Main Street Capital CORP

ORGANIZATION

Main Street Capital Corporation (“MSCC” or, together with its consolidated subsidiaries, “Main Street” or the “Company”) is a principal investment firm primarily focused on providing customized long-term debt and equity capital solutions to lower middle market (“LMM”) companies (its “LMM investment strategy”) and debt capital to private (“Private Loan”) companies owned by or in the process of being acquired by a private equity fund (its “Private Loan investment strategy”). Main Street’s portfolio investments are typically made to support management buyouts, recapitalizations, growth financings, refinancings and acquisitions of companies that operate in diverse industry sectors. Main Street seeks to partner with entrepreneurs, business owners and management teams and generally provides “one-stop” debt and equity financing alternatives within its LMM investment strategy. Main Street invests primarily in secured debt investments, equity investments, warrants and other securities of LMM companies typically based in the United States. Main Street also seeks to partner with private equity fund sponsors in its Private Loan investment strategy and primarily invests in secured debt investments of Private Loan companies generally headquartered in the United States.

Main Street also maintains a legacy portfolio of investments in larger middle market (“Middle Market”) companies (its “Middle Market investment portfolio”) and a limited portfolio of other portfolio (“Other Portfolio”) investments. Main Street’s Middle Market investments are generally debt investments in companies owned by a private equity fund that were originally issued through a syndication financing process. Main Street has generally stopped making new Middle Market investments and expects the size of its Middle Market investment portfolio to continue to decline in future periods as its existing Middle Market investments are repaid or sold. Main Street’s Other Portfolio investments primarily consist of investments that are not consistent with the typical profiles for its LMM, Private Loan or Middle Market portfolio investments, including investments in unaffiliated investment companies and private funds managed by third parties. The “Investment Portfolio,” as used herein, refers to all of Main Street’s investments in LMM portfolio companies, investments in Private Loan portfolio companies, investments in Middle Market portfolio companies, Other Portfolio investments, short-term portfolio investments (as discussed in Note C — Fair Value Hierarchy for Investments — Portfolio Composition — Investment Portfolio Composition) and the investment in the External Investment Manager (as defined below).

MSCC was formed in March 2007 to operate as an internally managed business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). Because MSCC is internally managed, all of the executive officers and other employees are employed by MSCC. Therefore, MSCC does not pay any external investment advisory fees, but instead directly incurs the operating costs associated with employing investment and portfolio management professionals.

MSCC wholly owns several investment funds, including Main Street Mezzanine Fund, LP (“MSMF”) and Main Street Capital III, LP (“MSC III” and, together with MSMF, the “Funds”), and each of their general partners. The Funds are each licensed as a Small Business Investment Company (“SBIC”) by the United States Small Business Administration (“SBA”).

MSC Adviser I, LLC (the “External Investment Manager”) was formed in November 2013 as a wholly-owned subsidiary of Main Street to provide investment management and other services to parties other than Main Street (“External Parties”) and receives fee income for such services. MSCC has been granted no-action relief by the Securities and Exchange Commission (“SEC”) to allow the External Investment Manager to register as a registered investment adviser under the Investment Advisers Act of 1940, as amended. Since the External Investment Manager conducts all of its investment management activities for External Parties, it is accounted for as a portfolio investment of Main Street and is not included as a consolidated subsidiary in Main Street’s consolidated financial statements.

MSCC 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, MSCC 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.

MSCC 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 MSCC to hold equity investments in portfolio companies which are “pass-through” entities for tax purposes. MSCC 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 “Main Street” refer to MSCC and its consolidated subsidiaries, which include the Funds, the Taxable Subsidiaries and the Structured Subsidiaries.

The following diagram depicts our organizational structure:

• Other Holding Companies includes the Taxable Subsidiaries, the Structured Subsidiaries and other consolidated entities formed for operational purposes. Each of these companies is directly or indirectly wholly-owned by MSCC.

** The External Investment Manager is accounted for as a portfolio investment at fair value, as opposed to a consolidated subsidiary, and is indirectly wholly-owned by MSCC.

CORPORATE INFORMATION

Our principal executive offices are located at 1300 Post Oak Boulevard, 8 th Floor, Houston, Texas 77056. We maintain a website on the Internet atwww.mainstcapital.com. We make available free of charge on our website our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and all amendments to those reports as soon as reasonably practicable after such material is electronically filed with or furnished to the SEC. Information contained on our website is not incorporated by reference into this Annual Report on Form 10-K, and you should not consider that information to be part of this Annual Report on Form 10-K. Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and all amendments to those reports and other public filings are also available free of charge on the EDGAR Database on the SEC’s website atwww.sec.gov.

OVERVIEW OF OUR BUSINESS

Our principal investment objective is to maximize our investment portfolio’s total return by generating current income from our debt investments and current income and capital appreciation from our equity and equity-related investments, including warrants, convertible securities and other rights to acquire equity securities in a portfolio company. We seek to achieve our investment objective through our LMM and Private Loan investment strategies. Our LMM investment strategy involves investments in companies that generally have annual revenues between $10 million and $150 million and annual earnings before interest, tax, depreciation and amortization expenses (“EBITDA”) between $3 million and $20 million. Our LMM portfolio investments generally range in size from $5 million to $125 million. Our Private Loan investment strategy involves investments in companies that generally have annual revenues between $25 million and $500 million and annual EBITDA between $7.5 million and $50 million. Our Private Loan investments generally range in size from $10 million to $100 million.

We seek to fill the financing gap for LMM businesses, which, historically, have had limited access to financing from commercial banks and other traditional sources. The underserved nature of the LMM creates the opportunity for us to meet the financing needs of LMM companies while also negotiating favorable transaction terms and equity participation. Our ability to invest across a company’s capital structure, from secured loans to equity securities, allows us to offer portfolio companies a comprehensive suite of financing options, or a “one-stop” financing solution. We believe that providing customized, “one-stop” financing solutions is important and valuable to LMM portfolio companies. We generally seek to partner directly with entrepreneurs, management teams and business owners in making our LMM investments. Our LMM portfolio debt investments are generally secured by a first lien on the assets of the portfolio company and typically have a term of between five and seven years from the original investment date.

Private Loan investments primarily consist of debt securities that have primarily been originated directly by us or, to a lesser extent, through our 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. Our Private Loan investments are typically made in a company owned by or in the process of being acquired by a private equity fund. Our 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 and seven years from the original investment date. We may also co-invest with the private equity fund in the equity securities of our Private Loan portfolio companies.

We also maintain a legacy portfolio of investments in larger Middle Market companies. Our Middle Market investments are generally debt investments in companies owned by private equity funds that were originally issued through a syndication financing process. We have generally stopped making new Middle Market investments and expect the size of our Middle Market investment portfolio to continue to decline in future periods as existing Middle Market investments are repaid or sold. Our Middle Market debt investments generally range in size from $3 million to $25 million, are generally secured by a first priority lien on the assets of the portfolio company and typically have an expected duration of between three and seven years from the original investment date.

Our Other Portfolio investments primarily consist of investments that are not consistent with the typical profiles for our LMM, Private Loan or Middle Market portfolio investments, including investments which may be managed by third parties. In our Other Portfolio, we may incur indirect fees and expenses in connection with investments managed by third parties, such as investments in other investment companies or private funds.

Subject to changes in our cash and overall liquidity, our Investment Portfolio (as defined below) may also include short-term portfolio investments that are atypical of our LMM, Private Loan and Middle Market portfolio investments in that they are intended to be a short-term deployment of capital. These assets are typically expected to be realized in one year or less and are not expected to be a significant portion of our overall Investment Portfolio. The Investment Portfolio, as used herein, refers to all of our investments in LMM portfolio companies, investments in Private Loan portfolio companies, investments in Middle Market portfolio companies, Other Portfolio investments, short-term portfolio investments and our investment in the External Investment Manager.

Our external asset management business is conducted through the External Investment Manager. The External Investment Manager earns management fees based on the assets of the funds under management and may earn incentive fees, or a carried interest, based on the performance of the funds managed.

Our portfolio investments are generally made through MSCC, the Taxable Subsidiaries, the Funds and the Structured Subsidiaries. MSCC, the Taxable Subsidiaries, the Funds and the Structured Subsidiaries share the same investment strategies and criteria, although they are subject to different regulatory regimes (see Regulation). An investor’s return in MSCC will depend, in part, on the Taxable Subsidiaries’, the Funds’ and the Structured Subsidiaries’ investment returns as they are wholly-owned subsidiaries of MSCC.

