New Mountain Guardian IV BDC L.L.C. 10-Q 15 May 23 2023 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2023	May 15, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	000-56437
Entity Registrant Name	New Mountain Guardian IV BDC, L.L.C.
Entity Address, Address Line One	1633 Broadway, 48th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10019
City Area Code	212
Local Phone Number	720-0300
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	88-1377220
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		8,508,331
Entity Central Index Key	0001925531
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1

Consolidated Statements of Asse

Consolidated Statements of Assets, Liabilities and Members' Capital - USD ($) $ in Thousands	Mar. 31, 2023		Dec. 31, 2022
Assets
Non-controlled/non-affiliated investments at fair value (cost of $190,895 and $123,436 respectively)	$ 191,960	[1]	$ 123,211	[2]
Cash and cash equivalents	2,879		5,793
Interest and dividend receivable	1,230		826
Other assets	1,301		130
Total assets	197,370		129,960
Borrowings
Deferred financing costs (net of accumulated amortization of $75 and $11 respectively)	(1,600)		(24)
Net borrowings	101,800		53,676
Payable for unsettled securities purchased	5,995		0
Distribution payable	2,594		1,336
Interest payable	1,304		363
Incentive fee payable	369		208
Payable to affiliate	209		167
Management fee payable	186		111
Other liabilities	782		582
Total liabilities	113,239		56,443
Commitments and contingencies (See Note 8)
Members' Capital
Common units, 8,508,331 and 7,525,831 units issued and outstanding, respectively	84,509		74,684
Accumulated overdistributed earnings	(378)		(1,167)
Total members' capital	84,131		73,517
Total liabilities and members' capital	$ 197,370		$ 129,960
Members' capital per unit (in dollars per share)	$ 9.89		$ 9.77
UBS Credit Facility
Borrowings
Credit Facility/ Subscription Line	$ 58,400		$ 0
BMO Subscription Line
Borrowings
Credit Facility/ Subscription Line	$ 45,000		$ 53,700
[1]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.[2]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.

Consolidated Statements of As_2

Consolidated Statements of Assets, Liabilities and Members' Capital (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023		Dec. 31, 2022
Statement of Financial Position [Abstract]
Investments, cost	$ 190,895	[1]	$ 123,436	[2]
Deferred financing costs, accumulated amortization	$ 75		$ 11
Common units, units issued (in shares)	8,508,331		7,525,831
Common units, units outstanding (in shares)	8,508,331		7,525,831
[1]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.[2]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.

Consolidated Statement of Opera

Consolidated Statement of Operations $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares
Investment income
Interest income	$ 4,445
Dividend income	25
Fee income	799
Total investment income	5,269
Expenses
Interest and other financing expenses	1,936
Management fee	372
Incentive fee	369
Administrative expenses	247
Organizational and offering expenses	201
Professional fees	187
Other general and administrative expenses	50
Total expenses	3,362
Less: management fees waived (See Note 5)	(186)
Net expenses	3,176
Net investment income	2,093
Net change in unrealized appreciation of investments	1,290
Net realized and unrealized gains	1,290
Net increase in members' capital resulting from operations	$ 3,383
Earnings per unit - basic (in dollars per share) | $ / shares	$ 0.43
Earnings per unit - diluted (in dollars per share) | $ / shares	$ 0.43
Average weighted units outstanding for the period - basic (in shares) | shares	7,776,914
Average weighted units outstanding for the period - diluted (in shares) | shares	7,776,914

Consolidated Statement of Chang

Consolidated Statement of Changes in Members' Capital $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) shares
Increase (Decrease) in members' capital resulting from operations:
Net investment income	$ 2,093
Net change in unrealized appreciation of investments	1,290
Net increase in members' capital resulting from operations	3,383
Capital transactions
Contributions	9,825
Distributions declared to unitholders from net investment income	(2,594)
Total net increase in members' capital resulting from capital transactions	7,231
Net increase in members' capital	10,614
Members' capital at the beginning of the period	73,517
Members' capital at the end of the period	$ 84,131
Capital unit activity
Units issued (in shares) | shares	982,500

