes of determining the classification of its Investment Portfolio, MSC Income Fund has excluded consideration of any voting securities or board appointment rights held by Main Street and third-party investment funds advised by the Adviser.

NOTE B—SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

1. Valuation of the Investment Portfolio

MSC Income Fund accounts for its Investment Portfolio at fair value. As a result, MSC Income Fund follows the provisions of ASC 820, Fair Value Measurements and Disclosures (“ASC 820”). ASC 820 defines fair value, establishes a framework for measuring fair value, establishes a fair value hierarchy based on the quality of inputs used to measure fair value and enhances disclosure requirements for fair value measurements. ASC 820 requires MSC Income Fund to assume that the portfolio investment is to be sold in the principal market to independent market participants, which may be a hypothetical market. Market participants are defined as buyers and sellers in the principal market that are independent, knowledgeable and willing and able to transact.

MSC Income Fund’s portfolio strategy calls for it to invest primarily in debt securities issued by Middle Market companies and illiquid debt and equity securities issued by privately held, LMM companies. The Middle Market companies in which MSC Income Fund invests are generally larger in size than the LMM companies and their debt securities can be more liquid than the debt securities issued by LMM companies. MSC Income Fund categorizes some of its investments in Middle Market companies and LMM companies as Private Loan portfolio investments, which are primarily debt securities in privately held companies that have primarily been originated directly by our Adviser or, to a lesser extent, through our Adviser’s strategic relationships with other investment funds on a collaborative basis through investments that are often referred to in the debt markets as “club deals” because of the small lender group size. In both cases, MSC Income Fund’s Private Loan investments are typically made to support a company owned by or in the process of being acquired by a private equity sponsor. Private Loan investments are made in companies that are generally consistent with the size of companies MSC Income Fund invests in through its Middle Market portfolio and LMM portfolio. MSC Income Fund’s portfolio also includes Other Portfolio investments which primarily consist of investments that are not consistent with the typical profiles for its Private Loan, LMM or Middle Market portfolio investments, including investments which may be managed by third parties. MSC Income Fund’s portfolio investments may be subject to restrictions on resale.

Private Loan investments may include investments which have no established market or have established markets that are not active, while LMM investments and Other Portfolio investments generally have no established trading market. Middle Market portfolio investments generally have established markets that are not active. MSC Income Fund determines in good faith the fair value of its Investment Portfolio pursuant to a valuation policy in accordance with ASC 820, with such valuation process approved by its Board of Directors and in accordance with the 1940 Act. MSC Income Fund’s valuation policies and processes are intended to provide a consistent basis for determining the fair value of MSC Income Fund’s Investment Portfolio.

For Private Loan and Middle Market portfolio investments in debt securities for which it has determined that third-party quotes or other independent pricing are not available or appropriate, MSC Income Fund generally estimates the fair value based on the assumptions that it believes hypothetical market participants would use to value the investment in a current hypothetical sale using the yield-to-maturity model (“Yield-to-Maturity”) valuation method. For LMM portfolio investments, MSC Income Fund generally reviews external events, including private mergers, sales and acquisitions involving comparable companies, and includes these events in the valuation process by using an enterprise value waterfall methodology (“Waterfall”) for its LMM equity investments and an income approach using a Yield-to-Maturity valuation method for its LMM debt investments. For Middle Market portfolio investments in debt securities for which it has determined that third-party quotes or other independent prices are available, MSC Income Fund primarily uses quoted prices in the valuation process. MSC Income Fund determines the appropriateness of the use of third-party broker quotes, if any, in determining fair value based on its understanding of the level of actual transactions used by the broker to develop the quote and whether the quote was an indicative price or binding offer, the depth and consistency of broker quotes and the correlation of changes in broker quotes with underlying performance of the portfolio company and other market indices. For its Other Portfolio equity investments, MSC Income Fund generally calculates the fair value of the investment primarily based on the net asset value (“NAV”) of the fund and adjusts the fair value for other factors deemed relevant that would affect the fair value of the investment. All of the valuation approaches for MSC Income Fund’s portfolio investments estimate the value of the investment as if MSC Income Fund was to sell, or exit, the investment as of the measurement date.

These valuation approaches consider the value associated with MSC Income Fund’s ability to control the capital structure of the portfolio company, as well as the timing of a potential exit. For valuation purposes, “control” portfolio investments are composed of debt and equity securities in companies for which MSC Income Fund has a controlling interest in the equity ownership of the portfolio company or the ability to nominate a majority of the portfolio company’s board of directors. For valuation purposes, “non-control” portfolio investments are generally composed of debt and equity securities in companies for which MSC Income Fund does not have a controlling interest in the equity ownership of the portfolio company or the ability to nominate a majority of the portfolio company’s board of directors.

Under the Waterfall valuation method, MSC Income Fund estimates the enterprise value of a portfolio company using a combination of market and income approaches or other appropriate valuation methods, such as considering recent transactions in the equity securities of the portfolio company or third-party valuations of the portfolio company, and then performs a Waterfall calculation by allocating the enterprise value over the portfolio company’s securities in order of their preference relative to one another. The enterprise value is the fair value at which an enterprise could be sold in a transaction between two willing parties, other than through a forced or liquidation sale. Typically, privately held companies are bought and sold based on multiples of earnings before interest, taxes, depreciation and amortization (“EBITDA”), cash flows, net income, revenues, or in limited cases, book value. There is no single methodology for estimating enterprise value. For any one portfolio company, enterprise value is generally described as a range of values from which a single estimate of enterprise value is derived. In estimating the enterprise value of a portfolio company, MSC Income Fund analyzes various factors including the portfolio company’s historical and projected financial results. Due to SEC deadlines for MSC Income Fund’s quarterly and annual financial reporting, the operating results of a portfolio company used in the current period valuation are generally the results from the period ended three months prior to such valuation date and may include unaudited, projected, budgeted or pro forma financial information and may require adjustments for non-recurring items or to normalize the operating results that may require significant judgment in determining. In addition, projecting future financial results requires significant judgment regarding future growth assumptions. In evaluating the operating results, MSC Income Fund also analyzes the impact of exposure to litigation, loss of customers or other contingencies. After determining the appropriate enterprise value, MSC Income Fund allocates the enterprise value to investments in order of the legal priority of the various components of the portfolio company’s capital structure. In applying the Waterfall valuation method, MSC Income Fund assumes the loans are paid-off at the principal amount in a change in control transaction and are not assumed by the buyer, which MSC Income Fund believes is consistent with its past transaction history and standard industry practices.

Under the Yield-to-Maturity valuation method, MSC Income Fund also uses the income approach to determine the fair value of debt securities based on projections of the discounted future free cash flows that the debt security will likely generate, including analyzing the discounted cash flows of interest and principal amounts for the debt security, as set forth in the associated loan agreements, as well as the financial position and credit risk of the portfolio company. MSC Income Fund’s estimate of the expected repayment date of its debt securities is generally the maturity date of the instrument, as MSC Income Fund generally intends to hold its loans and debt securities to maturity. The Yield-to-Maturity analysis also considers changes in leverage levels, credit quality, portfolio company performance, changes in market-based interest rates and other factors. MSC Income Fund will generally use the value determined by the Yield-to-Maturity analysis as the fair value for that security; however, because of MSC Income Fund’s general intent to hold its loans to maturity, the fair value will not exceed the principal amount of the debt security valued using the Yield-to-Maturity valuation method. A change in the assumptions that MSC Income Fund uses to estimate the fair value of its debt securities using the Yield-to-Maturity valuation method could have a material impact on the determination of fair value. If there is deterioration in credit quality or if a debt security is in workout status, MSC Income Fund may consider other factors in determining the fair value of the debt security, including the value attributable to the debt security from the enterprise value of the portfolio company or the proceeds that would most likely be received in a liquidation analysis.

Under the NAV valuation method, for an investment in an investment fund that does not have a readily determinable fair value, MSC Income Fund measures the fair value of the investment predominately based on the NAV of the investment fund as of the measurement date and adjusts the investment’s fair value for factors known to MSC Income Fund that would affect that fund’s NAV, including, but not limited to, fair values for individual investments held by the fund if MSC Income Fund holds the same investment or for a publicly traded investment. In addition, in determining the fair value of the investment, MSC Income Fund considers whether adjustments to the NAV are necessary in certain circumstances, based on the analysis of any restrictions on redemption of MSC Income Fund’s investment as of the measurement date, recent actual sales or redemptions of interests in the investment fund, and expected future cash flows available to equity holders, including the rate of return on those cash flows compared to an implied market return on equity required by market participants, or other uncertainties surrounding MSC Income Fund’s ability to realize the full NAV of its interests in the investment fund.

Pursuant to its internal valuation process and the requirements under the 1940 Act, MSC Income Fund performs valuation procedures on each of its portfolio investments quarterly. In addition to its internal valuation process, in arriving at estimates of fair value for its investments in its Private Loan portfolio companies, MSC Income Fund, among other things, consults with a nationally recognized independent financial advisory services firm (the “Financial Advisory Firm”). The Financial Advisory Firm analyzes and provides observations and recommendations and an assurance certification regarding MSC Income Fund’s determinations of the fair value of its Private Loan portfolio company investments. The Financial Advisory Firm is generally consulted relative to MSC Income Fund’s investments in each Private Loan portfolio company at least once every calendar year, and for MSC Income Fund’s investments in new Private Loan portfolio companies, at least once in thetwelve-month period subsequent to the initial investment. In certain instances, MSC Income Fund may determine that it is not cost-effective, and as a result is not in its stockholders’ best interest, to consult with the Financial Advisory Firm on its investments in one or more Private Loan portfolio companies. Such instances include, but are not limited to, situations where the fair value of MSC Income Fund’s investment in a Private Loan portfolio company is determined to be insignificant relative to the total Investment Portfolio. MSC Income Fund consulted with and received an assurance certification from the Financial Advisory Firm in arriving at its determination of fair value for its investments in a total of 55 and 51 Private Loan portfolio companies during the years ended December 31, 2023 and 2022, respectively, representing 79% and 83% of the total Private Loan portfolio at fair value as of December 31, 2023 and 2022, respectively. Excluding its investments in Private Loan portfolio companies that, as of December 31, 2023 and 2022, as applicable, had not been in the Investment Portfolio for at least twelve months subsequent to the initial investment and its investments in Private Loan portfolio companies that were not reviewed because the investment is valued based upon third-party quotes or other independent pricing,90% and 94% of the Private Loan portfolio at fair value was reviewed and certified by the Financial Advisory Firm for the years ended December 31, 2023 and 2022, respectively.

For valuation purposes, all of MSC Income Fund’s Private Loan portfolio investments are either non-control or affiliate investments. For Private Loan portfolio investments for which it has determined that third-party quotes or other independent pricing are not available or appropriate, MSC Income Fund generally estimates the fair value based on the assumptions that it believes hypothetical market participants would use to value such Private Loan debt investments in a current hypothetical sale using the Yield-to-Maturity valuation method and such Private Loan equity investments in a current hypothetical sale using the Waterfall valuation method.