The level of new portfolio investment activity will fluctuate from period to period based upon our view of the current economic fundamentals, our ability to identify new investment opportunities that meet our investment criteria and our ability to consummate the identified opportunities. The level of new investment activity, and associated interest and fee income, will directly impact future investment income. In addition, the level of dividends paid by portfolio companies and the portion of our portfolio debt investments on non-accrual status will directly impact future investment income. While we intend to grow our portfolio and our investment income over the long term, our growth and our operating results may be more limited during depressed economic periods. However, we intend to appropriately manage our cost structure and liquidity position based on applicable economic conditions and our investment outlook. The level of realized gains or losses and unrealized appreciation or depreciation on our investments will also fluctuate depending upon portfolio activity, economic conditions and the performance of our individual portfolio companies. The changes in realized gains and losses and unrealized appreciation or depreciation could have a material impact on our operating results.

Because we are internally managed, we do not pay any external investment advisory fees, but instead directly incur the operating costs associated with employing investment and portfolio management professionals. We believe that our internally managed structure provides us with a better alignment of interests between our management team and our employees and our shareholders and a beneficial operating expense structure when compared to other publicly traded and privately held investment firms which are externally managed, and our internally managed structure allows us the opportunity to leverage our non-interest operating expenses as we grow our Investment Portfolio and our External Investment Manager’s asset management business (as described below). For each of the years ended December 31, 2024 and 2023, the ratio of our total operating expenses, excluding interest expense, as a percentage of our quarterly average total assets was 1.3%. The ratio of our total operating expenses, including interest expense, as a percentage of our quarterly average total assets was 3.8% and 3.7%, respectively, for the years ended December 31, 2024 and 2023. Our ratio of expenses as a percentage of our average net asset value is described in greater detail in Note F — Financial Highlights to the consolidated financial statements included in Item 8. Consolidated Financial Statements and Supplementary Data of this Annual Report on Form 10-K.

The External Investment Manager serves as the investment adviser and administrator to MSC Income Fund, Inc. (“MSC Income”) pursuant to an Investment Advisory and Administrative Services Agreement entered into in October 2020 between the External Investment Manager and MSC Income (as amended and restated on January 29, 2025, the “Advisory Agreement”). Under the Advisory Agreement, prior to January 29, 2025, the External Investment Manager earned a 1.75% annual base management fee on MSC Income’s average total assets, a subordinated incentive fee on income equal to 20% of pre-incentive fee net investment income above a specified investment return hurdle rate and a 20% incentive fee on cumulative net realized capital gains in exchange for providing advisory services to MSC Income. On and after January 29, 2025, under the Advisory Agreement, the External Investment Manager earns a 1.5% annual base management fee on MSC Income’s average total assets (including cash and cash equivalents), payable quarterly in arrears (with additional future contractual reductions based upon changes to MSC Income’s investment portfolio composition), a subordinated incentive fee on income equal to 17.5% of pre-incentive fee net investment income above a specified investment return hurdle rate, subject to a 50% / 50% catch-up feature, and a 17.5% incentive fee on cumulative net realized capital gains from January 29, 2025.

Additionally, the External Investment Manager has entered into investment management agreements with MS Private Loan Fund I, LP (the “Private Loan Fund”) and MS Private Loan Fund II, LP (the “Private Loan Fund II”), each a private investment fund with a strategy to co-invest with Main Street in Private Loan portfolio investments, pursuant to which the External Investment Manager provides investment advisory and management services to each fund in exchange for an asset-based management fee and certain incentive fees. The External Investment Manager may also advise other clients, including funds and separately managed accounts, pursuant to advisory and services agreements with such clients in exchange for asset-based and incentive fees.

The External Investment Manager earns management fees based on the assets of the funds and accounts under management and may earn incentive fees, or a carried interest, based on the performance of the funds and accounts managed. For the years ended December 31, 2024, 2023 and 2022, the External Investment Manager earned $23.9 million, $22.4 million and $21.8 million in base management fees, respectively, $13.7 million, $13.4 million and $2.5 million in incentive fees, respectively, and $0.6 million of administrative service fee income for each of the years ended December 31, 2024, 2023 and 2022.

We have entered into an agreement with the External Investment Manager to share employees in connection with its asset management business generally, and specifically for its relationship with MSC Income and its other clients. Through this agreement, we share employees with the External Investment Manager, including their related infrastructure, business relationships, management expertise and capital raising capabilities, and we allocate the related expenses to the External Investment Manager pursuant to the sharing agreement. Our total expenses for the years ended December 31, 2024, 2023 and 2022 are net of expenses allocated to the External Investment Manager of $23.1 million, $22.1 million and $13.0 million, respectively.

The total contribution of the External Investment Manager to our net investment income consists of the combination of the expenses allocated to the External Investment Manager and the dividend income earned from the External Investment Manager. For the years ended December 31, 2024, 2023, and 2022, dividends accrued by us from the External Investment Manager were $11.3 million, $11.3 million and $9.3 million, respectively. For the years ended December 31, 2024, 2023 and 2022, the total contribution of the External Investment Manager to our net investment income was $34.3 million, $33.4 million and $22.3 million, respectively.

We have received an exemptive order from the SEC permitting co-investments among us, MSC Income and other funds and clients advised by the External Investment Manager in certain negotiated transactions where co-investing would otherwise be prohibited under the 1940 Act. We have made co-investments with, and in the future intend to continue to make co-investments with MSC Income, the Private Loan Fund, the Private Loan Fund II and other funds and clients advised by the External Investment Manager, in accordance with the conditions of the order. The order requires, among other things, that we and the External Investment Manager consider whether each such investment opportunity is appropriate for us and the External Investment Manager’s advised clients, as applicable, and if it is appropriate, to propose an allocation of the investment opportunity between such parties. Because the External Investment Manager may receive performance-based fee compensation from funds and clients advised by the External Investment Manager, this may provide the Company and the External Investment Manager an incentive to allocate opportunities to other participating funds and clients instead of us. However, both we and the External Investment Manager have policies and procedures in place to manage this conflict, including oversight by the independent members of our Board of Directors. In addition to the co-investment program described above, we also co-invest in syndicated deals and other transactions where price is the only negotiated point by us and our affiliates.

BUSINESS STRATEGIES

Our principal investment objective is to maximize our portfolio’s total return by generating current income from our debt investments and current income and capital appreciation from our equity and equity-related investments, including warrants, convertible securities and other rights to acquire equity securities in a portfolio company. We have adopted the following business strategies to achieve our investment objective:

•Deliver Customized Financing Solutions in the Lower Middle Market. We offer LMM portfolio companies customized long-term debt and equity financing solutions that are tailored to the facts and circumstances of each situation. We believe our ability to provide a broad range of customized financing solutions to LMM companies sets us apart from other capital providers that focus on providing a limited number of financing alternatives. Our ability to invest across a company’s capital structure, from senior secured loans to subordinated debt to equity securities, allows us to offer LMM portfolio companies a comprehensive suite of financing options, or a “one-stop” financing solution.

•Focus on Established Companies. We generally invest in companies with established market positions, experienced management teams and proven revenue streams. We believe that those companies generally possess better risk-adjusted return profiles than newer companies that are building their management teams or are in the early stages of building a revenue base. We also believe that established companies in our targeted size range also generally provide opportunities for capital appreciation.

•Leverage the Skills and Experience of our Investment Team. Our investment team has significant experience in lending to and investing in LMM, Private Loan and Middle Market companies. The members of our investment team have broad investment backgrounds, with significant experience and long-term tenure with Main Street and prior experience at private investment funds, corporate entities with active acquisition growth strategies and activities, investment banks and other financial services companies. The expertise of our investment team in analyzing, valuing, structuring, negotiating and closing transactions should provide us with competitive advantages by allowing us to consider customized financing solutions and non-traditional or complex structures for our portfolio companies. Also, the reputation of our investment team has and should continue to enable us to generate additional revenue in the form of management and incentive fees in connection with us providing advisory services to other investment funds.

•Invest Across Multiple Companies, Industries, Regions and End Markets. We seek to maintain a portfolio of investments that is appropriately balanced among various companies, industries, geographic regions and end markets. This portfolio balance is intended to mitigate the potential effects of negative economic events for particular companies, regions, industries and end markets.