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Cash flows from operating activities
Net increase in members' capital resulting from operations	$ 3,383
Adjustments to reconcile net decrease in members' capital resulting from operations to net cash used in operating activities:
Net change in unrealized appreciation of investments	(1,290)
Amortization of purchase discount	(237)
Amortization of deferred financing costs	64
Amortization of deferred offering costs	46
Non-cash investment income	(147)
(Increase) decrease in operating assets:
Cash received for purchase of undrawn portion of revolving credit or delayed draw facilities	52
Interest and dividend receivable	(404)
Other assets	(1,217)
Increase (decrease) in operating liabilities:
Payable for unsettled securities purchased	5,995
Interest payable	941
Incentive fee payable	161
Management fee payable	75
Payable to affiliates	42
Other liabilities	228
Net cash flows used in operating activities	(59,435)
Cash flows from financing activities
Distributions	(1,336)
Net proceeds from issuance of common units	9,825
Repayment of Subscription Line	(34,600)
Placement fees paid	(28)
Deferred financing costs paid	(1,640)
Net cash flows provided by financing activities	56,521
Net decrease in cash and cash equivalents	(2,914)
Cash and cash equivalents at the beginning of the period	5,793
Cash and cash equivalents at the end of the period	2,879
Supplemental disclosure of cash flow information
Cash interest paid	2,020
Non-cash financing activities:
Distribution payable	2,594
Investments including delayed draw facilities
(Increase) decrease in operating assets:
Cash paid for purchase of investments	(67,350)
Investments excluding drawn revolvers
(Increase) decrease in operating assets:
Proceeds from sales and paydowns/ repayments of investments	273
Drawn revolvers
(Increase) decrease in operating assets:
Cash paid for purchase of investments	(666)
Proceeds from sales and paydowns/ repayments of investments	616
BMO Subscription Line
Cash flows from financing activities
Proceeds from Subscription Line/ Credit Facility	25,900
UBS Credit Facility
Cash flows from financing activities
Proceeds from Subscription Line/ Credit Facility	$ 58,400