In addition to its internal valuation process, in arriving at estimates of fair value for its investments in its LMM portfolio companies, MSC Income Fund, among other things, consults with the Financial Advisory Firm. The Financial Advisory Firm analyzes and provides observations, recommendations and an assurance certification regarding MSC Income Fund’s determinations of the fair value of its LMM portfolio company investments. The Financial Advisory Firm is generally consulted relative to MSC Income Fund’s investments in each LMM portfolio company at least once every calendar year, and for MSC Income Fund’s investments in new LMM portfolio companies, at least once in thetwelve-month period subsequent to the initial investment. In certain instances, MSC Income Fund may determine that it is not cost-effective, and as a result is not in its stockholders’ best interest, to consult with the Financial Advisory Firm on its investments in one or more LMM portfolio companies. Such instances include, but are not limited to, situations where the fair value of MSC Income Fund’s investment in a LMM portfolio company is determined to be insignificant relative to the total Investment Portfolio. MSC Income Fund consulted with and received an assurance certification from the Financial Advisory Firm in arriving at MSC Income Fund’s determination of fair value for its investments in a total of 46 and 44 LMM portfolio companies during the years ended December 31, 2023 and 2022, respectively, representing 95% and 97% of the total LMM portfolio at fair value as of December 31, 2023 and 2022, respectively. Excluding its investments in LMM portfolio companies that, as of December 31, 2023 and 2022, as applicable, had not been in the Investment Portfolio for at least twelve months subsequent to the initial investment or whose primary purpose is to own real estate for which a third-party appraisal is obtained on at least an annual basis, over 99% of the LMM portfolio at fair value was reviewed and certified by the Financial Advisory Firm for both of the years ended December 31, 2023 and December 31, 2022.

For valuation purposes, all of MSC Income Fund’s Middle Market portfolio investments are non-control investments. To the extent sufficient observable inputs are available to determine fair value, MSC Income Fund uses observable inputs to determine the fair value of these investments through obtaining third-party quotes or other independent pricing. For Middle Market portfolio investments for which it has determined that third-party quotes or other independent pricing are not available or appropriate, MSC Income Fund generally estimates the fair value based on the assumptions that it believes hypothetical market participants would use to value such Middle Market debt investments in a current hypothetical sale using the Yield-to-Maturity valuation method and such Middle Market equity investments in a current hypothetical sale using the Waterfall valuation method. MSC Income Fund generally consults on a limited basis with the Financial Advisory Firm in connection with determining the fair value of its Middle Market portfolio investments due to the nature of these investments. The vast majority (97% and 91% as of December 31, 2023 and 2022, respectively) of the Middle Market portfolio investments (i) are valued using third-party quotes or other independent pricing services or (ii) MSC Income Fund has consulted with and received an assurance certification from the Financial Advisory Firm within the last twelve months.

For valuation purposes, all of MSC Income Fund’s Other Portfolio investments are non-control, affiliate or control investments. MSC Income Fund’s Other Portfolio investments comprised 2.3% and 2.7% of MSC Income Fund’s Investment Portfolio at fair value as of December 31, 2023 and 2022, respectively. Similar to the LMM investment portfolio, market quotations for Other Portfolio equity investments are generally not readily available. For its Other Portfolio equity investments, MSC Income Fund generally determines the fair value of these investments using the NAV valuation method.

Due to the inherent uncertainty in the valuation process, MSC Income Fund’s determination of fair value for its Investment Portfolio may differ materially from the values that would have been determined had a ready market for the securities existed. In addition, changes in the market environment, portfolio company performance and other events that may occur over the lives of the investments may cause the gains or losses ultimately realized on these investments to be materially different than the valuations currently assigned. MSC Income Fund determines the fair value of each individual investment and records changes in fair value as unrealized appreciation or depreciation.

MSC Income Fund uses an internally developed portfolio investment rating system in connection with its investment oversight, portfolio management and analysis and investment valuation procedures for its Private Loan, LMM and Middle Market portfolio companies. This system takes into account both quantitative and qualitative factors of each Private Loan, LMM and Middle Market portfolio company.

Rule 2a-5 under the 1940 Act permits a BDC’s board of directors to designate its executive officers or investment adviser as a valuation designee to determine the fair value for its investment portfolio, subject to the active oversight of the board. MSC Income Fund’s Board of Directors has approved policies and procedures pursuant to Rule 2a-5 (the “Valuation Procedures”) and has designated the Adviser, led by a group of Main Street’s and the Adviser’s executive officers, to serve as the Board of Directors’ valuation designee. MSC Income Fund believes its Investment Portfolio as of December 31, 2023 and 2022 approximates fair value as of those dates based on the markets in which it operates and other conditions in existence on those reporting dates.

2. Use of Estimates

The preparation of financial statements in conformity with U.S. 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 financial statements and the reported amounts of revenue and expenses during the period. Actual results may differ from these estimates under different conditions or assumptions. Additionally, as explained in Note B.1. — Summary of Significant Accounting Policies — Valuation of the Investment Portfolio, the consolidated financial statements include investments in the Investment Portfolio whose values have been estimated by MSC Income Fund pursuant to valuation policies and procedures approved and overseen by MSC Income Fund’s Board of Directors, in the absence of readily ascertainable market values. Because of the inherent uncertainty of the Investment Portfolio valuations, those estimated values may differ materially from the values that would have been determined had a ready market for the securities existed.

Macroeconomic factors, including pandemics, risk of recession, inflation, supply chain constraints or disruptions, geopolitical disruptions and changing market index interest rates, and the related effect on the U.S. and global economies, have impacted, and may continue to impact, the businesses and operating results of certain of MSC Income Fund’s portfolio companies. As a result of these and other current effects of macroeconomic factors, as well as the uncertainty regarding the extent and duration of their impact, the valuation of MSC Income Fund’s Investment Portfolio has and may continue to experience increased volatility.

3. Cash and Cash Equivalents

Cash and cash equivalents consist of cash and highly liquid investments with an original maturity of three months or less at the date of purchase. Cash and cash equivalents are carried at cost, which approximates fair value. At December 31, 2023, the Company had $20.8 million of cash equivalents invested in AAA-rated money market funds. These highly liquid, short-term investments are included in the Consolidated Schedule of Investments.

At December 31, 2023 and December 31, 2022, cash balances totaling $9.0 million and $11.7 million, respectively, exceeded Federal Deposit Insurance Corporation insurance protection levels, subjecting the Company to risk related to the uninsured balance.

4. Interest, Dividend and Fee Income

MSC Income Fund records interest and dividend income on the accrual basis to the extent amounts are expected to be collected. Dividend income is recorded when dividends are declared by the portfolio company or at such other time that an obligation exists for the portfolio company to make a distribution. MSC Income Fund evaluates accrued interest and dividend income periodically for collectability. When a loan or debt security becomes 90 days or more past due, and if MSC Income Fund otherwise does not expect the debtor to be able to service its debt obligation, MSC Income Fund will generally place the loan or debt security on non-accrual status and cease recognizing interest income on that loan or debt security until the borrower has demonstrated the ability and intent to pay contractual amounts due. If a loan or debt security’s status significantly improves regarding the debtor’s ability to service the debt obligation, or if a loan or debt security is sold or written off, MSC Income Fund removes it from non-accrual status.

As of December 31, 2023, investments on non-accrual status comprised 1.1% of MSC Income Fund’s total Investment Portfolio at fair value and 4.0% at cost. As of December 31, 2022, investments on non-accrual status comprised 0.8% of MSC Income Fund’s total Investment Portfolio at fair value and 4.8% at cost.

Interest income from investments in the “equity” class of security of collateralized loan obligation (“CLO”) funds (typically subordinated notes) is recorded based upon an estimation of an effective yield to expected maturity utilizing estimated projected cash flows in accordance with ASC 325-40, Beneficial Interests in Securitized Financial Assets. MSC Income Fund monitors the expected cash inflows from its investment in a CLO, including the expected residual payments, and the effective yield is determined and updated periodically.

MSC Income Fund holds certain debt and preferred equity instruments in its Investment Portfolio that contain payment-in-kind (“PIK”) interest and cumulative dividend provisions. The PIK interest, computed at the contractual rate specified in each debt agreement, is periodically added to the principal balance of the debt and is recorded as interest income. Thus, the actual collection of this interest may be deferred until the time of debt principal repayment. Cumulative dividends are recorded as dividend income, and any dividends in arrears are added to the balance of the preferred equity investment. The actual collection of these dividends in arrears may be deferred until such time as the preferred equity is redeemed or sold. To maintain RIC tax treatment (as discussed in Note B.7. — Summary of Significant Accounting Policies — Income Taxes below), these non-cash sources of income may need to be paid out to stockholders in the form of distributions, even though MSC Income Fund may not have collected the PIK interest and cumulative dividends in cash. MSC Income Fund stops accruing PIK interest and cumulative dividends and writes off any accrued and uncollected interest and dividends in arrears when it determines that such PIK interest and dividends in arrears are no longer collectible. For the years ended December 31, 2023, 2022 and 2021, (i)3.8%,2.5% and 2.3%, respectively, of MSC Income Fund’s total investment income was attributable to PIK interest income not paid currently in cash and (ii)0.1%,0.6% and 0.3%, respectively, of MSC Income Fund’s total investment income was attributable to cumulative dividend income not paid currently in cash.

MSC Income Fund may periodically provide services, including structuring and advisory services, to its portfolio companies or other third parties. For services that are separately identifiable and evidence exists to substantiate fair value, fee income is recognized as earned. Fees received in connection with debt financing transactions are generally deferred and accreted into income over the life of the financing.

A presentation of total investment income MSC Income Fund received from its Investment Portfolio in each of the periods presented is as follows:

5. Deferred Financing Costs

Deferred financing costs include commitment fees and other direct costs incurred in connection with arranging MSC Income Fund’s borrowings. These costs were incurred in connection with MSC Income Fund’s multi-year revolving Credit Facilities (as defined below in Note E — Debt) and have been capitalized as an asset and reflected in the Consolidated Balance Sheets as Deferred financing costs. Deferred financing costs incurred in connection with the Series A Notes (as defined below in Note E — Debt) are a direct deduction from the principal amount outstanding.

6. Unearned Income — Debt Origination Fees and Original Issue Discount and Discounts / Premiums to Par Value

MSC Income Fund capitalizes debt origination fees received in connection with financings and reflects such fees as unearned income netted against the applicable debt investments. The unearned income from the fees is accreted into income over the life of the financing.

In connection with its portfolio debt investments, MSC Income Fund sometimes receives nominal cost warrants or warrants with an exercise price below the fair value of the underlying equity (together, “nominal cost equity”) that are valued as part of the negotiation process with the particular portfolio company. When MSC Income Fund receives nominal cost equity, it allocates its cost basis in its investment between its debt security and its nominal cost equity at the time of origination based on amounts negotiated with the particular portfolio company. The allocated amounts are based upon the fair value of the nominal cost equity, which is then used to determine the allocation of cost to the debt security. Any discount recorded on a debt investment resulting from this allocation is reflected as unearned income, which is netted against the applicable debt investment, and accreted into interest income over the life of the debt investment. The actual collection of this interest is deferred until the time of debt principal repayment.