•Capitalize on Strong Transaction Sourcing Network. Our investment team seeks to leverage its extensive network of referral sources for portfolio company investments. We have developed a reputation in our marketplace as a responsive, efficient and reliable source of financing, which has created a growing stream of proprietary deal flow for us.

•Grow our Asset Management Business. Our asset management business provides us with a recurring source of income, additional income diversification from sources of income directly tied to invested capital and the opportunity for greater stockholder returns through the utilization of our existing investment expertise, strong historical track record and favorable reputation. We seek to grow our asset management business within our internally managed BDC structure in order to increase the value of this unique benefit to our stakeholders. We expect such growth to come organically through the expansion of the investment capital that we manage for third parties and the potential extension of our asset management business to new investment strategies, and potentially through mergers and acquisition activities.

•Benefit from Lower, Fixed, Long-Term Cost of Capital. The SBIC licenses held by the Funds have allowed them to issue SBA-guaranteed debentures. SBA-guaranteed debentures carry long-term fixed interest rates that are generally lower than interest rates on comparable bank loans and other debt. Because lower-cost SBA leverage is, and will continue to be, a significant part of our capital base through the Funds, our relative cost of debt capital should be lower than many of our competitors. In addition, the SBIC leverage that we receive through the Funds represents a stable, long-term component of our capital structure with proper matching of duration and cost compared to our LMM portfolio investments. We also maintain investment grade ratings from both Standard & Poor’s Ratings Services and Fitch Ratings, which provide us the opportunity and flexibility to obtain additional, attractive long-term financing options to supplement our capital structure, including the unsecured notes with fixed interest rates we issue.

INVESTMENT CRITERIA

Our investment team has identified the following investment criteria that it believes are important in evaluating prospective portfolio companies. Our investment team uses these criteria in evaluating investment opportunities. However, not all of these criteria have been, or will be, met in connection with each of our investments:

•Proven Management Team with Meaningful Equity Stake. We look for operationally-oriented management with direct industry experience and a successful track record. In addition, we expect the management team of each LMM portfolio company to have meaningful equity ownership in the portfolio company to better align our respective economic interests. We believe management teams with these attributes are more likely to manage the companies in a manner that both protects our debt investment and enhances the value of our equity investment.

•Established Companies with Positive Cash Flow. We seek to invest in established companies with sound historical financial performance. We primarily pursue investments in LMM companies that have historically generated EBITDA of $3 million to $20 million and commensurate levels of free cash flow. We also pursue investments in Private Loan companies that have historically generated annual EBITDA of $7.5 million to $50 million. We generally do not invest in start-up companies or companies with speculative business plans.

•Defensible Competitive Advantages/Favorable Industry Position. We primarily focus on companies having competitive advantages in their respective markets and/or operating in industries with barriers to entry, which may help to protect their market position and profitability.

•Exit Alternatives. We exit our debt investments primarily through the repayment of our investment from internally generated cash flow of the portfolio company and/or a refinancing. In addition, we seek to invest in companies whose business models and expected future cash flows may provide alternate methods of repaying our investment, such as through a strategic acquisition by other industry participants or a recapitalization.

INVESTMENT PORTFOLIO

Our LMM portfolio investments primarily consist of secured debt, direct equity investments and equity warrants in privately held, LMM companies based in the United States. Our Private Loan portfolio investments primarily consist of investments in debt securities that are primarily originated directly by us, or to a lesser extent, through our 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 in a company owned by or in the process of being acquired by a private equity fund. Our Middle Market portfolio investments are generally debt investments in companies owned by private equity funds that were originally issued through a syndication financing process. We have generally stopped making new Middle Market investments and expect the size of our Middle Market investment portfolio to continue to decline in future periods as existing Middle Market investments are repaid or sold. Our Other Portfolio investments primarily consist of investments that are not consistent with the typical profiles for our LMM, Private Loan and Middle Market portfolio investments, including investments which may be managed by third parties. In our Other Portfolio, we may incur indirect fees and expenses in connection with investments managed by third parties, such as investments in other investment companies or private funds.

Debt Investments

Historically, we have made LMM debt investments principally in the form of single tranche debt. Single tranche debt financing involves issuing one debt security that blends the risk and return profiles of both first lien secured and subordinated debt. We believe that single tranche debt is more appropriate for many LMM companies given their size in order to reduce structural complexity and potential conflicts among creditors.

Our LMM debt investments generally have a term of five to seven years from the original investment date, with limited required amortization prior to maturity, and provide for monthly or quarterly payment of interest at interest rates generally between 10% and 14% per annum, payable currently in cash on either a fixed or floating rate basis. The LMM debt investments with floating interest rates will generally bear interest at the Secured Overnight Financing Rate (“SOFR”) or the Prime rate typically subject to a contractual minimum interest rate (an “interest rate floor”), plus a margin. In addition, certain LMM debt investments may have a form of interest that is not paid currently but is accrued and added to the loan balance and paid at maturity. We refer to this form of interest as payment-in-kind, or PIK, interest. We typically structure our LMM debt investments with the maximum seniority and collateral that we can reasonably obtain while seeking to achieve our total return target. In most cases, our LMM debt investment will be collateralized by a first priority lien on substantially all the assets of the portfolio company. In addition to seeking a senior lien position in the capital structure of our LMM portfolio companies, we seek to limit the downside potential of our LMM debt investments by negotiating covenants that are designed to protect our LMM debt investments while affording our portfolio companies as much flexibility in managing their businesses as is reasonable. Such restrictions may include affirmative and negative covenants, default penalties, lien protection, change of control or change of management provisions, key-man life insurance, guarantees, equity pledges, personal guaranties, where appropriate, and put rights. In addition, we typically seek board representation or observation rights in all of our LMM portfolio companies.

While we will continue to focus our LMM debt investments primarily on single tranche debt investments, we may structure some of our debt investments as mezzanine loans. These mezzanine loans would be primarily junior secured or unsecured, subordinated loans that would provide for relatively high interest rates, payable currently in cash, and would provide us with significant interest income. These mezzanine loans would afford us the additional opportunity for income and gains through PIK interest and equity warrants and other similar equity instruments issued in conjunction with these mezzanine loans. These loans typically would have interest-only payments in the early years, with amortization of principal deferred to the later years of the mezzanine loan term. Typically, these mezzanine loans would have maturities of three to five years. We would generally target interest rates of 12% to 14%, payable currently in cash, for our mezzanine loan investments with higher targeted total returns from equity warrants or PIK interest.

The debt investments in our Private Loan portfolio have rights and protections that are similar to those in our LMM debt investments, which may include affirmative and negative covenants, default penalties, lien protection, change of control provisions, guarantees and equity pledges. Our Private Loan portfolio debt investments are generally secured by a first priority lien and typically have a term of between three and seven years from the original investment date. Our Private Loan debt investments generally have floating interest rates at SOFR or Prime rate typically subject to an interest rate floor, plus a margin.

Our Middle Market 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 and seven years from the original investment date. The debt investments in our Middle Market portfolio usually have rights and protections that are similar to those in our LMM and Private Loan debt investments. The Middle Market debt investments generally have floating interest rates at SOFR or Prime rate typically subject to an interest rate floor, plus a margin.

Direct Equity Investments

We also seek to make direct equity investments to align our interests with key management and stockholders of our LMM portfolio companies, and to allow for participation in the appreciation in the equity values of our LMM portfolio companies. We usually make our direct equity investments in connection with debt investments in our LMM portfolio companies. In addition, we may have both equity warrants and direct equity positions in some of our LMM portfolio companies. We seek to maintain fully diluted equity positions in our LMM portfolio companies of 5% to 50%, and may have controlling equity interests in some instances. We have a value orientation toward our direct equity investments and have traditionally been able to purchase our equity investments at reasonable valuations. We will also have, from time to time, the opportunity to co-invest with the private equity funds in the equity securities of our Private Loan portfolio companies. The equity co-investment aligns our interests with those of the private equity fund and provides us with the opportunity to benefit from appreciation in the equity values of our Private Loan portfolio companies.

Warrants

In connection with our LMM debt investments, we occasionally receive equity warrants to establish or increase our equity interest in the portfolio company. Warrants that we receive in connection with a debt investment typically require only a nominal cost to exercise, and thus, as a portfolio company appreciates in value, we may achieve additional investment return from this equity interest. We typically structure the warrants to provide provisions protecting our rights as a minority-interest holder, as well as secured or unsecured put rights, or rights to sell such securities back to the portfolio company, upon the occurrence of specified events. In certain cases, we also may obtain registration rights in connection with these equity interests, which may include demand and “piggyback” registration rights.