Consolidated Schedule of Invest

Consolidated Schedule of Investments - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2023		Dec. 31, 2022
Cost		$ 190,895	[1]	$ 123,436	[2]
Fair Value		$ 191,960	[1]	$ 123,211	[2]
Percent of Net Assets		228.17%		94.81%
Percent of Total Investments at Fair Value		100%		100%
Software
Cost		$ 104,533		$ 60,274
Fair Value		$ 105,443		$ 60,506
Software | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		54.93%		49.11%
Business Services
Cost		$ 46,122		$ 29,285
Fair Value		$ 45,926		$ 29,035
Business Services | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		23.91%		23.57%
Healthcare
Cost		$ 16,127		$ 14,727
Fair Value		$ 16,157		$ 14,506
Healthcare | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		8.42%		11.77%
Consumer Services
Cost		$ 10,398		$ 6,343
Fair Value		$ 10,208		$ 6,138
Consumer Services | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		5.32%		4.98%
Education
Cost		$ 6,273		$ 5,442
Fair Value		$ 6,886		$ 5,858
Education | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		3.59%		4.75%
Distribution & Logistics
Cost		$ 5,540		$ 5,459
Fair Value		$ 5,410		$ 5,321
Distribution & Logistics | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		2.82%		4.32%
Financial Services
Cost		$ 1,902		$ 1,906
Fair Value		$ 1,930		$ 1,847
Financial Services | Investments at fair value | Industry Type
Percent of Total Investments at Fair Value		1.01%		1.50%
Funded Debt Investments
Principal Amount, Par Value		$ 198,173		$ 128,592
Cost		190,180		122,720
Fair Value		$ 191,629		$ 122,989
Percent of Net Assets		227.77%		94.64%
Funded Debt Investments | United States
Principal Amount, Par Value		$ 190,344		$ 120,763
Cost		182,440		114,984
Fair Value		$ 183,943		$ 115,307
Percent of Net Assets		218.64%		88.73%
Funded Debt Investments | United Kingdom
Principal Amount, Par Value		$ 4,375		$ 4,375
Cost		4,336		4,334
Fair Value		$ 4,284		$ 4,280
Percent of Net Assets		5.09%		3.29%
Funded Debt Investments | Australia
Principal Amount, Par Value		$ 3,454		$ 3,454
Cost		3,404		3,402
Fair Value		$ 3,402		$ 3,402
Percent of Net Assets		4.04%		2.62%
Equity
Cost		$ 828		$ 779
Fair Value		$ 827		$ 763
Percent of Net Assets		0.98%		0.59%
Equity | United States
Cost		$ 828		$ 779
Fair Value		$ 827		$ 763
Percent of Net Assets		0.98%		0.59%
Funded Investments
Cost		$ 191,008		$ 123,499
Fair Value		$ 192,456		$ 123,752
Percent of Net Assets		228.75%		95.23%
Unfunded Debt Investments
Principal Amount, Par Value		$ 39,487		$ 36,202
Cost		(113)		(63)
Fair Value		$ (496)		$ (541)
Percent of Net Assets		(0.58%)		(0.42%)
Unfunded Debt Investments | United States
Principal Amount, Par Value		$ 39,167		$ 35,882
Cost		(108)		(58)
Fair Value		$ (491)		$ (536)
Percent of Net Assets		(0.58%)		(0.42%)
Unfunded Debt Investments | Australia
Principal Amount, Par Value		$ 320		$ 320
Cost		(5)		(5)
Fair Value		$ (5)		$ (5)
Percent of Net Assets		(0.01%)		(0.00%)
First lien
Cost		$ 165,291		$ 100,860
Fair Value		$ 164,905		$ 99,866
First lien | Investments at fair value | Investment Type
Percent of Total Investments at Fair Value		85.91%		81.05%
Second lien