MSC Income Fund may also purchase debt securities at a discount or at a premium to the par value of the debt security. In the case of a purchase at a discount, MSC Income Fund records the investment at the par value of the debt security net of the discount, and the discount is accreted into interest income over the life of the debt investment. In the case of a purchase at a premium, MSC Income Fund records the investment at the par value of the debt security plus the premium, and the premium is amortized as a reduction to interest income over the life of the debt investment.

To maintain RIC tax treatment (as discussed in Note B.7. — Summary of Significant Accounting Policies — Income Taxes below), these non-cash sources of income may need to be paid out to stockholders in the form of distributions, even though MSC Income Fund may not have collected the interest income. For the years ended December 31, 2023, 2022 and 2021,2.5%,2.5%, and 5.7%, respectively, of MSC Income Fund’s total investment income was attributable to interest income from the accretion of discounts associated with debt investments, net of any premium amortization.

7. Income Taxes

MSIF has elected to be treated for U.S. federal income tax purposes as a RIC. MSIF’s taxable income includes the taxable income generated by MSIF and certain of its subsidiaries, including the Structured Subsidiaries, which are treated as disregarded entities for tax purposes. As a RIC, MSIF generally will not pay corporate-level U.S. federal income taxes on any net ordinary taxable income or capital gains that MSIF distributes to its stockholders. MSIF must generally distribute at least 90% of its “investment company taxable income” (which is generally its net ordinary taxable income and realized net short-term capital gains in excess of realized net long-term capital losses) and 90% of its tax-exempt income to maintain its RIC status (pass-through tax treatment for amounts distributed). As part of maintaining RIC status, undistributed taxable income (subject to a 4% non-deductible U.S. federal excise tax) pertaining to a given fiscal year may be distributed up to twelve months subsequent to the end of that fiscal year, provided such dividends are declared on or prior to the later of (i) the filing of the U.S. federal income tax return for the applicable fiscal year or (ii) the fifteenth day of the ninth month following the close of the year in which such taxable income was generated.

The Taxable Subsidiaries primarily hold certain equity investments for MSC Income Fund. The Taxable Subsidiaries permit MSC Income Fund to hold equity investments in portfolio companies which are “pass-through” entities for tax purposes and to continue to comply with the “source-of-income” requirements contained in the RIC tax provisions of the Code. The Taxable Subsidiaries are consolidated with MSC Income Fund for U.S. GAAP financial reporting purposes, and the portfolio investments held by the Taxable Subsidiaries are included in MSC Income Fund’s consolidated financial statements as portfolio investments and recorded at fair value. The Taxable Subsidiaries are not consolidated with MSIF for income tax purposes and may generate income tax expense, or benefit, and tax assets and liabilities, as a result of their ownership of certain portfolio investments. The taxable income, or loss, of the Taxable Subsidiaries may differ from their book income, or loss, due to temporary book and tax timing differences and permanent differences. The Taxable Subsidiaries are each taxed at corporate income tax rates based on their taxable income. The income tax expense, or benefit, if any, and the related tax assets and liabilities, of the Taxable Subsidiaries are reflected in MSC Income Fund’s consolidated financial statements.

The Taxable Subsidiaries use the liability method in accounting for income taxes. Deferred tax assets and liabilities are recorded for temporary differences between the tax basis of assets and liabilities and their reported amounts in the consolidated financial statements, using statutory tax rates in effect for the year in which the temporary differences are expected to reverse. A valuation allowance is provided, if necessary, against deferred tax assets when it is more likely than not that some portion or all of the deferred tax asset will not be realized. MSC Income Fund’s net assets as included on the

Consolidated Balance Sheets and Consolidated Statements of Changes in Net Assets include an adjustment to classification as a result of permanent book-to-tax differences, which include differences in the book and tax treatment of income and expenses.

Taxable income generally differs from net income for financial reporting purposes due to temporary and permanent differences in the recognition of income and expenses. Taxable income generally excludes net unrealized appreciation or depreciation, as investment gains or losses are not included in taxable income until they are realized.

8. Net Realized Gains or Losses and Net Unrealized Appreciation or Depreciation

Realized gains or losses are measured by the difference between the net proceeds from the sale or redemption of an investment or a financial instrument and the cost basis of the investment or financial instrument, without regard to unrealized appreciation or depreciation previously recognized, and includes investments written-off during the period net of recoveries and realized gains or losses from in-kind redemptions. Net unrealized appreciation or depreciation reflects the net change in the fair value of the Investment Portfolio and financial instruments and the reclassification of any prior period unrealized appreciation or depreciation on exited investments and financial instruments to realized gains or losses.

9. Fair Value of Financial Instruments

Fair value estimates are made at discrete points in time based on relevant information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. MSC Income Fund believes that the carrying amounts of its financial instruments, consisting of cash and cash equivalents, receivables, payables and other liabilities approximate the fair values of such items due to the short-term nature of these instruments.

To estimate the fair value of MSC Income Fund’s Series A Notes as disclosed in Note E — Debt, MSC Income Fund uses the Yield-to-Maturity valuation method based on projections of the discounted future free cash flows that the debt security will likely generate, including both the discounted cash flows of the associated interest and principal amounts for the debt security. The inputs used to value MSC Income Fund’s debt instrument are considered to be Level 2 according to the ASC 820 fair value hierarchy.

10. Earnings per Share

Net increase in net assets resulting from operations per share and net investment income per share are computed utilizing the weighted-average number of shares of common stock outstanding for the period.

11. Recently Issued or Adopted Accounting Standards

In March 2020, the FASB issued ASU 2020-04, Reference rate reform (Topic 848) — Facilitation of the effects of reference rate reform on financial reporting. The amendments in this update provide optional expedients and exceptions for applying U.S. GAAP to certain contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform and became effective upon issuance for all entities. The Company has agreements that have LIBOR as a reference rate with certain portfolio companies and also with certain lenders. Many of these agreements include language for choosing an alternative successor rate if LIBOR reference is no longer considered to be appropriate. Contract modifications are required to be evaluated in determining whether the modifications result in the establishment of new contracts or the continuation of existing contracts. The Company adopted this amendment in March 2020 and plans to apply the amendments in this update to account for contract modifications due to changes in reference rates when LIBOR reference is no longer used.

In November 2022, the FASB issued ASU 2022-06, Reference rate reform (Topic 848) — Deferral of the Sunset Date of Topic 848, which deferred the sunset date of Topic 848 from December 31, 2022 to December 31, 2024 after which entities will no longer be permitted to apply the relief in Topic 848. The Company utilized the optional expedients and exceptions provided by ASU 2020-04 and extended by ASU 2022-06 during the years ended December 31, 2023 and 2022, the effect of which was not material to the consolidated financial statements and the notes thereto. The Company will continue to utilize the optional expedients provided by ASU 2020-04 and extended by ASU 2022-06 through December 31,

2024. The Company does not expect ASU 2022-06 to have a material impact to the consolidated financial statements and the notes thereto.

In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. The amendments in this update provide that a contractual restriction on the sale of an equity security is not considered part of the unit of account of the equity security and, therefore, is not considered in measuring fair value. The amendments in this update also require additional disclosures for equity securities subject to contractual sales restrictions. ASU 2022-03 is effective for years beginning after December 15, 2023, though early adoption is permitted. The Company elected to early adopt ASU 2022-03 as of December 31, 2022 and it did not have a material impact on the consolidated financial statements and the notes thereto.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. The amendments in this update require more disaggregated information on income taxes paid. ASU 2023-09 is effective for years beginning after December 15, 2024. Early adoption is permitted; however, the Company has not elected to adopt this provision as of the date of the financial statements contained in this report. The Company is still assessing the impact of the new guidance. However, it does not expect ASU 2023-09 to have a material impact on the consolidated financial statements and the notes thereto.

From time to time, new accounting pronouncements are issued by the FASB or other standards-setting bodies that are adopted by the Company as of the specified effective date. The Company believes that the impact of recently issued standards and any that are not yet effective will not have a material impact on its consolidated financial statements upon adoption.

NOTE C —FAIR VALUE HIERARCHY FOR INVESTMENTS—PORTFOLIO COMPOSITION

ASC 820 defines fair value, establishes a framework for measuring fair value, establishes a fair value hierarchy based on the quality of inputs used to measure fair value, and enhances disclosure requirements for fair value measurements. MSC Income Fund accounts for its investments at fair value.

Fair Value Hierarchy

In accordance with ASC 820, MSC Income Fund has categorized its investments based on the priority of the inputs to the valuation technique into a three-level fair value hierarchy. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical investments (Level 1) and the lowest priority to unobservable inputs (Level 3).

Investments recorded on MSC Income Fund’s Consolidated Balance Sheets are categorized based on the inputs to the valuation techniques as follows:

Level 1 — Investments whose values are based on unadjusted quoted prices for identical assets in an active market that MSC Income Fund has the ability to access (examples include investments in active exchange-traded equity securities and investments in most U.S. government and agency securities).

Level 2 — Investments whose values are based on quoted prices in markets that are not active or model inputs that are observable either directly or indirectly for substantially the full term of the investment. Level 2 inputs include the following:

•Quoted prices for similar assets in active markets (for example, investments in restricted stock);

•Quoted prices for identical or similar assets in non-active markets (for example, investments in thinly traded public companies);

•Pricing models whose inputs are observable for substantially the full term of the investment (for example, market interest rate indices); and

•Pricing models whose inputs are derived principally from, or corroborated by, observable market data through correlation or other means for substantially the full term of the investment.

Level 3 — Investments whose values are based on prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement (for example, investments in illiquid securities issued by privately held companies). These inputs reflect management’s own assumptions about the assumptions a market participant would use in pricing the investment.

As required by ASC 820, when the inputs used to measure fair value fall within different levels of the hierarchy, the level within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement in its entirety. For example, a Level 3 fair value measurement may include inputs that are observable (Levels 1 and 2) and unobservable (Level 3). Therefore, unrealized appreciation and depreciation related to such investments categorized within the Level 3 tables below may include changes in fair value that are attributable to both observable inputs (Levels 1 and 2) and unobservable inputs (Level 3).

As of December 31, 2023 and 2022, MSC Income Fund’s Private Loan portfolio investments primarily consisted of investments in secured debt investments. The fair value determination for these investments consisted of a combination of observable inputs in non-active markets for which sufficient observable inputs were not available to determine the fair value of these investments and unobservable inputs. As a result, all of MSC Income Fund’s Private Loan portfolio investments were categorized as Level 3 as of December 31, 2023 and 2022.

As of December 31, 2023 and 2022, all of MSC Income Fund’s LMM portfolio investments consisted of illiquid securities issued by privately held companies and the fair value determination for these investments primarily consisted of unobservable inputs. As a result, all of MSC Income Fund’s LMM portfolio investments were categorized as Level 3 as of December 31, 2023 and 2022.