INVESTMENT PROCESS

Our management team’s investment committee is responsible for all aspects of our investment processes. The current members of our investment committee are Dwayne L. Hyzak, our Chief Executive Officer, David Magdol, our President and Chief Investment Officer, and Vincent D. Foster, the Chairman of our Board of Directors.

The investment processes for portfolio investments are outlined below. Our investment strategy involves a “team” approach, whereby potential transactions are screened by several members of our investment team before being presented to the investment committee. Our investment committee meets on an as-needed basis depending on transaction volume. We generally categorize our investment process into seven distinct stages:

Deal Generation/Origination

Deal generation and origination is maximized through long-standing and extensive relationships with industry contacts, brokers, commercial and investment bankers, entrepreneurs, service providers such as lawyers, financial advisors and accountants, and current and former portfolio companies and investors. Our investment team has developed a reputation as a knowledgeable, reliable and active source of capital and assistance in these markets.

Screening

During the screening process, if a transaction initially meets our investment criteria, we will perform preliminary due diligence, taking into consideration some or all of the following information:

•a comprehensive financial model based on quantitative analysis of historical financial performance, projections and pro forma adjustments to determine the estimated internal rate of return;

•a brief industry and market analysis;

•direct industry expertise imported from other portfolio companies or investors;

•preliminary qualitative analysis of the management team’s competencies and backgrounds;

•potential investment structures and pricing terms; and

•regulatory compliance.

Upon successful screening of a proposed transaction, the investment team makes a recommendation to our investment committee. If our investment committee concurs with moving forward on the proposed transaction, we typically issue a non-binding term sheet or letter of intent to the company.

Term Sheet

For proposed transactions, the non-binding term sheet or letter of intent will include the key economic terms based upon our analysis performed during the screening process, as well as a proposed timeline and our qualitative expectation for the transaction. While the term sheet or letter of intent for investments is non-binding, we typically receive an expense deposit in order to move the transaction to the due diligence phase. Upon execution of a term sheet or letter of intent, we begin our formal due diligence process.

Due Diligence

Due diligence on a proposed LMM investment is performed by a minimum of three of our investment professionals, whom we refer to collectively as the investment team, and certain external resources, who together conduct due diligence to understand the relationships among the prospective portfolio company’s business plan, operations and financial performance. Our LMM due diligence review includes some or all of the following:

•site visits with management and key personnel;

•detailed review of historical and projected financial statements;

•operational reviews and analysis;

•interviews with customers and suppliers;

•detailed evaluation of company management, including background checks;

•review of material contracts;

•in-depth industry, market and strategy analysis;

•regulatory compliance analysis; and

•review by legal, environmental or other consultants, if applicable.

Due diligence on a proposed Private Loan investment is generally performed on materials and information obtained from certain external resources and assessed internally by a minimum of three of our investment professionals, who work to understand the relationships among the prospective portfolio company’s business plan, operations and financial performance using the accumulated due diligence information. Our typical Private Loan due diligence review includes some or all of the following:

•detailed review of historical and projected financial statements

•site visits or other discussions with management and key personnel;

•in-depth industry, market, operational and strategy analysis;

•regulatory compliance analysis; and

•detailed review of the company’s management team and their capabilities.

During the due diligence process, significant attention is given to sensitivity analyses and how the company might be expected to perform given downside, base-case and upside scenarios. In certain cases, we may decide not to make an investment based on the results of the diligence process.

Document and Close

Upon completion of a satisfactory due diligence review of a proposed LMM portfolio investment, the investment team presents the findings and a recommendation to our investment committee. The presentation contains information which can include, but is not limited to, the following:

•company history and overview;

•transaction overview, history and rationale, including an analysis of transaction strengths and risks;

•analysis of key customers and suppliers and key contracts;

•a working capital analysis;

•an analysis of the company’s business strategy;

•a management and key equity investor background check and assessment;

•third-party accounting, legal, environmental or other due diligence findings;

•investment structure and expected returns;

•anticipated sources of repayment and potential exit strategies;

•pro forma capitalization and ownership;

•an analysis of historical financial results and key financial ratios;

•sensitivities to management’s financial projections;

•regulatory compliance analysis findings; and

•detailed reconciliations of historical to pro forma results.

Upon completion of a satisfactory due diligence review of a proposed Private Loan portfolio investment, the investment team presents the findings and a recommendation to our investment committee. The presentation contains information which can include, but is not limited to, the following:

•company history and overview;

•transaction overview, history and rationale, including an analysis of transaction strengths and risks;

•overview and history of the private equity fund sponsor as the company’s equity owner;

•analysis of key customers and suppliers;

•an analysis of the company’s business strategy;

•investment structure and expected returns;

•anticipated sources of repayment and potential exit strategies;

•pro forma capitalization and ownership;

•regulatory compliance analysis findings; and

•an analysis of historical financial results and key financial ratios.

If any adjustments to the transaction terms or structures are proposed by the investment committee, such changes are made and applicable analyses are updated prior to approval of the transaction. Approval for the transaction must be made by the affirmative vote from a majority of the members of the investment committee, with the committee member managing the transaction, if any, abstaining from the vote. Upon receipt of transaction approval, the investment team will re-confirm regulatory compliance, process and finalize all required legal documents, and fund the investment.

Post-Investment

We continuously monitor the status and progress of the portfolio companies. We generally offer managerial assistance to our portfolio companies, giving them access to our investment experience, direct industry expertise and contacts. The same investment team that was involved in the investment process will continue its involvement in the portfolio company post-investment. This provides for continuity of knowledge and allows the investment team to maintain a strong business relationship with key management of our portfolio companies for post-investment assistance and monitoring purposes.

As part of the monitoring process of LMM portfolio investments, the investment team will analyze monthly and quarterly financial statements versus the previous periods and year, review financial projections, meet and discuss issues or opportunities with management, attend board meetings and review all compliance certificates and covenants. While we maintain limited involvement in the ordinary course operations of our LMM portfolio companies, we maintain a higher level of involvement in non-ordinary course financing or strategic activities and any non-performing scenarios.

As part of the monitoring process of our Private Loan and Middle Market portfolio investments, the investment team will analyze monthly and quarterly financial statements versus the previous periods and year, review financial projections and review all compliance certificates and covenants. Depending upon the nature of our Private Loan and Middle Market portfolio investments, our investment team may also attend board meetings, and meet and discuss issues or opportunities with the portfolio company’s management team or private equity owners, however, due to the nature of our “lender only” relationship with these Private Loan and Middle Market companies in comparison to our LMM portfolio companies, is is not practical to have as much direct management interface.

We utilize an internally developed investment rating system to rate the performance of each LMM, Private Loan and Middle Market portfolio company and to monitor our expected level of returns on each of our LMM, Private Loan and Middle Market investments in relation to our expectations for the portfolio company. The investment rating system takes into consideration various factors, including, but not limited to, each investment’s expected level of returns, the collectability of our debt investments and the ability to receive a return of the invested capital in our equity investments, comparisons to competitors and other industry participants, the portfolio company’s future outlook and other factors that are deemed to be significant to the portfolio company.

Exit Strategies/Refinancing

While we generally exit most investments through the refinancing or repayment of our debt and redemption or sale of our equity positions, we typically assist our LMM portfolio companies in developing and planning exit opportunities, including any sale or merger of our portfolio companies. We may also assist in the structure, timing, execution and transition of the exit strategy. The refinancing or repayment of Private Loan investments and Middle Market debt investments typically do not require our assistance due to the additional resources available to these larger Private Loan and Middle Market companies.

DETERMINATION OF NET ASSET VALUE AND INVESTMENT PORTFOLIO VALUATION PROCESS

We determine the net asset value (“NAV”) per share of our common stock on a quarterly basis. The NAV per share is equal to our total assets minus total liabilities divided by the total number of shares of common stock outstanding.

We are required to report our investments at fair value. As a result, the most significant determination inherent in the preparation of our consolidated financial statements is the valuation of our Investment Portfolio and the related amounts of unrealized appreciation and depreciation. We follow the provisions of the Financial Accounting Standards Board Accounting Standards Codification (“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 us 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.

