Formation and Business Purpose	3 Months Ended
Mar. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Formation and Business Purpose	Formation and Business Purpose New Mountain Private Credit Fund (the "Company" or the "Successor") is a Maryland statutory trust formed on August 19, 2024. The Company is a closed-end, non-diversified management investment company that has elected to be regulated as a business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). The Company intends to elect to be treated for United States federal income tax purposes, and to qualify thereafter, as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). The Company commenced operations on December 17, 2024. On December 17, 2024, the Company completed its previously announced acquisition of New Mountain Guardian III BDC, L.L.C., a Delaware limited liability company (“GIII” or the "Predecessor"). Pursuant to that certain Agreement and Plan of Merger (the “Merger Agreement”) by and among the Company, GIII, and, solely for the limited purposes set forth therein, the Investment Adviser (as defined below), dated as of October 11, 2024, GIII merged with and into the Company, with the Company continuing as the surviving company (the "Merger"). the Company's consolidated financial statements are presented as Predecessor for the periods prior to the Merger on December 17, 2024, and Successor for subsequent periods. In accordance with the terms of the Merger Agreement, at the effective time of the Merger, each GIII unitholder was given the opportunity to transfer all or a portion of their units of GIII limited liability company interests (the "Units") to the Company prior to the closing in exchange for the Company's common shares of beneficial interest ("Shares"). As a result of the Merger, the Company issued an aggregate of 24,216,852 Shares to former GIII unitholders. The Merger is accounted for as a common control transaction between GIII and the Company. In accordance with the common control method of accounting, as detailed in Accounting Standards Codification Topic 805-50, Business Combinations - Related Issues, there is no change in basis of the assets and liabilities. Accordingly, the ongoing financial statements of the Company are presented as a continuation of those of GIII, such that the assets and liabilities of GIII were contributed to the Company at their current carrying values, and the equity of the Company was adjusted to reflect the equity of GIII immediately prior to the Merger. The Company is the accounting survivor of the Merger. The Merger was considered a tax-free reorganization and the historical cost basis of the acquired GIII investments are carried forward for tax purposes. New Mountain Finance Advisers, L.L.C. (the "Investment Adviser"), formerly known as New Mountain Finance Advisers BDC, L.L.C., is a wholly-owned subsidiary of New Mountain Capital Group, L.P. (together with New Mountain Capital, L.L.C. and its affiliates, "New Mountain Capital"), whose ultimate owners include Steven B. Klinsky, other current and former New Mountain Capital professionals and related vehicles and a minority investor. New Mountain Capital is a global investment firm with approximately $55 billion of assets under management and a track record of investing in the middle market. New Mountain Capital focuses on investing in defensive growth companies across its private equity, credit and net lease investment strategies. The Investment Adviser manages the Company's day-to-day operations and provides it with investment advisory and management services. The Investment Adviser also manages other funds that may have investment mandates that are similar, in whole or in part, to the Company's. New Mountain Finance Administration, L.L.C. (the "Administrator"), a wholly-owned subsidiary of New Mountain Capital, provides the administrative services necessary to conduct the Company's day-to-day operations. The Administrator has hired a third-party sub-administrator to assist with the provision of administrative services. New Mountain Private Credit Fund SPV I, L.L.C. ("NEWCRED SPV"), formerly known as New Mountain Guardian III SPV L.L.C ("GIII SPV"), is a wholly-owned direct subsidiary of the Company, whose assets are used to secure NEWCRED SPV's credit facility. New Mountain Private Credit Fund OEC, Inc. ("NEWCRED OEC"), formerly known as New Mountain Guardian III OEC, Inc ("GIII OEC"), is a wholly-owned direct subsidiary of the Company, which is treated as a corporation for U.S. federal income tax purposes and is intended to facilitate our compliance with the requirements to be treated as a RIC under the Code by holding equity or equity like investments in one of the Company's portfolio companies organized as a limited liability company; the Company consolidates this corporation for accounting purposes, but the corporation is not consolidated for U.S. federal income tax purposes and may incur U.S. federal income tax expense as a result of its ownership of the portfolio company. The Company focuses on providing direct lending solutions to U.S. upper middle market companies backed by top private equity sponsors. The Company's investment objective is to generate current income and capital appreciation through the sourcing and origination of senior secured loans and select junior capital positions, to growing businesses in defensive industries that offer attractive risk-adjusted returns. The Company's differentiated investment approach leverages the deep sector knowledge and operating resources of New Mountain Capital. The Company primarily invests in senior secured debt of U.S. sponsor-backed, middle market companies. The Company defines middle market companies as those with annual earnings before interest, taxes, depreciation, and amortization ("EBITDA") between $10,000 and $200,000. The Company focuses on defensive growth businesses that generally exhibit the following characteristics: (i) acyclicality, (ii) sustainable secular growth drivers, (iii) niche market dominance and high barriers to competitive entry, (iv) recurring revenue and strong free cash flow, (v) flexible cost structures and (vi) seasoned management teams. Senior secured loans may include traditional first lien loans or unitranche loans. The Company invests a significant portion of its portfolio in unitranche loans, which are loans that combine both senior and subordinated debt, generally in a first-lien position. Because unitranche loans combine characteristics of senior and subordinated debt, they have risks similar to the risks associated with secured debt and subordinated debt. Certain unitranche loan investments may include “last-out” positions, which generally heighten the risk of loss. In some cases, the Company’s investments may also include equity interests. As of March 31, 2025, the Company's top five industry concentrations were software, healthcare, business services, consumer services and financial services.