As of December 31, 2023 and 2022, MSC Income Fund’s Middle Market portfolio investments consisted primarily of investments in secured and unsecured debt investments and independently rated debt investments. The fair value determination for these investments consisted of a combination of observable inputs in non-active markets for which sufficient observable inputs were not available to determine the fair value of these investments and unobservable inputs. As a result, all of MSC Income Fund’s Middle Market portfolio investments were categorized as Level 3 as of December 31, 2023 and 2022.

As of December 31, 2023 and 2022, MSC Income Fund’s Other Portfolio investments consisted of illiquid securities issued by privately held entities and the fair value determination for these investments primarily consisted of unobservable inputs. As a result, all of MSC Income Fund’s Other Portfolio investments were categorized as Level 3 as of December 31, 2023 and 2022.

As of December 31, 2023, all money market funds included in cash and cash equivalents were valued using Level 1 inputs.

The fair value determination of each portfolio investment categorized as Level 3 required one or more of the following unobservable inputs:

•Financial information obtained from each portfolio company, including unaudited statements of operations and balance sheets for the most recent period available as compared to budgeted numbers;

•Current and projected financial condition of the portfolio company;

•Current and projected ability of the portfolio company to service its debt obligations;

•Type and amount of collateral, if any, underlying the investment;

•Current financial ratios (e.g., fixed charge coverage ratio, interest coverage ratio and net debt/ EBITDA ratio) applicable to the investment;

•Current liquidity of the investment and related financial ratios (e.g., current ratio and quick ratio);

•Pending debt or capital restructuring of the portfolio company;

•Projected operating results of the portfolio company;

•Current information regarding any offers to purchase the investment;

•Current ability of the portfolio company to raise any additional financing as needed;

•Changes in the economic environment which may have a material impact on the operating results of the portfolio company;

•Internal occurrences that may have an impact (both positive and negative) on the operating performance of the portfolio company;

•Qualitative assessment of key management;

•Contractual rights, obligations or restrictions associated with the investment; and

•Other factors deemed relevant.

The use of significant unobservable inputs creates uncertainty in the measurement of fair value as of the reporting date. The significant unobservable inputs used in the fair value measurement of MSC Income Fund’s LMM equity securities, which are generally valued through an average of the discounted cash flow technique and the market comparable/enterprise value technique (unless one of these approaches is determined to not be appropriate), are (i) EBITDA multiples and (ii) the weighted-average cost of capital (“WACC”). Significant increases (decreases) in EBITDA multiple inputs in isolation would result in a significantly higher (lower) fair value measurement. On the contrary, significant increases (decreases) in WACC inputs in isolation would result in a significantly lower (higher) fair value measurement. The significant unobservable inputs used in the fair value measurement of MSC Income Fund’s Private Loan, LMM and Middle Market securities are (i) risk adjusted discount rates used in the Yield-to-Maturity valuation technique (see Note B.1. — Summary of Significant Accounting Policies — Valuation of the Investment Portfolio) and (ii) the percentage of expected principal recovery. Significant increases (decreases) in any of these discount rates in isolation would result in a significantly lower (higher) fair value measurement. Significant increases (decreases) in any of these expected principal recovery percentages in isolation would result in a significantly higher (lower) fair value measurement. However, due to the nature of certain investments, fair value measurements may be based on other criteria, such as third-party appraisals of collateral and fair values as determined by independent third parties, which are not presented in the tables below.

The following tables provide a summary of the significant unobservable inputs used to fair value MSC Income Fund’s Level 3 portfolio investments as of December 31, 2023 and 2022:

(1)EBITDA may include proforma adjustments and/or other addbacks based on specific circumstances related to each investment.

(2)Range excludes outliers that are greater than one standard deviation from the mean. Including these outliers, the range for EBITDA multiple is 2.0 x -15.7 x and the range for risk adjusted discount factor is 8.0% -27.3%.

(3)Does not include investments for which the valuation technique does not include the use of the applicable fair value input.

(4)Discount rate includes the effect of the standard SOFR base rate, as applicable.

(1)EBITDA may include proforma adjustments and/or other addbacks based on specific circumstances related to each investment.

(2)Range excludes outliers that are greater than one standard deviation from the mean. Including these outliers, the range for EBITDA multiple is 2.0 x -15.7 x and the range for risk adjusted discount factor is 6.5% -43.3%.

(3)Does not include investments for which the valuation technique does not include the use of the applicable fair value input.

(4)Discount rate includes the effect of the standard LIBOR and SOFR base rate, as applicable.

The following tables provide a summary of changes in fair value of MSC Income Fund’s Level 3 portfolio investments for the years ended December 31, 2023 and 2022 (amounts in thousands):

(1)Includes the impact of non-cash conversions. These transactions represent non-cash investing activities. See additional cash flow information in the Consolidated Statements of Cash Flows.

(1)Includes the impact of non-cash conversions. These transactions represent non-cash investing activities. See additional cash flow information in the Consolidated Statements of Cash Flows.

At December 31, 2023 and 2022, MSC Income Fund’s investments at fair value were categorized as follows in the fair value hierarchy for ASC 820 purposes:

Investment Portfolio Composition

MSC Income Fund’s principal investment objective is to maximize its portfolio’s total return by generating current income from its debt investments and current income and capital appreciation from its equity and equity-related investments, including warrants, convertible securities and other rights to acquire equity securities in a portfolio company. MSC Income Fund seeks to achieve its investment objective through its Private Loan, LMM and Middle Market investment strategies.

MSC Income Fund’s private loan (“Private Loan”) investment strategy is focused on investments in privately held companies that are generally consistent with the size of its LMM portfolio companies or Middle Market portfolio companies, and its Private Loan investments generally range in size from $1 million to $20 million. MSC Income Fund’s Private Loan investments primarily consist of debt securities that have primarily been originated directly by the Adviser or, to a lesser extent, through the Adviser’s strategic relationships with other investment funds on a collaborative basis through investments that are often referred to in the debt markets as “club deals” because of the small lender group size. In both cases, our Private Loan investments are typically made to support a company owned by or in the process of being acquired by a private equity sponsor. MSC Income Fund’s Private Loan portfolio debt investments are generally secured by a first priority lien on the assets of the portfolio company and typically have a term of between three andseven years from the original investment date. MSC Income Fund may have the option to co-invest with Main Street and the private equity sponsor in the equity securities of its Private Loan portfolio companies.

MSC Income Fund’s LMM investment strategy is focused on investments in secured debt, equity warrants and direct equity investments in privately held, LMM companies based in the United States. MSC Income Fund’s LMM portfolio companies generally have annual revenues between $10 million and $150 million, and its LMM investments generally range in size from $1 million to $20 million. The LMM debt investments are typically secured by a first priority lien on the assets of the portfolio company, can include either fixed or floating rate terms and generally have a term of between five andseven years from the original investment date. In most LMM portfolio investments, MSC Income Fund receives nominally priced equity warrants and/or makes direct equity investments in connection with a debt investment.

MSC Income Fund’s Middle Market investment strategy is focused on investments in syndicated loans to or debt securities in Middle Market companies, which MSC Income Fund defines as companies with annual revenues between $150 million and $1.5 billion, and its Middle Market investments generally range in size from $1 million to $20 million. MSC Income Fund’s Middle Market portfolio debt investments are generally secured by a first priority lien on the assets of the portfolio company and typically have an expected duration of between three andseven years from the original investment date.

MSC Income Fund’s other portfolio (“Other Portfolio”) investments primarily consist of investments that are not consistent with the typical profiles for its Private Loan, LMM or Middle Market portfolio investments, including investments which may be managed by third parties. In the Other Portfolio, MSC Income Fund may incur indirect fees and expenses in connection with investments managed by third parties, such as investments in other investment companies or private funds. For Other Portfolio investments, MSC Income Fund generally receives distributions related to the assets held by the portfolio company. Those assets are typically expected to be liquidated over afive toten-year period.

Investment income, consisting of interest, dividends and fees, can fluctuate dramatically due to various factors, including the level of new investment activity, repayments of debt investments or sales of equity interests. Investment income in any given year could also be highly concentrated among several portfolio companies. For the years ended December 31, 2023, 2022 and 2021, MSC Income Fund did not record investment income from any single portfolio company in excess of 10% of total investment income.

The following tables provide a summary of MSC Income Fund’s investments in the Private Loan, LMM and Middle Market portfolios as of December 31, 2023 and 2022 (this information excludes Other Portfolio investments, which are discussed further below):

(a)At December 31, 2023, MSC Income Fund had equity ownership in all of its LMM portfolio companies, and the average fully diluted equity ownership in those portfolio companies was 9%.

(b)The weighted-average annual effective yields were computed using the effective interest rates for all debt investments at cost as of December 31, 2023, including amortization of deferred debt origination fees and accretion of original issue discount but excluding fees payable upon repayment of the debt instruments and any debt investments on non-accrual status. The weighted-average annual effective yield on MSC Income Fund’s debt portfolio as of December 31, 2023 including debt investments on non-accrual status was 12.6% for its Private Loan portfolio,13.0% for its LMM portfolio and 9.9% for its Middle Market portfolio. The weighted-average annual effective yield is not reflective of what an investor in shares of MSC Income Fund’s common stock will realize on its investment because it does not reflect MSC Income Fund’s utilization of debt capital in its capital structure, MSC Income Fund’s expenses or any sales load paid by an investor.

(c)The average EBITDA is calculated using a weighted-average for the Private Loan and Middle Market portfolios and a simple average for the LMM portfolio. These calculations excludeone Private Loan portfolio company, as EBITDA is not a meaningful valuation metric for MSC Income Fund’s investment in this portfolio company and those portfolio companies whose primary purpose is to own real estate.

(a)At December 31, 2022, MSC Income Fund had equity ownership in all of its LMM portfolio companies, and the average fully diluted equity ownership in those portfolio companies was 9%.

(b)The weighted-average annual effective yields were computed using the effective interest rates for all debt investments at cost as of December 31, 2022, including amortization of deferred debt origination fees and accretion of original issue discount but excluding fees payable upon repayment of the debt instruments and any debt investments on non-accrual status. The weighted-average annual effective yield on MSC Income Fund’s debt portfolio as of December 31, 2022 including debt investments on non-accrual status was 11.4% for its Private Loan portfolio,11.7% for its LMM portfolio and 9.7% for its Middle Market portfolio. The weighted-average annual effective yield is not reflective of what an investor in shares of MSC Income Fund’s common stock will realize on its investment because it does not reflect MSC Income Fund’s utilization of debt capital in its capital structure, MSC Income Fund’s expenses or any sales load paid by an investor.

(c)The average EBITDA is calculated using a weighted-average for the Private Loan and Middle Market portfolios and a simple average for the LMM portfolio. These calculations exclude certain portfolio companies, includingone Private Loan portfolio company, as EBITDA is not a meaningful valuation metric for MSC Income Fund’s investment in this portfolio company, and those portfolio companies whose primary purpose is to own real estate.