Cost		$ 13,902		$ 10,991
Fair Value		$ 15,299		$ 11,852
Second lien | Investments at fair value | Investment Type
Percent of Total Investments at Fair Value		7.97%		9.62%
Subordinated
Cost		$ 10,874		$ 10,806
Fair Value		$ 10,929		$ 10,730
Subordinated | Investments at fair value | Investment Type
Percent of Total Investments at Fair Value		5.69%		8.71%
Equity and other
Cost		$ 828		$ 779
Fair Value		$ 827		$ 763
Equity and other | Investments at fair value | Investment Type
Percent of Total Investments at Fair Value		0.43%		0.62%
Floating rates | Investments at fair value | Interest Rate Type
Percent of Total Investments at Fair Value		95.46%		93.17%
Fixed rates | Investments at fair value | Interest Rate Type
Percent of Total Investments at Fair Value		4.54%		6.83%
Nielsen Consumer Inc. | Funded Debt Investments
Principal Amount, Par Value		$ 10,000
Cost		8,901
Fair Value	[3]	$ 8,825
Percent of Net Assets		10.49%
PPV Intermediate Holdings LLC | Funded Debt Investments
Principal Amount, Par Value		$ 6,304		$ 5,915
Cost		6,246		5,859
Fair Value		$ 6,168		$ 5,800
Percent of Net Assets		7.33%		4.46%
PPV Intermediate Holdings LLC | Unfunded Debt Investments
Principal Amount, Par Value		$ 696		$ 1,086
Cost		(4)		(2)
Fair Value		$ (15)		$ (21)
Percent of Net Assets		(0.02%)		(0.02%)
Infogain Corporation | Funded Debt Investments
Principal Amount, Par Value		$ 5,893		$ 5,900
Cost		5,832		5,836
Fair Value		$ 5,762		$ 5,775
Percent of Net Assets		6.85%		4.44%
Radwell Parent, LLC | Funded Debt Investments
Principal Amount, Par Value		$ 5,588
Cost		5,509
Fair Value		$ 5,505
Percent of Net Assets		6.54%
IMO Investor Holdings, Inc. | Funded Debt Investments
Principal Amount, Par Value		$ 4,795		$ 4,697
Cost		4,753		4,655
Fair Value		$ 4,700		$ 4,650
Percent of Net Assets		5.59%		3.58%
IMO Investor Holdings, Inc. | Unfunded Debt Investments
Principal Amount, Par Value		$ 1,430		$ 1,540
Cost		(3)		(5)
Fair Value		$ (28)		$ (16)
Percent of Net Assets		(0.04%)		(0.01%)
Foreside Financial Group | Funded Debt Investments
Principal Amount, Par Value		$ 3,620
Cost		3,589
Fair Value		$ 3,584
Percent of Net Assets		4.26%
Foreside Financial Group | Unfunded Debt Investments
Principal Amount, Par Value		$ 728		$ 743
Cost		(2)		(2)
Fair Value		$ (8)		$ (7)
Percent of Net Assets		(0.01%)		(0.01%)
Trident Bidco Limited | Funded Debt Investments
Principal Amount, Par Value		$ 4,375		$ 4,375
Cost		4,336		4,334
Fair Value		$ 4,284	[3]	$ 4,280	[4]
Percent of Net Assets		5.09%		3.29%
iCIMS, Inc. | Unfunded Debt Investments
Principal Amount, Par Value		$ 3,361		$ 3,460
Cost		(7)		(8)
Fair Value		$ (5)		$ (8)
Percent of Net Assets		(0.01%)		(0.01%)
Kaseya Inc | Unfunded Debt Investments
Principal Amount, Par Value		$ 952	[5]	$ 952	[6]
Cost		(3)	[5]	(3)	[6]
Fair Value		$ (8)	[5]	$ (14)	[6]
Percent of Net Assets		(0.01%)		(0.01%)
Affinipay Midco, LLC | Unfunded Debt Investments
Principal Amount, Par Value		$ 867		$ 866
Cost		(2)		(2)
Fair Value		$ (9)		$ (9)
Percent of Net Assets		(0.01%)		(0.01%)
Groundworks, LLC | Unfunded Debt Investments
Principal Amount, Par Value		$ 712
Cost		(3)
Fair Value		$ (11)