We determine in good faith the fair value of our Investment Portfolio pursuant to a valuation policy in accordance with ASC 820 and a valuation process approved by our Board of Directors and in accordance with the 1940 Act. Our valuation policies and processes are intended to provide a consistent basis for determining the fair value of our Investment Portfolio. See Note B.1. — Summary of Significant Accounting Policies — Valuation of the Investment Portfolio included in Item 8. Consolidated Financial Statements and Supplementary Data of this Annual Report on Form 10-K for a detailed discussion of our Investment Portfolio valuation process and procedures.

Due to the inherent uncertainty in the valuation process, our determination of fair value for our 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. We determine the fair value of each individual investment and record changes in fair value as unrealized appreciation or depreciation.

The 1940 Act requires valuation of a portfolio security at “market value” if market quotations for the security are “readily available.” Portfolio securities for which market quotations are not readily available must be valued at fair value as determined in good faith by the board of directors. 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.

Our Board of Directors has approved policies and procedures pursuant to Rule 2a-5 (the “Valuation Procedures”) and designated a group of our executive officers to serve as the Board’s valuation designee thereunder (the “Valuation Committee”). Pursuant to the Valuation Procedures, we undertake a multi-step process each quarter in connection with determining the fair value of our investments.

The following outlines our valuation process as established under the Valuation Procedures:

•Our quarterly process begins with an initial valuation of each portfolio investment performed by the valuation team consisting of several professionals who apply the appropriate valuation methodology depending on the type of investment.

•Each valuation model is then reviewed by the investment team responsible for monitoring the portfolio investment for accuracy, with any recommended changes reviewed by the valuation team.

•Updated valuation conclusions are then reviewed by and discussed with the Valuation Committee at quarterly valuation meetings. Valuation meetings are generally attended by the Valuation Committee, the valuation team, members of the investment team responsible for each investment and members of the compliance team. Valuation models and valuation conclusions are adjusted as necessary following such meetings.

•A nationally recognized independent financial advisory services firm analyzes and provides observations, recommendations and an assurance certification regarding the determinations of the fair value for the majority of our portfolio companies on a rotational basis.

•After incorporating commentary by the Valuation Committee and review of recommendations provided by the independent financial advisory services firm, valuation results are finalized and approved by the Valuation Committee.

•The Board of Directors oversees the process through its Audit Committee in accordance with Rule 2a-5 pursuant to the Valuation Procedures.

Determination of fair value involves subjective judgments and estimates. The notes to our consolidated financial statements refer to the uncertainty with respect to the possible effect of such valuations, and any change in such valuations, on our financial results and financial condition.

COMPETITION

We compete for investments with a number of investment funds (including private equity funds, mezzanine funds, BDCs and SBICs), as well as traditional financial services companies such as commercial banks and other sources of financing. Many of the entities that compete with us are larger and have more resources available to them. We believe we are able to be competitive with these entities primarily on the basis of our focus on the underserved companies described in our LMM investment strategy and the less competitive nature of the market for companies described in our Private Loan investment strategy, the experience and contacts of our management team, our responsive and efficient investment analysis and decision-making processes, our comprehensive suite of customized financing solutions and the investment terms we offer.

We believe that some of our competitors make senior secured loans, junior secured loans and subordinated debt investments with interest rates and returns that are comparable to or lower than the rates and returns that we target. Therefore, we do not seek to compete primarily on the interest rates and returns that we offer to potential portfolio companies. For additional information concerning the competitive risks we face, see Item 1A. Risk Factors — Risks Related to Our Business and Structure — We face increasing competition for investment opportunities.

HUMAN CAPITAL

Our employees are vital to our success as a principal investment firm. As a human-capital intensive business, the long-term success of our company depends on our people. We strive to attract, develop and retain our employees by offering unique employment opportunities, superior advancement and promotion opportunities, attractive compensation and benefit structures and a close-knit culture. The departure of our key investment and other personnel could cause our operating results to suffer.

Our LMM business depends heavily on the business owners and management teams of our portfolio companies and their respective employees, contractors and service providers. In our investment process for LMM portfolio investments, the analysis of these individuals is a critical part of our overall investment underwriting process and as a result we carefully review the qualifications and experience of the portfolio company’s business owners and management team and their employment practices. We strive to partner with business owners and management teams whose business practices reflect our core values.

We strive to recruit talented and driven individuals who share our values. We have competitive programs dedicated to attracting and retaining new talent and enhancing the skills of our employees. Our recruiting efforts utilize strong relationships with a variety of sources from which we recruit. Among other opportunities, we offer selected students investment analyst internships, which are expected to lead to permanent roles for high performing and high potential interns. Through our internship program, individuals who want to become investment analysts have the opportunity to see the full investment process from origination to closing, as well as post-closing portfolio management activities. We routinely recruit from within, promoting current employees who have shown the technical ability, attitude, interest and the initiative to take on greater responsibility.

We have designed a compensation structure, including an array of benefit plans and programs, that we believe is attractive to our current and prospective employees. We also offer formal and informal training and mentorship programs that provide employees with access to senior level executives. Through our annual goal setting and performance review processes, our employees are annually evaluated by supervisors and our senior management team to ensure employees continue to develop and advance as expected. We are committed to having a diverse workforce, and an inclusive work environment is a natural extension of our culture. We also maintain a Women’s Initiative that provides employees with opportunities to network internally at Main Street and externally with other women in the financial services industry. Our employees have access to several programs designed to enable our employees to balance work, family and family-related situations including flexible working arrangements and parental leave for birth and adoption placement. We are committed to creating and maintaining an atmosphere where all employees feel welcomed, valued, respected and heard so that they feel motivated and encouraged to contribute fully to their careers, our company and our communities.

We seek to maintain a close-knit culture, which we believe is an important factor in employee retention, which is reinforced by our Community Building Committee. Our Community Building Committee, which is composed of a substantial cross section of employees across our organization, develops programs and initiatives that promote an open and inclusive atmosphere and encourage employee outreach with our community, in each case based upon feedback received from our employees. Initiatives generated by our Community Building Committee include employee well-being and engagement activities along with volunteer and donation opportunities with local charitable organizations. We encourage you to visit our website for more information about charitable organizations receiving our ongoing support. Nothing on our website, however, shall be deemed incorporated by reference into this Annual Report on Form 10-K.

We monitor and evaluate various turnover and attrition metrics throughout our management team. Our annualized voluntary turnover is relatively low, a record which we attribute to our strong corporate culture, commitment to career development and attractive compensation and benefit programs. For additional information concerning the competitive risks we face, see Item 1A. Risk Factors — Risks Related to Our Business and Structure — Our success depends on attracting and retaining qualified personnel in a competitive environment.

As of December 31, 2024, we had 104 employees, 58 of whom we characterize as investment and portfolio management professionals, and the others include operations professionals and administrative staff. None of our employees are represented by a collective bargaining agreement. As necessary, we will hire additional investment professionals and administrative personnel. All but three of our employees are located in our Houston, Texas office.

REGULATION

Regulation as a Business Development Company

We have elected to be regulated as a BDC under the 1940 Act. The 1940 Act contains prohibitions and restrictions relating to transactions between BDCs and their affiliates, principal underwriters and affiliates of those affiliates or underwriters. The 1940 Act requires that a majority of the members of the board of directors of a BDC be persons other than “interested persons,” as that term is defined in the 1940 Act. In addition, the 1940 Act provides that we may not change the nature of our business so as to cease to be, or to withdraw our election as, a BDC unless approved by a majority of our outstanding voting securities.

The 1940 Act defines “a majority of the outstanding voting securities” as the lesser of (i) 67% or more of the voting securities present at a meeting if the holders of more than 50% of our outstanding voting securities are present or represented by proxy or (ii) more than 50% of our outstanding voting securities.

Qualifying Assets

Under the 1940 Act, a BDC may not acquire any asset other than assets of the type listed in Section 55(a) of the 1940 Act, which are referred to as qualifying assets, unless, at the time the acquisition is made, qualifying assets represent at least 70% of the company’s total assets. The principal categories of qualifying assets relevant to our business are any of the following:

(1)Securities purchased in transactions not involving any public offering from the issuer of such securities, which issuer (subject to certain limited exceptions) is an eligible portfolio company (as defined below), or from any person who is, or has been during the preceding 13 months, an affiliated person of an eligible portfolio company, or from any other person, subject to such rules as may be prescribed by the SEC.

(2)Securities of any eligible portfolio company that we control.