For the years ended December 31, 2023 and 2022, MSC Income Fund achieved a total return on investments of 13.6% and 9.1%, respectively. Total return on investments is calculated using the interest, dividend and fee income, as well as the realized and unrealized change in fair value of the Investment Portfolio for the specified period. MSC Income Fund’s total return on investments is not reflective of what an investor in shares of MSC Income Fund’s common stock will realize on its investment because it does not reflect MSC Income Fund’s utilization of debt capital in its capital structure, MSC Income Fund’s expenses or any sales load paid by an investor.

As of December 31, 2023, MSC Income Fund had Other Portfolio investments infour entities, collectively totaling $24.6 million in fair value and $21.5 million in cost basis and which comprised 2.3% and 2.1% of MSC Income Fund’s Investment Portfolio at fair value and cost, respectively. As of December 31, 2022, MSC Income Fund had Other Portfolio investments infour entities, collectively totaling $29.0 million in fair value and $24.7 million in cost basis and which comprised 2.7% and 2.3% of MSC Income Fund’s Investment Portfolio at fair value and cost, respectively.

The following tables summarize the composition of MSC Income Fund’s total combined Private Loan, LMM and Middle Market portfolio investments at cost and fair value by type of investment as a percentage of the total combined

Private Loan, LMM and Middle Market portfolio investments, as of December 31, 2023 and 2022 (this information excludes Other Portfolio investments).

The following tables summarize the composition of MSC Income Fund’s total combined Private Loan, LMM and Middle Market portfolio investments by geographic region of the United States and other countries at cost and fair value as a percentage of the total combined Private Loan, LMM and Middle Market portfolio investments, as of December 31, 2023 and 2022 (this information excludes Other Portfolio investments). The geographic composition is determined by the location of the corporate headquarters of the portfolio company.

MSC Income Fund’s Private Loan, LMM and Middle Market portfolio investments are in companies conducting business in a variety of industries. The following tables summarize the composition of MSC Income Fund’s total combined Private Loan, LMM and Middle Market portfolio investments by industry at cost and fair value as of December 31, 2023 and 2022 (this information excludes Other Portfolio investments).

(1)Includes various industries with each industry individually less than 1.0% of the total combined Private Loan, LMM and Middle Market portfolio investments at each date.

(1)Includes various industries with each industry individually less than 1.0% of the total combined Private Loan, LMM and Middle Market portfolio investments at each date.

At December 31, 2023 and 2022, MSC Income Fund had no portfolio investment that was greater than 10% of the Investment Portfolio at fair value.

Unconsolidated Significant Subsidiaries

In accordance with Rules 3-09 and 4-08(g) of Regulation S-X, MSC Income Fund must determine which of its unconsolidated controlled portfolio companies, if any, are considered “significant subsidiaries.” In evaluating its unconsolidated controlled portfolio companies in accordance with Regulation S-X, there are two tests that MSC Income Fund must utilize to determine if any of MSC Income Fund’s Control Investments (as defined in Note A — Organization and Basis of Presentation, including those unconsolidated portfolio companies defined as Control Investments in which MSC Income Fund does not own greater than 50% of the voting securities nor have rights to maintain greater than 50% of the board representation) are considered significant subsidiaries: the investment test and the income test. The investment test is generally measured by dividing MSC Income Fund’s investment in the Control Investment by the value of MSC Income Fund’s total investments. The income test is generally measured by dividing the absolute value of the combined sum of total investment income, net realized gain (loss) and net unrealized appreciation (depreciation) from the relevant Control Investment for the period being tested by the absolute value of MSC Income Fund’s change in net assets resulting from operations for the same period. Rules 3-09 and 4-08(g) of Regulation S-X require MSC Income Fund to include (1) separate audited financial statements of an unconsolidated majority-owned subsidiary (Control Investments in which MSC Income Fund owns greater than 50% of the voting securities) in an annual report and (2) summarized financial information of a Control Investment in a quarterly report, respectively, if certain thresholds of the investment or income tests are exceeded and the unconsolidated portfolio company qualifies as a significant subsidiary.

As of December 31, 2023, 2022 and 2021, MSC Income Fund had no single investment that qualified as a significant subsidiary under either the investment or income tests.

NOTE D —INVESTMENT IN SIGNAL PEAK CLO 7, LTD.

On December 16, 2021, MSC Income Fund sold its entire position in the Signal Peak CLO 7, Ltd., a limited liability company which invested primarily in broadly-syndicated loans, for $17.4 million, resulting in a realized loss of $3.7 million. For the year December 31, 2021, MSC Income Fund recognized $2.2 million of interest income in respect of its investment in Signal Peak CLO.

NOTE E —DEBT

Summary of MSC Income Fund’s debt as of December 31, 2023 is as follows:

(1)The unamortized debt issuance costs for the Credit Facilities are reflected as Deferred financing costs on the Consolidated Balance Sheets, while the deferred debt issuance costs related to the Series A Notes are reflected as a contra-liability to the Series A Notes on the Consolidated Balance Sheets.

(2)Estimated fair value for outstanding debt if MSC Income Fund had adopted the fair value option under ASC 825. See discussion of the methods used to estimate the fair value of MSC Income Fund’s debt in Note B.9. — Summary of Significant Accounting Policies — Fair Value of Financial Instruments.

Summary of MSC Income Fund’s debt as of December 31, 2022 is as follows:

(1)The unamortized debt issuance costs for the Credit Facilities are reflected as Deferred financing costs on the Consolidated Balance Sheets, while the deferred debt issuance costs related to the Series A Notes are reflected as a contra-liability to the Series A Notes on the Consolidated Balance Sheets.

(2)Estimated fair value for outstanding debt if MSC Income Fund had adopted the fair value option under ASC 825. See discussion of the methods used to estimate the fair value of MSC Income Fund’s debt in Note B.9. — Summary of Significant Accounting Policies — Fair Value of Financial Instruments.

Summarized interest expense for the years ended December 31, 2023, 2022 and 2021 is as follows:

(1)Deutsche Bank Credit Facility was fully repaid and extinguished on February 3, 2021.

(2)Main Street Term Loan was fully repaid and extinguished on October 22, 2021.

Corporate Facility

MSC Income Fund is a party to a senior secured revolving credit agreement dated March 6, 2017 (as amended, the “Corporate Facility”) with EverBank (formerly known as TIAA Bank), as administrative agent, and with EverBank and other financial institutions as lenders. As of December 31, 2023, the Corporate Facility included (i) total commitments of $165.0 million, (ii) an accordion feature with the right to request an increase in commitments under the facility from new and existing lenders on the same terms and conditions as the existing commitments up to $200.0 million of total commitments and (iii) a revolving period and maturity date to September 1, 2025 and March 1, 2026, respectively, withtwo, one-year extension options subject to lender approval.

Borrowings under the Corporate Facility bear interest, subject to MSC Income Fund’s election, on a per annum basis at a rate equal to (i) SOFR plus 2.50% or (ii) the base rate plus 1.40%. The base rate is defined as the higher of (a) the Prime rate, (b) the Federal Funds Rate (as defined in the credit agreement) plus 0.5% or (c) SOFR plus 1.1%. Additionally, MSC Income Fund pays an annual unused commitment fee of 0.30% per annum on the unused lender commitments if more than 50% or more of the lender commitments are being used and an annual unused commitment fee of 0.625% per annum on the unused lender commitments if less than 50% of the lender commitments are being used. Borrowings under the Corporate Facility are secured by a first lien on all of the assets of MSIF and its subsidiaries, excluding the assets of

Structured Subsidiaries or immaterial subsidiaries, as well as all of the assets, and a pledge of equity ownership interests, of any future subsidiaries of MSIF (other than Structured Subsidiaries or immaterial subsidiaries). In connection with the Corporate Facility, MSIF has made customary representations and warranties and is required to comply with various covenants, reporting requirements and other customary requirements for similar credit facilities. Effective April 27, 2023, the reference rate under the Corporate Facility was amended from LIBOR to SOFR plus an applicable credit spread adjustment of 0.10%.

As of December 31, 2023, the interest rate on the Corporate Facility was 7.84%. The average interest rate for borrowings under the Corporate Facility was 7.54% and 4.11% for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, MSC Income Fund was in compliance with all financial covenants of the Corporate Facility.

SPV Facility

MSIF Funding LLC (“MSIF Funding”), a wholly-owned Structured Subsidiary that primarily holds originated loan investments, is party to a senior secured revolving credit facility dated February 3, 2021 (as amended, the “SPV Facility” and, together with the Corporate Facility, the “Credit Facilities”) with JPMorgan Chase Bank, National Association (“JPM”), as administrative agent, and U.S. Bank, N.A., as collateral agent and collateral administrator, JPM and other financial institutions as lenders and MSIF as portfolio manager. In August 2023, the SPV facility was amended to extend the revolving period expiration date from February 3, 2024 to February 3, 2027 and the maturity date from February 3, 2025 to February 3, 2028. Additionally, total commitments were reduced from $325.0 million to $300.0 million. Advances under the SPV Facility bear interest at a per annum rate equal to the three month SOFR in effect, plus the applicable margin of 3.00%. MSIF Funding also pays a commitment fee of 0.75% per annum on the average daily unused amount of the financing commitments until February 2, 2027. As of December 31, 2023, the SPV Facility included total commitments of $300.0 million and an accordion feature, with the right to request an increase of total commitments and borrowing availability up to $450.0 million. The SPV Facility is secured by a collateral loan on the assets of MSIF Funding. In connection with the SPV Facility, MSIF Funding has made customary representations and warranties and is required to comply with various covenants, reporting requirements and other customary requirements for similar credit facilities.

As of December 31, 2023, the interest rate on the SPV Facility was 8.39%. The average interest rate for borrowings under the SPV Facility was 8.09% and 4.71% for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, MSIF Funding was in compliance with all financial covenants of the SPV Facility.

Series A Notes

Pursuant to a Master Note Purchase Agreement dated October 21, 2021 (the “Note Purchase Agreement”), MSC Income Fund issued $77.5 million of 4.04% Series A Senior Notes due 2026 (the “Series A Notes”) upon entering into the Note Purchase Agreement and an additional $72.5 million on January 21, 2022. The Series A Notes bear a fixed interest rate of 4.04% per year and will mature on October 30, 2026, unless redeemed, purchased or prepaid prior to such date by the Company in accordance with their terms.

Interest on the Series A Notes is due semiannually on April 30 and October 30 each year, beginning on April 30, 2022. The Series A Notes may be redeemed in whole or in part at any time or from time to time at MSC Income Fund’s option at par plus accrued interest to the prepayment date and, if applicable, a make-whole premium. In addition, MSC Income Fund is obligated to offer to prepay the Series A Notes at par plus accrued and unpaid interest up to, but excluding, the date of prepayment, if certain change in control events occur. In the event that a Below Investment Grade Event (as defined in the Note Purchase Agreement) occurs, the Series A Notes will bear interest at a fixed rate of 5.04% per year from the date of the occurrence of the Below Investment Grade Event to and until the date on which the Below Investment Grade Event ends. The Series A Notes are general unsecured obligations of MSIF that rank pari passu with all outstanding and future unsecured unsubordinated indebtedness issued by MSIF.