Percent of Net Assets		(0.01%)
DOCS, MSO, LLC | Unfunded Debt Investments
Principal Amount, Par Value		$ 1,340		$ 1,340
Cost		0		0
Fair Value		$ (11)		$ (37)
Percent of Net Assets		(0.01%)		(0.03%)
Coupa Holdings, LLC | Unfunded Debt Investments
Principal Amount, Par Value		$ 3,103
Cost		(17)
Fair Value		$ (27)
Percent of Net Assets		(0.03%)
CoreTrust Purchasing Group LLC | Unfunded Debt Investments
Principal Amount, Par Value		$ 2,960		$ 2,960
Cost		(21)		(20)
Fair Value		$ (44)		$ (44)
Percent of Net Assets		(0.05%)		(0.03%)
Investment, Identifier [Axis]: Affinipay Midco, LLC, First lien
Spread		5.75%	[7],[8],[9]	5.75%	[10],[11]
Interest Rate		10.64%	[7],[8],[9]	10.64%	[10],[11]
Principal Amount, Par Value		$ 4,169	[7],[9]	$ 4,180	[11]
Cost		4,132	[7],[9]	4,141	[11]
Fair Value		$ 4,128	[7],[9]	$ 4,138	[11]
Percent of Net Assets		4.91%		3.19%
Investment, Identifier [Axis]: Affinipay Midco, LLC, First lien - Undrawn 1
Principal Amount, Par Value		$ 280	[7],[12]	$ 279	[11],[13]
Cost		(2)	[7],[12]	(2)	[11],[13]
Fair Value		(3)	[7],[12]	(3)	[11],[13]
Investment, Identifier [Axis]: Affinipay Midco, LLC, First lien - Undrawn 2
Principal Amount, Par Value		587	[7],[12]	587	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (6)	[7],[12]	$ (6)	[11],[13]
Investment, Identifier [Axis]: Anaplan, Inc., First lien
Spread		6.50%	[7],[8],[9]	6.50%	[10],[11]
Interest Rate		11.31%	[7],[8],[9]	10.82%	[10],[11]
Principal Amount, Par Value		$ 3,000	[7],[9]	$ 3,000	[11]
Cost		2,973	[7],[9]	2,972	[11]
Fair Value		$ 2,970	[7],[9]	$ 2,970	[11]
Percent of Net Assets		3.53%		2.29%
Investment, Identifier [Axis]: Atlas AU Bidco Pty Ltd, First lien
Spread		7.25%	[7],[8],[9]	7.25%	[10]
Interest Rate		11.98%	[7],[8],[9]	11.48%	[10]
Principal Amount, Par Value		$ 3,454	[7],[9]	$ 3,454
Cost		3,404	[7],[9]	3,402
Fair Value		$ 3,402	[3],[7],[9]	$ 3,402	[4]
Percent of Net Assets		4.04%		2.62%
Investment, Identifier [Axis]: Atlas AU Bidco Pty Ltd, First lien - Undrawn
Principal Amount, Par Value		$ 320	[7],[12]	$ 320	[13]
Cost		(5)	[7],[12]	(5)	[13]
Fair Value		$ (5)	[3],[7],[12]	$ (5)	[4],[13]
Percent of Net Assets		(0.01%)		(0.00%)
Investment, Identifier [Axis]: Avalara, Inc., First lien
Spread		7.25%	[7],[8],[9]	7.25%	[10],[11]
Interest Rate		12.15%	[7],[8],[9]	11.83%	[10],[11]
Principal Amount, Par Value		$ 7,955	[7],[9]	$ 7,954	[11]
Cost		7,861	[7],[9]	7,857	[11]
Fair Value		$ 7,945	[7],[9]	$ 7,886	[11]
Percent of Net Assets		9.44%		6.07%
Investment, Identifier [Axis]: Avalara, Inc., First lien - Undrawn
Principal Amount, Par Value		$ 795	[7],[12]	$ 795	[11],[13]
Cost		(9)	[7],[12]	(10)	[11],[13]
Fair Value		$ (1)	[7],[12]	$ (7)	[11],[13]
Percent of Net Assets		(0.00%)		(0.01%)
Investment, Identifier [Axis]: Barracuda Parent, LLC, First lien
Spread		4.50%	[8],[9]	4.50%	[10]
Interest Rate		9.18%	[8],[9]	8.59%	[10]
Principal Amount, Par Value		$ 2,993	[9]	$ 3,000
Cost		2,951	[9]	2,957
Fair Value		$ 2,879	[9]	$ 2,893
Percent of Net Assets		3.42%		2.23%
Investment, Identifier [Axis]: Cloudera, Inc., Second lien
Spread		6%	[8],[9]	6%	[10]
Interest Rate		10.91%	[8],[9]	10.38%	[10]