(3)Securities purchased in a private transaction from a U.S. issuer that is not an investment company or from an affiliated person of the issuer, or in transactions incident thereto, if the issuer is in bankruptcy and subject to reorganization or if the issuer, immediately prior to the purchase of its securities was unable to meet its obligations as they came due without material assistance other than conventional lending or financing arrangements.

(4)Securities of an eligible portfolio company purchased from any person in a private transaction if there is no ready market for such securities and we already own 60% of the outstanding equity of the eligible portfolio company.

(5)Securities received in exchange for or distributed on or with respect to securities described in (1) through (4) above, or pursuant to the exercise of warrants or rights relating to such securities.

(6)Cash, cash equivalents, U.S. government securities or high-quality debt securities maturing in one year or less from the time of investment.

In addition, a BDC must have been organized and have its principal place of business in the United States and must be operated for the purpose of making investments in the types of securities described in (1), (2) or (3) above.

An eligible portfolio company is defined in the 1940 Act as any issuer which:

(a)is organized under the laws of, and has its principal place of business in, the United States;

(b)is not an investment company (other than a small business investment company wholly-owned by the BDC) or a company that would be an investment company but for certain exclusions under the 1940 Act; and

(c)satisfies any of the following:

(i)does not have any class of securities that is traded on a national securities exchange or has a class of securities listed on a national securities exchange but has an aggregate market value of outstanding voting and non-voting common equity of less than $250 million;

(ii)is controlled by a BDC or a group of companies including a BDC and the BDC has an affiliated person who is a director of the eligible portfolio company; or

(iii)is a small and solvent company having total assets of not more than $4 million and capital and surplus of not less than $2 million.

Managerial Assistance to Portfolio Companies

As noted above, a BDC must be operated for the purpose of making investments in the type of securities described in (1), (2) or (3) above under the heading entitled “— Qualifying Assets.” In addition, BDCs must generally offer to make available to such issuer of the securities (other than small and solvent companies described above) significant managerial assistance. Making available managerial assistance means, among other things, any arrangement whereby the BDC, through its directors, officers or employees, offers to provide, and, if accepted, does so provide, significant guidance and counsel concerning the management, operations or business objectives and policies of a portfolio company. However, if a BDC purchases securities in conjunction with one or more other persons acting together, one of the other persons in the group may make available such significant managerial assistance on behalf of all investors in the group.

Temporary Investments

Pending investment in “qualifying assets,” as described above, our investments may consist of cash, cash equivalents, U.S. government securities and high-quality debt securities maturing in one year or less from time of investment therein, so that 70% of our assets are qualifying assets.

Prior to 2018 legislation that modified the asset coverage requirements of the 1940 Act, we were permitted, as a BDC, to issue senior securities only in amounts such that our asset coverage, or BDC asset coverage ratio, as defined in the 1940 Act, equals at least 200% of all debt and/or senior stock immediately after each such issuance. However, 2018 legislation modified the 1940 Act by allowing a BDC to increase the maximum amount of leverage it may incur such that a BDC’s asset coverage ratio could be reduced from an asset coverage ratio of 200% to an asset coverage ratio of 150%, if certain requirements are met. In May 2022, our stockholders approved the application of the reduced BDC asset coverage ratio. As a result, the BDC asset coverage ratio applicable to us decreased from 200% to 150% effective May 3, 2022.

We have received exemptive relief from the SEC to permit us to exclude the SBA-guaranteed debentures of the Funds from our 150% asset coverage test under the 1940 Act. As such, our ratio of total consolidated assets to outstanding indebtedness may be less than 150%. This provides us with increased investment flexibility but also increases our risks related to leverage.

In addition, while any senior securities remain outstanding (other than senior securities representing indebtedness issued in consideration of a privately arranged loan which is not intended to be publicly distributed), we must generally include provisions in the documents governing new senior securities to prohibit any cash distribution to our stockholders or the repurchase of such securities or shares unless we meet the applicable asset coverage ratios at the time of the distribution or repurchase. We may also borrow amounts up to 5% of the value of our total assets for temporary or emergency purposes without regard to asset coverage with such borrowings not constituting senior securities for purposes of the asset coverage ratio requirements of the 1940 Act. A loan is presumed to be for temporary purposes if it is repaid within sixty days and not extended or renewed. For a discussion of the risks associated with leverage, see Item 1A. Risk Factors — Risks Related to Leverage, including, without limitation, — Because we borrow money, the potential for gain or loss on amounts invested in us is magnified and may increase the risk of investing in us.

Common Stock

We are not generally able to issue and sell our common stock at a price below NAV per share. We may, however, sell our common stock, warrants, options or rights to acquire our common stock, at a price below the current NAV of the common stock if our Board of Directors determines that such sale is in our best interests and that of our stockholders, and our stockholders approve such sale. In any such case, the price at which our securities are to be issued and sold may not be less than a price which, in the determination of our Board of Directors, closely approximates the market value of such securities (less any distributing commission or discount). We did not seek stockholder authorization to sell shares of our common stock below the then current NAV per share of our common stock at our 2024 Annual Meeting of Stockholders, and have not sought such stockholder authorization since 2012, because our common stock price had been trading significantly above the NAV per share of our common stock since 2011. Our stockholders have previously approved a proposal that authorizes us to issue securities to subscribe to, convert to, or purchase shares of our common stock in one or more offerings. We may also make rights offerings to our stockholders at prices per share less than the NAV per share, subject to applicable requirements of the 1940 Act. See Item 1A. Risk Factors — Risks Related to our Securities — Stockholders may incur dilution if we sell shares of our common stock in one or more offerings at prices below the then current NAV per share of our common stock or issue securities to subscribe to, convert to or purchase shares of our common stock.

Code of Ethics

We have adopted a code of ethics pursuant to Rule 17j-1 under the 1940 Act that establishes procedures for personal investments and restricts certain personal securities transactions. Personnel subject to the code may invest in securities for their personal investment accounts, including securities that may be purchased or held by us, so long as such investments are made in accordance with the code’s requirements. The code of ethics is available on the EDGAR Database on the SEC’s website athttp://www.sec.gov.

Proxy Voting Policies and Procedures

We vote proxies relating to our portfolio securities in a manner in which we believe is consistent with the best interest of our stockholders. We review on a case-by-case basis each proposal submitted to a stockholder vote to determine its impact on the portfolio securities held by us. Although we generally vote against proposals that we expect would have a negative impact on our portfolio securities, we may vote for such a proposal if there exists compelling long-term reasons to do so.

Our proxy voting decisions are made by the investment team which is responsible for monitoring each of our investments. To ensure that our vote is not the product of a conflict of interest, we require that anyone involved in the decision-making process discloses to our chief compliance officer any potential conflict regarding a proxy vote of which he or she is aware.

Stockholders may obtain information, without charge, regarding how we voted proxies with respect to our portfolio securities by making a written request for proxy voting information to: Chief Compliance Officer, 1300 Post Oak Boulevard, 8 th Floor, Houston, Texas 77056.

Other 1940 Act Regulations

We are also prohibited under the 1940 Act from knowingly participating in certain transactions with our affiliates without the prior approval of our Board of Directors who are not interested persons and, in some cases, prior approval by the SEC.

We are required to provide and maintain a bond issued by a reputable fidelity insurance company to protect us against larceny and embezzlement. Furthermore, as a BDC, we are prohibited from protecting any director or officer against any liability to us or our stockholders arising from willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of such person’s office.

We are required to adopt and implement written policies and procedures reasonably designed to prevent violation of the federal securities laws, review these policies and procedures no less frequently than annually for their adequacy and the effectiveness of their implementation, and to designate a chief compliance officer to be responsible for administering the policies and procedures.

We may be periodically examined by the SEC for compliance with the 1940 Act.

Small Business Investment Company Regulations

Each of the Funds is licensed by the SBA to operate as a SBIC under Section 301(c) of the Small Business Investment Act of 1958. MSMF obtained its SBIC license in 2002 and MSC III obtained its license in 2016.

SBICs are designed to stimulate the flow of private capital to eligible small businesses. Under SBIC regulations, SBICs may make loans to eligible small businesses, invest in the equity securities of such businesses and provide them with consulting and advisory services. Each of the Funds has typically invested in secured debt, acquired warrants and/or made equity investments in qualifying small businesses.