New Mountain Private Credit Fund (the "Company" or the "Successor") is a Maryland statutory trust formed on August 19, 2024. The Company is a closed-end, non-diversified management investment company that has elected to be regulated as a business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). The Company intends to elect to be treated for United States federal income tax purposes, and to qualify thereafter, as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). The Company commenced operations on December 17, 2024.

On December 17, 2024, the Company completed its previously announced acquisition of New Mountain Guardian III BDC, L.L.C., a Delaware limited liability company (“GIII” or the "Predecessor"). Pursuant to that certain Agreement and Plan of Merger (the “Merger Agreement”) by and among the Company, GIII, and, solely for the limited purposes set forth therein, the Investment Adviser (as defined below), dated as of October 11, 2024, GIII merged with and into the Company, with the Company continuing as the surviving company (the "Merger"). the Company's consolidated financial statements are presented as Predecessor for the periods prior to the Merger on December 17, 2024, and Successor for subsequent periods. In accordance with the terms of the Merger Agreement, at the effective time of the Merger, each GIII unitholder was given the opportunity to transfer all or a portion of their units of GIII limited liability company interests (the "Units") to the Company prior to the closing in exchange for the Company's common shares of beneficial interest ("Shares"). As a result of the Merger, the Company issued an aggregate of 24,216,852 Shares to former GIII unitholders.

The Merger is accounted for as a common control transaction between GIII and the Company. In accordance with the common control method of accounting, as detailed in Accounting Standards Codification Topic 805-50, Business Combinations - Related Issues, there is no change in basis of the assets and liabilities. Accordingly, the ongoing financial statements of the Company are presented as a continuation of those of GIII, such that the assets and liabilities of GIII were contributed to the Company at their current carrying values, and the equity of the Company was adjusted to reflect the equity of GIII immediately prior to the Merger. The Company is the accounting survivor of the Merger. The Merger was considered a tax-free reorganization and the historical cost basis of the acquired GIII investments are carried forward for tax purposes.

New Mountain Finance Advisers, L.L.C. (the "Investment Adviser"), formerly known as New Mountain Finance Advisers BDC, L.L.C., is a wholly-owned subsidiary of New Mountain Capital Group, L.P. (together with New Mountain Capital, L.L.C. and its affiliates, "New Mountain Capital"), whose ultimate owners include Steven B. Klinsky, other current and former New Mountain Capital professionals and related vehicles and a minority investor. New Mountain Capital is a global investment firm with approximately $55 billion of assets under management and a track record of investing in the middle market. New Mountain Capital focuses on investing in defensive growth companies across its private equity, credit and net lease investment strategies. The Investment Adviser manages the Company's day-to-day operations and provides it with investment advisory and management services. The Investment Adviser also manages other funds that may have investment mandates that are similar, in whole or in part, to the Company's. New Mountain Finance Administration, L.L.C. (the "Administrator"), a wholly-owned subsidiary of New Mountain Capital, provides the administrative services necessary to conduct the Company's day-to-day operations. The Administrator has hired a third-party sub-administrator to assist with the provision of administrative services.

New Mountain Private Credit Fund SPV I, L.L.C. ("NEWCRED SPV"), formerly known as New Mountain Guardian III SPV L.L.C ("GIII SPV"), is a wholly-owned direct subsidiary of the Company, whose assets are used to secure NEWCRED SPV's credit facility. New Mountain Private Credit Fund OEC, Inc. ("NEWCRED OEC"), formerly known as New Mountain Guardian III OEC, Inc ("GIII OEC"), is a wholly-owned direct subsidiary of the Company, which is treated as a corporation for U.S. federal income tax purposes and is intended to facilitate our compliance with the requirements to be treated as a RIC under the Code by holding equity or equity like investments in one of the Company's portfolio companies organized as a limited liability company; the Company consolidates this corporation for accounting purposes, but the corporation is not consolidated for U.S. federal income tax purposes and may incur U.S. federal income tax expense as a result of its ownership of the portfolio company.

The Company focuses on providing direct lending solutions to U.S. upper middle market companies backed by top private equity sponsors. The Company's investment objective is to generate current income and capital appreciation through the sourcing and origination of senior secured loans and select junior capital positions, to growing businesses in defensive industries that offer attractive risk-adjusted returns. The Company's differentiated investment approach leverages the deep sector knowledge and operating resources of New Mountain Capital.

The Company primarily invests in senior secured debt of U.S. sponsor-backed, middle market companies. The Company defines middle market companies as those with annual earnings before interest, taxes, depreciation, and amortization ("EBITDA") between $10,000 and $200,000. The Company focuses on defensive growth businesses that generally exhibit the following characteristics: (i) acyclicality, (ii) sustainable secular growth drivers, (iii) niche market dominance and high barriers to competitive entry, (iv) recurring revenue and strong free cash flow, (v) flexible cost structures and (vi) seasoned management teams.

Senior secured loans may include traditional first lien loans or unitranche loans. The Company invests a significant portion of its portfolio in unitranche loans, which are loans that combine both senior and subordinated debt, generally in a first-lien position. Because unitranche loans combine characteristics of senior and subordinated debt, they have risks similar to the risks associated with secured debt and subordinated debt. Certain unitranche loan investments may include “last-out” positions, which generally heighten the risk of loss. In some cases, the Company’s investments may also include equity interests.