Firm Description Founded as predecessor entity Keystone Capital Inc. in 1994, Keystone Capital Management, LP is a Chicago-based private equity firm that invests in lower middle market companies with a primary focus on partnering with privately held businesses with between approximately $5 million and $20 million in EBITDA and operating in markets that Keystone believes offer compelling organic and inorganic growth and diversification potential. Keystone Capital Management, LP (the registrant, “Keystone”) was formed in 2020. Keystone serves as the investment adviser for the following private funds: Keystone Capital Fund II, LP and Keystone Capital Fund II-A, LP (together, “Fund II”); and Keystone Capital Fund III, LP and Keystone Capital Fund III-A, LP (together, “Fund III” and collectively with Fund II, the “Funds”). Keystone also acts as the investment manager to several pre-fund investments (the “Pre- Fund Investments”) which are comprised primarily of proprietary capital vehicles and are not clients of Keystone (and not generally included in this Brochure unless specifically noted). In addition, in certain circumstances, as more fully described in Item 7 below, the Firm permits certain limited partners and third parties to co-invest alongside a Fund directly in a portfolio company. Such direct co-investments are not managed by Keystone and are not considered Funds or clients of Keystone. Each Fund is affiliated with a general partner (“General Partner”) with authority to make investment decisions on behalf of the Funds. The General Partners are deemed registered under the Investment Advisers Act of 1940, as amended, and the rules and regulations promulgated thereunder (“Advisers Act”), pursuant to Keystone’s registration in accordance with SEC guidance. The applicable General Partner of each Fund retains investment discretion and limited partners in the Funds do not participate in the control or management of the Funds. While the General Partners maintain ultimate authority over the Funds, Keystone has been designated the role of investment adviser. For more information about the Funds and General Partners, please see Keystone’s Form ADV Part 1, Schedule D, Section 7.A. and Section 7.B.(1) Keystone provides investment advisory services as a private equity fund manager to its Funds. The Funds invest through privately negotiated transactions in operating companies, generally referred to as “portfolio companies”, in the target sectors (as described in more detail in Item 8, below). Each portfolio company has its own independent management team responsible for managing its day-to- day operations, although (i) members of Keystone or representatives appointed by the Firm are expected to serve on the boards of, or otherwise act to influence control of the management of, such portfolio companies and will therefore have a significant impact on the long-term direction of the company, including the selection of management team members and (ii) in some cases, Keystone will more directly influence the day-to-day management of a portfolio company by recruiting and installing certain individuals in various leadership roles, such as chief executive officer, chief operating officer, chief financial officer or in other roles. Keystone’s investment advisory services to the Funds consist of identifying and evaluating investment opportunities, negotiating the terms of investments, managing

and monitoring investments and achieving dispositions of such investments. Investments are made predominantly in non-public companies, although investments in public companies are permitted in certain instances. Keystone’s investment advice and authority for each Fund is tailored to the investment objectives of that Fund; Keystone does not tailor its advisory services to the individual needs of limited partners in its Funds. The Fund investment objectives are described in and governed by, as applicable, the private placement memorandum, limited partnership agreement, subscription agreements, investment advisory agreements, side letter agreements and other governing documents of the relevant Fund (collectively, “Governing Documents”) and limited partners determine the suitability of an investment in a Fund based on, among other things, the Governing Documents. The Firm does not seek or require limited partner approval regarding each investment decision. Fund limited partners generally cannot impose restrictions on investing in certain securities or types of securities, other than through side letter agreements. Limited partners in the Funds participate in the overall investment program for the applicable Fund and generally cannot be excused from a particular investment except in certain circumstances pursuant to the terms of the applicable Governing Documents. In accordance with industry common practice, Keystone has entered into side letter or other similar agreements with certain limited partners including those who make substantial commitments of capital or were early-stage limited partners in the Funds, or for other reasons in the sole discretion of Keystone, in each case that have the effect of establishing rights under, or altering or supplementing, a Fund’s Governing Documents. Examples of side letter and other similar agreements entered into include provisions whereby limited partners have expressed an interest in participating in co-investment opportunities, advisory board representation, certain fee arrangements, notification provisions, reporting requirements and “most favored nations” provisions, among others. These rights, benefits or privileges are not always made available to all limited partners, consistent with the Governing Documents and general market practice. Commencing in March 2025, Keystone will make required disclosure of certain side letters to all limited partners (and in certain cases, to prospective limited partners) in accordance with the new Private Fund Rule. Side letters are negotiated at the time of the relevant limited partner’s capital commitment, and once invested in a Fund, limited partners generally cannot impose additional investment guidelines or restrictions on such Fund. There can be no assurance that the side letter rights granted to one or more limited partners will not in certain cases disadvantage other limited partners. Keystone does not participate in wrap fee programs. Principal Owners Keystone is ultimately owned by Kent Dauten and Scott Gwilliam. For more information about the owners and executive officers of Keystone, please see Keystone’s Form ADV Part 1, Schedules A and B. Regulatory Assets Under Management As of the February 12, 2024, Keystone managed approximately $1,163,588,749 in regulatory assets under management, all managed on a discretionary basis.