The Funds are subject to regulation and oversight by the SBA, including requirements with respect to reporting financial information, such as the extent of capital impairment if applicable, on a regular basis and annual examinations conducted by the SBA. The SBA, as a creditor, will have a superior claim to the Funds’ assets over our securities holders in the event the Funds are liquidated or the SBA exercises its remedies under the SBA-guaranteed debentures issued by the Funds upon an event of default.

Under present SBIC regulations, eligible small businesses generally include businesses that (together with their affiliates) have a tangible net worth not exceeding $24 million or have average annual net income after U.S. federal income taxes not exceeding $8 million (average net income to be computed without benefit of any carryover loss) for the two most recent fiscal years. In addition, an SBIC must devote 25% of its investment activity to “smaller enterprises” as defined by the SBA. A smaller enterprise generally includes businesses that have a tangible net worth not exceeding $6 million and have average annual net income after U.S. federal income taxes not exceeding $2 million (average net income to be computed without benefit of any net carryover loss) for the two most recent fiscal years. SBIC regulations also provide alternative size standard criteria to determine eligibility for designation as an eligible small business or smaller enterprise, which criteria depend on the primary industry in which the business is engaged and are based on such factors as the number of employees and gross revenue. However, once an SBIC has invested in a company, it generally may continue to make follow-on investments in the company, regardless of the size of the portfolio company at the time of the follow-on investment, up to the time of the portfolio company’s initial public offering.

The SBA prohibits an SBIC from providing funds to small businesses for certain purposes, such as relending and investment outside the United States, to businesses engaged in certain prohibited industries, and to certain “passive” (non-operating) companies. In addition, without prior SBA approval, an SBIC may not invest an amount equal to more than 30% of the SBIC’s regulatory capital, as defined by the SBA, in any one portfolio company and its affiliates.

The SBA places certain limitations on the financing terms of investments by SBICs in portfolio companies (such as limiting the permissible interest rate on debt securities held by an SBIC in a portfolio company). Included in such limitations are SBIC regulations which allow an SBIC to exercise control over a small business for a period of seven years from the date on which the SBIC initially acquires its control position. This control period may be extended for an additional period of time with the SBA’s prior written approval.

The SBA restricts the ability of an SBIC to lend money to any of its officers, directors and employees or to invest in affiliates thereof. The SBA also prohibits, without prior SBA approval, a “change of control” of an SBIC or transfers that would result in any person (or a group of persons acting in concert) owning 10% or more of a class of equity of a licensed SBIC. A “change of control” is any event which would result in the transfer of the power, direct or indirect, to direct the management and policies of an SBIC, whether through ownership, contractual arrangements or otherwise.

The SBIC licenses allow the Funds to incur leverage by issuing SBA-guaranteed debentures, subject to the issuance of a capital commitment and certain approvals by the SBA and customary procedures. SBA-guaranteed debentures carry long-term fixed rates that are generally lower than rates on comparable bank and other debt. Under applicable regulations, an SBIC may generally have outstanding debentures guaranteed by the SBA in amounts up to twice the amount of the privately raised funds of the SBIC. Debentures guaranteed by the SBA have a maturity of ten years, require semiannual payments of interest, do not require any principal payments prior to maturity, and are not subject to prepayment penalties. As of December 31, 2024, we, through the Funds, had $350.0 million of outstanding SBA-guaranteed debentures, which had an annual weighted-average interest rate of 3.3%.

SBICs must invest idle funds that are not being used to make loans in investments permitted under SBIC regulations in the following limited types of securities: (i) direct obligations of, or obligations guaranteed as to principal and interest by, the United States government, which mature within 15 months from the date of the investment; (ii) repurchase agreements with federally insured institutions with a maturity of seven days or less (and the securities underlying the repurchase obligations must be direct obligations of or guaranteed by the federal government); (iii) mutual funds, securities or other instruments that exclusively consist of, or represented pooled assets of investments described in (i) and (ii) above; (iv) certificates of deposit with a maturity of one year or less, issued by a federally insured institution; (v) a deposit account in a federally insured institution that is subject to a withdrawal restriction of one year or less; (vi) a checking account in a federally insured institution; or (vii) a reasonable petty cash fund.

SBICs are periodically examined and audited by the SBA’s staff to determine their compliance with SBIC regulations and are periodically required to file certain financial information and other documents with the SBA.

Neither the SBA nor the U.S. government or any of its agencies or officers has approved any ownership interest to be issued by us or any obligation that we or any of our subsidiaries may incur.

Securities Exchange Act of 1934 and Sarbanes-Oxley Act Compliance

We are subject to the reporting and disclosure requirements of the Securities Exchange Act of 1934 (the “Exchange Act”), including the filing of quarterly, annual and current reports, proxy statements and other required items. In addition, we are subject to the Sarbanes-Oxley Act of 2002, which imposes a wide variety of regulatory requirements on publicly-held companies and their insiders. For example:

•pursuant to Rule 13a-14 of the Exchange Act, our Chief Executive Officer and Chief Financial Officer are required to certify the accuracy of the consolidated financial statements contained in our periodic reports;

•pursuant to Item 307 of Regulation S-K, our periodic reports are required to disclose our conclusions about the effectiveness of our disclosure controls and procedures;

•pursuant to Rule 13a-15 of the Exchange Act, our management is required to prepare a report regarding its assessment of our internal control over financial reporting, and our independent registered public accounting firm separately audits our internal control over financial reporting; and

•pursuant to Item 308 of Regulation S-K and Rule 13a-15 of the Exchange Act, our periodic reports must disclose whether there were significant changes in our internal control over financial reporting or in other factors that could significantly affect these controls subsequent to the date of their evaluation, including any corrective actions with regard to significant deficiencies and material weaknesses.

The New York Stock Exchange Corporate Governance Regulations

The New York Stock Exchange (“NYSE”) has adopted corporate governance regulations that listed companies must comply with. We believe we are in compliance with such corporate governance listing standards. We intend to monitor our compliance with all future listing standards and to take all necessary actions to ensure that we stay in compliance.

Investment Adviser Regulations

The External Investment Manager, which is wholly-owned by us, is subject to regulation under the Investment Advisers Act of 1940, as amended (the “Advisers Act”). The Advisers Act establishes, among other things, recordkeeping and reporting requirements, disclosure requirements, limitations on transactions between the adviser’s account and an advisory client’s account, limitations on transactions between the accounts of advisory clients, and general anti-fraud prohibitions. The External Investment Manager may be examined by the SEC from time to time for compliance with the Advisers Act.

Taxation as a Regulated Investment Company

MSCC has elected to be treated for U.S. federal income tax purposes as a RIC under Subchapter M of the Code. MSCC’s taxable income includes the taxable income generated by MSCC and certain of its subsidiaries, including the Funds, which are treated as disregarded entities for tax purposes. As a RIC, MSCC generally will not pay corporate-level U.S. federal income taxes on any income that we distribute to our stockholders as dividends. To qualify as a RIC, we must, among other things, meet certain source-of-income and asset diversification requirements (as described below). In addition, in order to obtain RIC tax treatment, we must distribute to our stockholders, for each taxable year, at least 90% of our “investment company taxable income,” which is generally our net ordinary taxable income plus the excess of realized net short-term capital gains over realized net long-term capital losses, and 90% of our tax-exempt income (the “Annual Distribution Requirement”). 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 12 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.

For any taxable year in which we qualify as a RIC and satisfy the Annual Distribution Requirement, we will not be subject to U.S. federal income tax on the portion of our income or capital gains we distribute (or are deemed to distribute) to stockholders. We will be subject to U.S. federal income tax at the regular corporate rates on any income or capital gains not distributed (or deemed distributed) to our stockholders.

We are subject to a 4% non-deductible U.S. federal excise tax on certain undistributed income unless we distribute in a timely manner an amount at least equal to the sum of (1) 98% of our net ordinary taxable income for each calendar year, (2) 98.2% of our capital gain net income for the one-year period ending December 31 in that calendar year and (3) any taxable income recognized, but not distributed, in preceding years on which we paid no U.S. federal income tax (the “Excise Tax Avoidance Requirement”). Dividends declared and paid by us in a year will generally differ from taxable income for that year as such dividends may include the distribution of current year taxable income, exclude amounts carried over into the following year, and include the distribution of prior year taxable income carried over into and distributed in the current year. For amounts we carry over into the following year, we will be required to pay the 4% U.S. federal excise tax on the excess of 98% of our annual investment company taxable income and 98.2% of our capital gain net income over our distributions for the year.