The Note Purchase Agreement also contains customary events of default with customary cure and notice periods, including, without limitation, nonpayment, incorrect representation in any material respect, breach of covenant, cross-default under other indebtedness of MSIF or subsidiary guarantors subject to a cure pass-through, certain judgments and orders and certain events of bankruptcy. As of December 31, 2023, MSC Income Fund was in compliance with all financial covenants of the Note Purchase Agreement.

Main Street Term Loan

On January 27, 2021, the Company entered into a term loan agreement (the “Main Street Term Loan”) with Main Street, which initially provided up to an aggregate principal amount of $40.0 million in borrowings. The Company paid a 1.0% upfront fee to Main Street on the closing date. On July 27, 2021, the Company entered into an amendment to the Main Street Term Loan that allowed the Company to draw an additional $20.0 million, with another $15.0 million available to be drawn in two separate $7.5 million tranches (each a “Delayed Draw Term Loan”) at a later date.

Borrowings under the Main Street Term Loan were expressly subordinated and junior in right of payment to all secured indebtedness of the Company. On October 22, 2021, in connection with the issuance of the Series A Notes (discussed above), the Company fully repaid all borrowings outstanding under the Main Street Term Loan, and the Main Street Term Loan was extinguished. As a result, the Company recorded a loss on the extinguishment of debt in the amount of $0.3 million, which represented the write-off of the unamortized deferred financing fees related to the Main Street Term Loan.

Deutsche Bank Credit Facility

On May 18, 2015, HMS Funding I LLC (“HMS Funding”), a wholly-owned Structured Subsidiary, entered into an amended and restated credit agreement (as amended, the “Deutsche Bank Credit Facility”) among HMS Funding, as borrower, MSC Income Fund, as equity holder and as servicer, Deutsche Bank AG, New York Branch (“Deutsche Bank”), as administrative agent, the financial institutions party thereto as lenders (together with Deutsche Bank, the “HMS Funding Lenders”), and U.S. Bank National Association, as collateral agent and collateral custodian. On February 3, 2021, the total amount outstanding on the facility under the Deutsche Bank Credit Facility was fully repaid. As a result, MSC Income Fund recorded a loss on the extinguishment of debt in the amount of $2.1 million, which represented the write-off of the unamortized deferred financing fees related to the Deutsche Bank Credit Facility.

For the year ended December 31, 2021, the average interest rate for borrowings under the Deutsche Bank Credit Facility, excluding amortization of deferred financing costs was 2.93% per annum.

A summary of the Company’s contractual payment obligations for the repayment of outstanding indebtedness at December 31, 2023 is as follows:

(1)At December 31, 2023, MSIF Funding had $96.3 million of undrawn lender commitments under the SPV Facility; however, MSIF Funding’s borrowing ability is limited by leverage and borrowing base restrictions imposed by the SPV Facility and the 1940 Act, as discussed above.

(2)MSC Income Fund issued $77.5 million of Series A Notes upon entering into the Note Purchase Agreement on October 22, 2021 and an additional $72.5 million on January 21, 2022.

(3)At December 31, 2023, MSC Income Fund had $33.0 million of undrawn lender commitments under the Corporate Facility; however, MSC Income Fund’s borrowing ability is limited by leverage and borrowing base restrictions imposed by the Corporate Facility and the 1940 Act, as discussed above.

NOTE F —FINANCIAL HIGHLIGHTS

The following is a schedule of financial highlights of MSC Income Fund for the years ended December 31, 2023, 2022, 2021, 2020 and 2019:

(1)Based on weighted-average number of common shares outstanding for the period.

(2)Net realized gains or losses, net unrealized appreciation or depreciation and income tax provision or benefit can fluctuate significantly from period to period.

(3)Represents stockholder dividends paid or accrued for the period.

(4)Shares repurchased in connection with the modified Dutch auction tender offers. See Note H — Share Repurchases for additional information.

(5)Includes the impact of the different share amounts as a result of calculating certain per share data based on the weighted-average basic shares outstanding during the period and certain per share data based on the shares outstanding as of a period end or transaction date.

(6)Reclassifications have been made to certain prior year per share data. The 2020 “Other” and 2019 “Net investment income” per share amounts have been adjusted to reflect the income tax provision effect separately rather than as a component of these values.

(1)Total expenses are the sum of operating expenses and net income tax provision or benefit. Net income tax provision or benefit includes the accrual of net deferred tax provision or benefit relating to the net unrealized appreciation or depreciation on portfolio investments held in the Taxable Subsidiaries and due to the change in the loss carryforwards, which are non-cash in nature and may vary significantly from period to period. MSC Income Fund is required to include net deferred tax provision or benefit in calculating its total expenses even though these net deferred taxes are not currently payable or receivable.

(2)Unless otherwise noted, operating expenses include interest, management fees, incentive fees and general and administrative expenses.

(3)Total return is calculated based on the change in NAV per share and stockholder distributions declared per share during the reporting period, divided by the NAV per share at the beginning of the period. The total return does not reflect the sales load from the sale of MSC Income Fund’s common stock.

(4)Net of expense waivers of $8.3 million, $4.5 million, $4.3 million, $3.6 million and $3.1 million in 2023, 2022, 2021, 2020 and 2019, respectively. Excluding these expense waivers, the expense and income ratios are as follows:

See footnotes (1), (2), (3) and (4) immediately prior to this table.

NOTE G —DIVIDENDS, DISTRIBUTIONS AND TAXABLE INCOME

MSC Income Fund currently pays quarterly dividends to its stockholders. Future quarterly dividends, if any, will be determined by its Board of Directors on a quarterly basis. MSC Income Fund paid or accrued dividends to its common stockholders of $56.1 million, or $0.700 per share, during the year ended December 31, 2023, compared to $51.6 million, or $0.645 per share, during the year ended December 31, 2022. For tax purposes, the 2023 dividends, which included the effects of dividends on an accrual basis, totaled $56.1 million, or $0.700 per share, and were comprised of (i) ordinary income totaling $0.596 per share and (ii) qualified dividend income totaling $0.104 per share. As of December 31, 2023, MSC Income Fund estimates that it has generated undistributed taxable income of $14.7 million, or $0.18 per share, that will be carried forward toward distributions to be paid in 2024.

MSIF has elected to be treated for U.S. federal income tax purposes as a RIC. MSIF’s taxable income includes the taxable income generated by MSIF and certain of its subsidiaries, including the Structured Subsidiaries, which are treated as disregarded entities for tax purposes. As a RIC, MSIF generally will not pay corporate-level U.S. federal income taxes on any net ordinary taxable income or capital gains that MSIF distributes to its stockholders. MSIF must generally distribute at least 90% of its “investment company taxable income” (which is generally its net ordinary taxable income and realized net short-term capital gains in excess of realized net long-term capital losses) and 90% of its tax-exempt income to maintain its RIC status (pass-through tax treatment for amounts distributed). As part of maintaining RIC status, undistributed taxable income (subject to a 4% non-deductible U.S. federal excise tax) pertaining to a given fiscal year may be distributed up to twelve months subsequent to the end of that fiscal year, provided such dividends are declared on or prior to the later of (i) filing of the U.S. federal income tax return for the applicable fiscal year or (ii) the fifteenth day of the ninth month following the close of the year in which such taxable income was generated.

The determination of the tax attributes for MSC Income Fund’s distributions is made annually, based upon its taxable income for the full year and distributions paid for the full year. Therefore, a determination made on an interim basis may not be representative of the actual tax attributes of distributions for a full year. Ordinary dividend distributions from a RIC do not qualify for the 20% maximum tax rate (plus a 3.8% Medicare surtax, if applicable) on dividend income from domestic corporations and qualified foreign corporations, except to the extent that the RIC received the income in the form of qualifying dividends from domestic corporations and qualified foreign corporations. The tax attributes for distributions will generally include both ordinary income and qualified dividends, but may also include either one or both of capital gains and return of capital.

The tax character of distributions paid for the years ended December 31, 2023, 2022 and 2021 was as follows:

Listed below is a reconciliation of “Net increase in net assets resulting from operations” to taxable income and to total distributions declared to common stockholders for the years ended December 31, 2023, 2022 and 2021.

(1)MSIF’s taxable income for each period is an estimate and will not be finally determined until MSIF files its tax return for each year. Therefore, the final taxable income, and the taxable income earned in each period and carried forward for distribution in the following period, may be different than this estimate.

The Taxable Subsidiaries primarily hold certain equity investments for MSC Income Fund. The Taxable Subsidiaries permit MSC Income Fund to hold equity investments in portfolio companies which are “pass-through” entities for tax purposes and to continue to comply with the “source-of-income” requirements contained in the RIC tax provisions of the Code. The Taxable Subsidiaries are consolidated with MSIF for U.S. GAAP financial reporting purposes, and the portfolio investments held by the Taxable Subsidiaries are included in MSC Income Fund’s consolidated financial statements as portfolio investments and recorded at fair value. The Taxable Subsidiaries are not consolidated with MSIF for income tax purposes and may generate income tax expense, or benefit, and tax assets and liabilities, as a result of their ownership of certain portfolio investments. The taxable income, or loss, of the Taxable Subsidiaries may differ from their book income, or loss, due to temporary book and tax timing differences and permanent differences. The Taxable Subsidiaries are each taxed at corporate income tax rates based on their taxable income. The income tax expense, or benefit, if any, and the related tax assets and liabilities, of the Taxable Subsidiaries are reflected in MSC Income Fund’s consolidated financial statements.

The income tax provision for MSC Income Fund is generally composed of (i) deferred tax expense (benefit), which is primarily the result of the net activity relating to the portfolio investments held in the Taxable Subsidiaries, including changes in loss carryforwards, changes in net unrealized appreciation or depreciation, changes in valuation allowance and other temporary book tax differences, and (ii) current tax expense, which is primarily the result of current U.S. federal income and state taxes and excise taxes on MSC Income Fund’s estimated undistributed taxable income. The income tax expense, or benefit, and the related tax assets and liabilities generated by the Taxable Subsidiaries, if any, are reflected in MSC Income Fund’s Consolidated Statements of Operations. MSC Income Fund’s provision for income taxes was comprised of the following for the years ended December 31, 2023, 2022 and 2021:

MSIF operates in a manner to maintain its RIC status and to eliminate corporate-level U.S. federal income tax (other than the 4% excise tax) by distributing sufficient investment company taxable income and long-term capital gains. As a result, MSIF will have an effective tax rate equal to 0% before the excise tax and income taxes incurred by the Taxable Subsidiaries. As such, a reconciliation of the differences between MSC Income Fund’s reported income tax expense and its tax expense at the federal statutory rate of 21% is not meaningful.

As of December 31, 2023, the cost of investments for U.S. federal income tax purposes was $1,035.0 million, with such investments having an estimated net unrealized appreciation of $57.9 million, composed of gross unrealized appreciation of $154.3 million and gross unrealized depreciation of $96.4 million. As of December 31, 2022, the cost basis of investments for tax purposes was $1,059.9 million, with such investments having an estimated net unrealized appreciation of $8.3 million, composed of gross unrealized appreciation of $122.6 million and gross unrealized depreciation of $114.3 million.