In order to qualify as a RIC for U.S. federal income tax purposes, we must, among other things:

•continue to qualify as a BDC under the 1940 Act at all times during each taxable year;

•derive in each taxable year at least 90% of our gross income from dividends, interest, payments with respect to certain securities, loans, gains from the sale of stock or other securities, net income from certain “qualified publicly traded partnerships,” or other income derived with respect to our business of investing in such stock or securities (the “90% Income Test”); and

•diversify our holdings so that at the end of each quarter of the taxable year:

•at least 50% of the value of our assets consists of cash, cash equivalents, U.S. government securities, securities of other RICs, and other securities if such other securities of any one issuer do not represent more than 5% of the value of our assets or more than 10% of the outstanding voting securities of the issuer; and

•no more than 25% of the value of our assets is invested in the securities, other than U.S. government securities or securities of other RICs, (i) of one issuer, (ii) of two or more issuers that are controlled, as determined under applicable Code rules, by us and that are engaged in the same or similar or related trades or businesses or (iii) of certain “qualified publicly traded partnerships” (collectively, the “Diversification Tests”).

In order to comply with the 90% Income Test, we formed the Taxable Subsidiaries as wholly-owned taxable subsidiaries for the primary purpose of permitting us to own equity interests in portfolio companies which are “pass-through” entities for tax purposes. Absent the taxable status of the Taxable Subsidiaries, a portion of the gross income from such portfolio companies would flow directly to us for purposes of the 90% Income Test. To the extent such income did not consist of income derived from securities, such as dividends and interest, it could jeopardize our ability to qualify as a RIC and, therefore, cause us to incur significant U.S. federal income taxes. The Taxable Subsidiaries are consolidated with Main Street for generally accepted accounting principles in the United States of America (“U.S. GAAP”) purposes and are included in our consolidated financial statements, and the portfolio investments held by the Taxable Subsidiaries are included in our consolidated financial statements. The Taxable Subsidiaries are not consolidated with MSCC for income tax purposes and may generate income tax expense, or benefit, as a result of their ownership of the portfolio investments. The income tax expense, or benefit, if any, and any related tax assets and liabilities, are reflected in our consolidated financial statements.

The External Investment Manager is accounted for as a portfolio investment for U.S. GAAP purposes and is an indirect wholly-owned subsidiary of MSCC, owned through a Taxable Subsidiary. The External Investment Manager is owned by a Taxable Subsidiary in order to allow us to comply with the 90% Income Test, since the External Investment Manager’s income would likely not consist of income derived from securities, such as dividends and interest, and as result, if held directly by us, it could jeopardize our ability to qualify as a RIC and, therefore, cause us to incur significant U.S. federal income taxes. As it is wholly-owned by a Taxable Subsidiary, the External Investment Manager is disregarded for tax purposes. The External Investment Manager has also entered into a tax sharing agreement with its Taxable Subsidiary owner. Since the External Investment Manager is accounted for as a portfolio investment of MSCC and is not included as a consolidated subsidiary of MSCC in MSCC’s consolidated financial statements, and as a result of the tax sharing agreement with its Taxable Subsidiary owner, for its stand-alone financial reporting purposes the External Investment Manager is treated as if it is taxed at normal corporate tax rates based on its taxable income and, as a result of its activities, may generate income tax expense or benefit. The income tax expense, or benefit, if any, and the related tax assets and liabilities, of the External Investment Manager are reflected in the External Investment Manager’s separate financial statements.

We may be required to recognize taxable income in circumstances in which we do not receive cash. For example, if we hold debt obligations that are treated under applicable tax rules as having original issue discount (such as debt instruments issued with warrants and debt securities invested in at a discount to par), we must include in income each year a portion of the original issue discount that accrues over the life of the obligation, regardless of whether cash representing such income is received by us in the same taxable year. We may also have to include in income other amounts that we have not yet received in cash such as PIK interest, cumulative dividends or amounts that are received in non-cash compensation such as warrants or stock. Because any original issue discount or other amounts accrued will be included in our investment company taxable income for the year of accrual, we may be required to make a distribution to our stockholders in order to satisfy the Annual Distribution Requirement, even though we will not have received any corresponding cash amount.

Although we do not presently expect to do so, we are authorized to borrow funds and to sell assets in order to satisfy distribution requirements. However, under the 1940 Act, we are not permitted to make distributions to our stockholders in certain circumstances while our debt obligations and other senior securities are outstanding unless certain “asset coverage” tests are met. See Regulation — Regulation as a Business Development Company — Senior Securities. Moreover, our ability to dispose of assets to meet our distribution requirements may be limited by (1) the illiquid nature of our portfolio and/or (2) other requirements relating to our status as a RIC, including the Diversification Tests. If we dispose of assets in order to meet the Annual Distribution Requirement or the Excise Tax Avoidance Requirement, we may make such dispositions at times that, from an investment standpoint, are not advantageous.

We may distribute taxable dividends that are payable in part in our stock. Under certain applicable provisions of the Code and the U.S. Department of the Treasury (“Treasury”) regulations, distributions payable by us in cash or in shares of stock (at the stockholders’ election) would satisfy the Annual Distribution Requirement. The Internal Revenue Service has issued guidance indicating that this rule will apply even where the total amount of cash that may be distributed is limited to no more than 20% of the total distribution. According to this guidance, if too many stockholders elect to receive their distributions in cash, each such stockholder would receive a pro rata share of the total cash to be distributed and would receive the remainder of their distribution in shares of stock. Taxable stockholders receiving such dividends will be required to include the full amount of the dividend (whether received in cash, our stock, or a combination thereof) as (i) ordinary income (including any qualified dividend income that, in the case of a noncorporate stockholder, may be eligible for the same reduced maximum tax rate applicable to long-term capital gains to the extent such distribution is properly reported by us as qualified dividend income and such stockholder satisfies certain minimum holding period requirements with respect to our stock) or (ii) long-term capital gain (to the extent such distribution is properly reported as a capital gain dividend), to the extent of our current and accumulated earnings and profits for U.S. federal income tax purposes. As a result, a U.S. stockholder may be required to pay tax with respect to such dividends in excess of any cash received. If a U.S. stockholder sells the stock it receives in order to pay this tax, the sales proceeds may be less than the amount included in income with respect to the dividend, depending on the market price of our stock at the time of the sale. Furthermore, with respect to non-U.S. stockholders, we may be required to withhold U.S. tax with respect to such dividends, including in respect of all or a portion of such dividend that is payable in stock. In addition, if a significant number of our stockholders determine to sell shares of our stock in order to pay taxes owed on dividends, it may put downward pressure on the trading price of our stock.

Failure to Qualify as a RIC

If we fail to satisfy the 90% Income Test or the Diversification Tests for any taxable year, we may nevertheless continue to qualify as a RIC for such year if certain relief provisions are applicable (which may, among other things, require us to pay certain corporate-level U.S. federal taxes or to dispose of certain assets). We cannot assure you that we will qualify for any such relief should we fail the 90% Income Test or the Diversification Tests.

If we were unable to qualify for treatment as a RIC and the foregoing relief provisions are not applicable, we would be subject to tax on all of our taxable income at regular corporate rates. We would not be able to deduct distributions to stockholders, nor would they be required to be made. If we were subject to tax on all of our taxable income at regular corporate rates, then distributions we make after being subject to such tax would be taxable to our stockholders and, provided certain holding period and other requirements were met, could qualify for treatment as “qualified dividend income” eligible for the maximum 20% rate (plus a 3.8% Medicare surtax, if applicable) applicable to qualified dividends to the extent of our current and accumulated earnings and profits. Subject to certain limitations under the Code, corporate taxpayers would be eligible for a dividends-received deduction on distributions they receive. Distributions in excess of our current and accumulated earnings and profits would be treated first as a return of capital to the extent of the stockholder’s tax basis, and any remaining distributions would be treated as a capital gain. To requalify as a RIC in a subsequent taxable year, we would be required to satisfy the RIC qualification requirements for that year and dispose of any earnings and profits from any year in which we failed to qualify as a RIC. Subject to a limited exception applicable to RICs that qualified as such under Subchapter M of the Code for at least one year prior to disqualification and that requalify as a RIC no later than the second year following the nonqualifying year, we could be subject to tax on any unrealized net built-in gains in the assets held by us during the period in which we failed to qualify as a RIC that are recognized within the subsequent five years, unless we made a special election to pay corporate-level U.S. federal income tax on such built-in gain at the time of our requalification as a RIC.