The following table sets forth the significant components of net deferred tax assets and liabilities as of December 31, 2023 and 2022:

The net deferred tax liability at December 31, 2023 was $3.3 million. The net deferred tax liability at December 31, 2022 was $0.4 million. Management believes that the realization of the deferred tax assets is more likely than not based on expectations as to future taxable income and scheduled reversals of temporary differences. Accordingly, MSC Income Fund didnot record a valuation allowance related to its deferred tax assets as of December 31, 2023 and 2022.

At December 31, 2023, for U.S. federal income tax purposes, the Taxable Subsidiaries had net operating loss carryforwards from prior years which, if unused, will expire in 2037. Any net operating losses generated in 2018 and future periods are not subject to expiration and will carry forward indefinitely until utilized. The net capital loss carryforwards of the Taxable Subsidiaries will expire in various taxable years 2025 through 2027. Additionally, the Taxable Subsidiaries have interest expense limitation carryforwards, which have an indefinite carryforward period. In addition, as of December 31, 2023, for U.S. federal income tax purposes at the RIC level, MSIF didnot have capital loss carryforwards available to offset future capital gains, to the extent available and permitted by U.S. federal income tax law.

NOTE H —SHARE REPURCHASES

Under the terms of its share repurchase program, MSC Income Fund offers to purchase shares at the NAV per share on the repurchase date. The amount of shares of MSC Income Fund’s common stock to be repurchased during any calendar quarter may be equal to the lesser of (i) the number of shares of common stock MSC Income Fund could repurchase with the proceeds it received from the issuance of common stock under MSC Income Fund’s dividend reinvestment plan or (ii)2.5% of the weighted-average number of shares of common stock outstanding in the prior four calendar quarters. Repurchase offers are currently limited to the number of shares of common stock MSC Income Fund can repurchase with 90% of the cash retained as a result of issuances of common stock under its dividend reinvestment plan.

At the discretion of the Board of Directors, MSC Income Fund may also use cash on hand, cash available from borrowings and cash from the sale of investments as of the end of the applicable period to repurchase shares. MSC Income Fund’s Board of Directors may amend, suspend or terminate the share repurchase program upon 30 days’ notice.

In addition to its share repurchase program, during the fiscal year ended December 31, 2023, MSC Income Fund used proceeds from the sale of their shares during 2023 to complete three modified Dutch auction tender offers, pursuant to which MSC Income Fund offered to purchase up to a specified amount of shares of its common stock at the lowest clearing purchase price elected by participating stockholders within a specified range that allowed MSC Income Fund to purchase the maximum amount offered. All shares purchased in a “Dutch auction” tender offer were purchased at the clearing purchase price. SEC rules permitted MSC Income Fund to increase the number of shares accepted for purchase in any offer by up to 2% of MSC Income Fund’s outstanding shares without amending the offer.

Since inception of its share repurchase program, MSC Income Fund has funded the repurchase of $153.5 million in shares of common stock, including the shares repurchased by MSC Income Fund under the “Dutch auction” tender offers, as of December 31, 2023. For the years ended December 31, 2023, 2022 and 2021, MSC Income Fund funded $24.4 million, $16.0 million and $10.1 million, respectively, for shares of its common stock tendered for repurchase under the plan. For the year ended December 31, 2023, MSC Income Fund purchased 1,267,667 shares of its common stock for $7.8 million through its modified Dutch auction tender offers.

Repurchases of MSC Income Fund’s common stock pursuant to its share repurchase program and modified Dutch auction tender offers for the years ended December 31, 2023, 2022 and 2021 are as follows:

(1) Includes 406,904 shares repurchased under the Dutch auction tender offer pursuant to the to the tender offer statement and Offer to Purchase filed with the SEC on May 15, 2023 at a price of $5.50 per share for an aggregate cost of $2.2 million.

(2) Includes 432,920 shares repurchased under the Dutch auction tender offer pursuant to the to the tender offer statement and Offer to Purchase filed with the SEC on June 14, 2023 at a price of $6.50 per share for an aggregate cost of $2.8 million.

(3) Includes 427,843 shares repurchased under the Dutch auction tender offer pursuant to the to the tender offer statement and Offer to Purchase filed with the SEC on November 15, 2023 at a price of $6.50 per share for an aggregate cost of $2.8 million

NOTE I —DIVIDEND REINVESTMENT PLAN

MSC Income Fund’s dividend reinvestment plan (the “DRIP”) provides for the reinvestment of dividends on behalf of stockholders. As a result, if MSC Income Fund declares a cash dividend, stockholders who have “opted in” to the DRIP will have their cash dividend automatically reinvested into additional shares of MSC Income Fund common stock. The number of shares of common stock to be issued to a stockholder under the DRIP shall be determined by dividing the total dollar amount of the distribution payable to such stockholder by a price per share of common stock determined by MSC Income Fund’s Board of Directors or a committee thereof, in its sole discretion, that is (i) not less than the NAV per share of common stock determined in good faith by the Board of Directors or a committee thereof, in its sole discretion, within 48 hours prior to the payment of the distribution and (ii) not more than 2.5% greater than the NAV per share as of such date.

Summarized DRIP information for the years ended December 31, 2023, 2022 and 2021 is as follows:

NOTE J —COMMITMENTS AND CONTINGENCIES

At December 31, 2023, MSC Income Fund had the following outstanding commitments (in thousands):

MSC Income Fund will fund its unfunded commitments from the same sources it uses to fund its investment commitments that are funded at the time they are made (which are typically through existing cash and cash equivalents and borrowings under the Credit Facilities). MSC Income Fund follows a process to manage its liquidity and ensure that it has available capital to fund its unfunded commitments as necessary. MSC Income Fund had no unrealized appreciation or depreciation on the outstanding unfunded commitments as of December 31, 2023.

MSC Income Fund may, from time to time, be involved in litigation arising out of its operations in the normal course of business or otherwise. Furthermore, third parties may try to impose liability on MSC Income Fund in connection with the activities of its portfolio companies. While the outcome of any current legal proceedings cannot at this time be predicted with certainty, MSC Income Fund does not expect any current matters will materially affect its financial condition or results of operations; however, there can be no assurance whether any pending legal proceedings will have a material adverse effect on MSC Income Fund’s financial condition or results of operations in any future reporting period.

NOTE K —RELATED PARTY TRANSACTIONS

1. Advisory Agreements and Conditional Expense Reimbursement Waivers

On October 30, 2020, MSC Income Fund entered into the Investment Advisory Agreement with the Adviser, which states that the Adviser will oversee the management of MSC Income Fund’s activities and is responsible for making investment decisions with respect to, and providing day‑to‑day management and administration of, MSC Income Fund’s Investment Portfolio. The Investment Advisory Agreement was most recently re-approved by the Board of Directors, including a majority of members who are not “interested” persons (as defined by the 1940 Act) of MSC Income Fund or the Adviser, on August 10, 2023.

Pursuant to the Investment Advisory Agreement, MSC Income Fund pays the Adviser a base management fee and incentive fees as compensation for the services described above. The base management fee is calculated at an annual rate of 1.75% of MSC Income Fund’s average gross assets. The term “gross assets” means total assets of MSC Income Fund as disclosed on MSC Income Fund’s Consolidated Balance Sheets. “Average gross assets” are calculated based on MSC Income Fund’s gross assets at the end of the two most recently completed calendar quarters. The base management fee is payable quarterly in arrears. The base management fee is expensed as incurred.

The incentive fee under the Investment Advisory Agreement consists oftwo parts. The first part, referred to as the subordinated incentive fee on income, is calculated and payable quarterly in arrears based on Pre-Incentive Fee Net Investment Income (as defined below) for the immediately preceding quarter. The subordinated incentive fee on income is equal to 20.0% of MSC Income Fund’s Pre-Incentive Fee Net Investment Income for the immediately preceding quarter, expressed as a quarterly rate of return on adjusted capital at the beginning of the most recently completed calendar quarter, exceeding 1.875% (or 7.5% annualized), subject to a “catch up” feature (as described below).

For this purpose, 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 MSC Income Fund receives from portfolio companies) accrued during the calendar quarter, minus MSC Income Fund’s operating expenses for the quarter (including the management fee, expenses payable under any proposed administration agreement and any interest expense and dividends paid on any issued and outstanding preferred stock, but excluding taxes and the incentive fee). Pre-Incentive Fee Net Investment Income includes, in the case of investments with a deferred interest feature (such as original issue discount debt instruments and PIK interest and zero coupon securities), accrued income that MSC Income Fund has not yet received in cash. Pre-Incentive Fee Net Investment Income does not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation. For purposes of this fee, adjusted capital means cumulative gross proceeds generated from sales of MSC Income Fund’s common stock (including proceeds from MSC Income Fund’s DRIP) reduced for non-liquidating distributions, other than distributions of profits, paid to MSC Income Fund’s stockholders and amounts paid for share repurchases pursuant to MSC Income Fund’s share repurchase program. The subordinated incentive fee on income is expensed in the quarter in which it is incurred.

The calculation of the subordinated incentive fee on income for each quarter is as follows:

•No subordinated incentive fee on income shall be payable to the Adviser in any calendar quarter in which MSC Income Fund’s Pre-Incentive Fee Net Investment Income does not exceed the hurdle rate of 1.875% (or 7.5% annualized) on adjusted capital;

•100% of MSC Income Fund’s Pre-Incentive Fee Net Investment Income, if any, that exceeds the hurdle rate but is less than or equal to 2.34375% in any calendar quarter (9.375% annualized) shall be payable to the Adviser. This portion of the subordinated incentive fee on income is referred to as the “catch up” and is intended to provide the Adviser with an incentive fee of 20.0% on all of MSC Income Fund’s Pre-Incentive Fee Net Investment Income as if the hurdle rate did not apply when the Pre-Incentive Fee Net Investment Income exceeds 2.34375% (9.375% annualized) in any calendar quarter; and

•For any quarter in which MSC Income Fund’s Pre-Incentive Fee Net Investment Income exceeds 2.34375% (9.375% annualized), the subordinated incentive fee on income shall equal 20.0% of the amount of MSC Income Fund’s Pre-Incentive Fee Net Investment Income, as the hurdle rate and catch-up will have been achieved.

The second part of the incentive fee, referred to as the incentive fee on capital gains, is an incentive fee on realized capital gains earned from the portfolio of MSC Income Fund and is determined and payable in arrears as of the end of each calendar year (or upon termination of the Investment Advisory Agreement). This fee equals 20.0% of MSC Income Fund’s incentive fee capital gains, which equals MSC Income Fund’s realized capital gains on a cumulative basis from inception, calculated as of the end of each calendar year, computed net of all realized capital losses and unrealized capital depreciation on a cumulative basis, less the aggregate amount of any previously paid capital gain incentive fees. At the end of each reporting period, MSC Income Fund estimates the incentive fee on capital gains and accrues the fee based on a hypothetical liquidation of its portfolio. Therefore, the accrual includes both net realized gains and net unrealized gains (the net unrealized difference between the fair value and the par value of its portfolio), if any. The incentive fee accrued pertaining to the unrealized gain is neither earned nor payable to the Adviser until such time it is realized.

For the years ended December 31, 2023, 2022 and 2021, MSC Income Fund incurred base management fees of $19.8 million, $19.8 million and $17.3 million, respectively. For the years ended December 31, 2023, 2022 and 2021, MSC Income Fund incurred subordinated incentive fees on income of $12.6 million, $2.1 million and $0.6 million, respectively. For the years ended December 31, 2023, 2022 and 2021, MSC Income Fund didnot incur any capital gains incentive fees.

Pursuant to the Investment Advisory Agreement, MSC Income Fund is required to pay or reimburse the Adviser for administrative services expenses, which include all costs and expenses related to MSC Income Fund’s day-to-day administration and management not related to advisory services, whether such administrative services were performed by a third-party service provider or the Adviser or its affiliates (to the extent performed by the Adviser or its affiliates, the “Internal Administrative Services”). Internal Administrative Services include, but are not limited to, the cost of an Adviser’s personnel performing accounting and compliance functions and other administrative services on behalf of MSC Income Fund.

The Adviser waived reimbursement of all Internal Administrative Services expenses from October 30, 2020 through December 31, 2021. On January 1, 2022, the Adviser assumed responsibility of certain administrative services that were previously provided for MSC Income Fund by a third-party sub-administrator. After December 31, 2021, the Adviser continued to waive reimbursement of all Internal Administrative Services expenses, except for the cost of the services previously provided by the sub-administrator. For the years ended December 31, 2023, 2022 and 2021, MSC Income Fund incurred Internal Administrative Services Expenses of $8.9 million, $5.1 million and $4.3 million, respectively. For the years ended December 31, 2023, 2022 and 2021, the Adviser waived the reimbursements of Internal Administrative Services expenses of $8.3 million, $4.5 million and $4.3 million, respectively. Waived Internal Administrative Services expenses are permanently waived and are not subject to future reimbursement.

2. Offering Costs

In accordance with MSC Income Fund’s previous investment advisory agreement with the previous investment adviser (“HMS Adviser”), MSC Income Fund reimbursed HMS Adviser for any offering costs that were paid on MSC Income Fund’s behalf, which consisted of, among other costs, actual legal, accounting, bona fide out-of-pocket itemized and detailed due diligence costs, printing, filing fees, transfer agent costs, postage, escrow fees, advertising and sales literature and other costs incurred in connection with the offering of MSC Income Fund’s common stock, including through MSC Income Fund’s DRIP. HMS Adviser was responsible for the payment of offering costs to the extent they exceeded 1.5% of the aggregate gross stock offering proceeds. Pursuant to the transaction whereby the Adviser became the investment adviser to MSC Income Fund, HMS Adviser agreed to permanently waive reimbursement of organizational and offering expenses except for $0.6 million which remained payable to HMS Adviser and would be reimbursed as part of future issuances of common stock by MSC Income Fund. For the years ended December 31, 2023 and 2022, MSC Income Fund reimbursed HMS Adviser $0.1 million and $0.3 million, respectively, in connection with stock issuances. As of June 30, 2023, MSC Income Fund’s reimbursement obligation to HMS Adviser for organizational and offering expenses was fully repaid.

3. Indemnification

The Investment Advisory Agreement provides that the Adviser and its officers, directors, controlling persons and any other person or entity affiliated with it acting as MSC Income Fund’s agent are entitled to indemnification (including reasonable attorneys’ fees and amounts reasonably paid in settlement) for any liability or loss suffered by such indemnitee, and such indemnitee will be held harmless for any loss or liability suffered by MSC Income Fund, if (i) the indemnitee has determined, in good faith, that the course of conduct which caused the loss or liability was in MSC Income Fund’s best interests, (ii) the indemnitee was acting on behalf of or performing services for MSC Income Fund, (iii) the liability or loss suffered was not the result of negligence, willful malfeasance, bad faith or misconduct by the indemnitee or an affiliate thereof acting as MSC Income Fund’s agent and (iv) the indemnification or agreement to hold the indemnitee harmless is only recoverable out of MSC Income Fund’s net assets and not from MSC Income Fund’s stockholders.

4. Co-Investment

In the ordinary course of business, MSC Income Fund enters into transactions with other parties that may be considered related party transactions. MSC Income Fund has implemented certain policies and procedures, both written and unwritten, to ensure that it does not engage in any prohibited transactions with any persons affiliated with MSC Income Fund. If such affiliations are found to exist, MSC Income Fund seeks the Board of Directors and/or appropriate Board of Directors committee review and approval for such transactions and otherwise comply with, or seek, orders for exemptive relief from the SEC, as appropriate.

MSC Income Fund has received an exemptive order from the SEC permitting co-investments among MSC Income Fund, Main Street and other funds and clients advised by the Adviser in certain negotiated transactions where co-investing would otherwise be prohibited under the 1940 Act. MSC Income Fund has made co-investments, and in the future intends to continue to make co-investments with Main Street and other funds and clients advised by the Adviser, in accordance with the conditions of the order. The order requires, among other things, that the Adviser and Main Street consider whether each such investment opportunity is appropriate for MSC Income Fund, Main Street and the other funds and clients advised by the Adviser, as applicable, and if it is appropriate, to propose an allocation of the investment opportunity between such parties. Because the Adviser is wholly-owned by Main Street and is not managing MSC Income Fund’s investment activities as its sole activity, this may provide the Adviser an incentive to allocate opportunities to other participating funds and clients instead of MSC Income Fund. However, the Adviser has policies and procedures in place to manage this conflict, including oversight by the independent members of the Board of Directors. Additional information regarding the operation of the co-investment program is set forth in the order granting exemptive relief, which may be reviewed on the SEC’s website at www.sec.gov. In addition to the co-investment program described above, MSC Income Fund also co-invests in syndicated deals and other transactions where price is the only negotiated point by MSC Income Fund and its affiliates.

5. Other Related Party Transactions

On January 27, 2021, MSC Income Fund entered into the Main Street Term Loan, which initially provided for an aggregate principal amount of $40.0 million in borrowings. MSC Income Fund paid a 1.0% upfront fee to Main Street on the closing date.

On July 27, 2021, MSC Income Fund entered into an amendment to the Main Street Term Loan that allowed MSC Income Fund to initially draw an additional $20.0 million, with another $15.0 million available to be drawn in two separate $7.5 million tranches at a later date. Following the amendment, as of September 30, 2021, the aggregate principal amount outstanding under the Main Street Term Loan was $60.0 million bearing interest at a fixed rate of 5.00% per annum and maturing on January 27, 2026.

Borrowings under the Main Street Term Loan were expressly subordinated and junior in right of payment to all secured indebtedness of MSC Income Fund. The Main Street Term Loan was unanimously approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in Section 2(a)(19) of the 1940 Act, of MSC Income Fund or the Adviser. On October 22, 2021, MSC Income Fund fully repaid all borrowings outstanding under the Main Street Term Loan and the Main Street Term Loan was extinguished.

On May 2, 2022, the Company sold 94,697 shares of its common stock to Main Street at $7.92 per share, the price at which the Company issued new shares in connection with reinvestments of the May 2, 2022 dividend pursuant to the DRIP, for total proceeds to the Company of $750,000. The issuance and sale were made pursuant to the exemption from registration under Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and were unanimously approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in Section 2(a)(19) of the 1940 Act, of the Company or the Adviser.

On May 1, 2023, the Company sold 255,754 shares of its common stock to Main Street at $7.82 per share, the price at which the Company issued new shares in connection with reinvestments of the May 1, 2023 dividend pursuant to the DRIP, for total proceeds to the Company of $2.0 million. The issuance and sale were made pursuant to the exemption from registration under Section 4(a)(2) of the Securities Act and were unanimously approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in Section 2(a)(19) of the 1940 Act, of the Company or the Adviser.

On August 1, 2023, the Company sold 348,542 shares of its common stock to Main Street at $7.89 per share, the price at which the Company issued new shares in connection with reinvestments of the August 1, 2023 dividend pursuant to the DRIP, for total proceeds to the Company of $2.8 million. The issuance and sale were made pursuant to the exemption from registration under Section 4(a)(2) of the Securities Act and were unanimously approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in Section 2(a)(19) of the 1940 Act, of the Company or the Adviser.

On November 1, 2023, the Company sold 475,888 shares of its common stock to Main Street at $7.88 per share, the price at which the Company issued new shares in connection with reinvestments of the November 1, 2023 dividend pursuant to the DRIP, for total proceeds to the Company of $3,750,000. The issuance and sale were made pursuant to the exemption from registration under Section 4(a)(2) of the Securities Act and were unanimously approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in Section 2(a)(19) of the 1940 Act, of the Company or the Adviser.

In September 2023, pursuant to the August Dutch auction tender offer, Main Street purchased 115,385 shares of MSC Income Fund common stock from MSC Income Fund stockholders at the August Clearing Price, or $6.50 per share, for an aggregate cost of $0.8 million. See Note H – Share Repurchases for more information. The August Dutch auction tender offer, including Main Street’s participation, were unanimously approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in Section 2(a)(19) of the 1940 Act, of the Company or the Adviser.

NOTE L —SUBSEQUENT EVENTS

On January 31, 2024, the Company sold 314,070 shares of its common stock to Main Street at $7.96 per share,

the price at which the Company issued new shares in connection with reinvestments of the January 31, 2024 dividend

pursuant to the DRIP, for total proceeds to the Company of $2.5 million. The issuance and sale were made pursuant to the

exemption from registration under Section 4(a)(2) of the Securities Act and were unanimously

approved by the Board of Directors, including each director who is not an “interested person,” as such term is defined in

Section 2(a)(19) of the 1940 Act, of the Company or the Adviser.

On January 31, 2024, MSC Income Fund repurchased 518,173 shares of its common stock validly tendered and not withdrawn on the terms set forth in the tender offer statement on Schedule TO and Offer to Purchase filed with the SEC on December 21, 2023. The shares were repurchased at a price of $7.81 per share, which was MSC Income Fund’s NAV per share as of January 31, 2024, for an aggregate purchase price of $4.0 million (an amount equal to 90% of the proceeds MSC Income Fund received from the issuance of shares under MSC Income Fund’s DRIP from the January 31, 2024 dividend payment).

On February 5, 2024, MSC Income Fund commenced a modified “Dutch Auction” tender offer (the “February Dutch Auction Tender Offer”) pursuant to the Offer to Purchase, dated February 5, 2024, which expired on March 4, 2024. Pursuant to the February Dutch Auction Tender Offer, MSC Income Fund repurchased 357,143 shares on March 8, 2024, at a price of $7.00 per share for an aggregate cost of $2.5 million, excluding fees and expenses related to the February Dutch Auction Tender Offer.

On March 7, 2024, the Board of Directors declared a quarterly cash dividend of $0.185 per share payable May 1, 2024 to stockholders of record as of March 29, 2024. Additionally, the Board of Directors approved a repurchase offer pursuant to the Company’s share repurchase program in an amount equal to 90% of the proceeds resulting from shares issued in lieu of cash distributions from the May 1, 2024 dividend payment.