Principal Amount, Par Value		$ 7,900	[9]	$ 5,500
Cost		6,563	[9]	4,498
Fair Value		$ 7,031	[9]	$ 4,613
Percent of Net Assets		8.36%		3.55%
Investment, Identifier [Axis]: CoreTrust Purchasing Group LLC, First lien
Spread		6.75%	[7],[8],[9]	6.75%	[10],[11]
Interest Rate		11.56%	[7],[8],[9]	10.84%	[10],[11]
Principal Amount, Par Value		$ 10,139	[7],[9]	$ 10,164	[11]
Cost		9,997	[7],[9]	10,017	[11]
Fair Value		$ 9,987	[7],[9]	$ 10,012	[11]
Percent of Net Assets		11.87%		7.70%
Investment, Identifier [Axis]: CoreTrust Purchasing Group LLC, First lien - Undrawn 1
Principal Amount, Par Value		$ 1,480	[7],[12]	$ 1,480	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		(22)	[7],[12]	(22)	[11],[13]
Investment, Identifier [Axis]: CoreTrust Purchasing Group LLC, First lien - Undrawn 2
Principal Amount, Par Value		1,480	[7],[12]	1,480	[11],[13]
Cost		(21)	[7],[12]	(20)	[11],[13]
Fair Value		$ (22)	[7],[12]	$ (22)	[11],[13]
Investment, Identifier [Axis]: Coupa Holdings, LLC, First lien
Spread	[7],[8],[9]	7.50%
Interest Rate	[7],[8],[9]	12.29%
Principal Amount, Par Value	[7],[9]	$ 19,683
Cost	[7],[9]	19,441
Fair Value	[7],[9]	$ 19,510
Percent of Net Assets		23.19%
Investment, Identifier [Axis]: Coupa Holdings, LLC, First lien - Undrawn 1
Principal Amount, Par Value	[7],[12]	$ 1,346
Cost	[7],[12]	(17)
Fair Value	[7],[12]	(12)
Investment, Identifier [Axis]: Coupa Holdings, LLC, First lien - Undrawn 2
Principal Amount, Par Value	[7],[12]	1,757
Cost	[7],[12]	0
Fair Value	[7],[12]	$ (15)
Investment, Identifier [Axis]: DOCS, MSO, LLC, First lien
Spread		5.75%	[7],[8],[9]	5.75%	[10],[11]
Interest Rate		10.54%	[7],[8],[9]	10.54%	[10],[11]
Principal Amount, Par Value		$ 3,012	[7],[9]	$ 3,027	[11]
Cost		3,012	[7],[9]	3,027	[11]
Fair Value		$ 2,985	[7],[9]	$ 2,944	[11]
Percent of Net Assets		3.55%		2.27%
Investment, Identifier [Axis]: DOCS, MSO, LLC, First lien - Undrawn 1
Principal Amount, Par Value		$ 282	[7],[12]	$ 282	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		(2)	[7],[12]	(8)	[11],[13]
Investment, Identifier [Axis]: DOCS, MSO, LLC, First lien - Undrawn 2
Principal Amount, Par Value		1,058	[7],[12]	1,058	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (9)	[7],[12]	$ (29)	[11],[13]
Investment, Identifier [Axis]: DS Admiral Bidco, LLC, First lien
Spread		7%	[7],[8],[9]	7%	[10]
Interest Rate		11.90%	[7],[8],[9]	11.51%	[10]
Principal Amount, Par Value		$ 7,528	[7],[9]	$ 7,547
Cost		7,420	[7],[9]	7,435
Fair Value		$ 7,415	[7],[9]	$ 7,434
Percent of Net Assets		8.81%		5.72%
Investment, Identifier [Axis]: Disco Parent, Inc., First lien
Spread	[8],[9]	7.50%
Interest Rate	[8],[9]	12.39%
Principal Amount, Par Value	[9]	$ 8,900
Cost	[9]	8,789
Fair Value	[9]	$ 8,789
Percent of Net Assets		10.45%
Investment, Identifier [Axis]: Disco Parent, Inc., First lien - Undrawn
Principal Amount, Par Value	[12]	$ 890
Cost	[12]	(11)
Fair Value	[12]	$ (11)
Percent of Net Assets		(0.01%)
Investment, Identifier [Axis]: Eisner Advisory Group LLC, First lien
Spread		5.25%	[8],[9]	5.25%	[10],[11]
Interest Rate		10.17%	[8],[9]	9.69%	[10],[11]
Principal Amount, Par Value		$ 1,928	[9]	$ 1,933	[11]
Cost		1,902	[9]	1,906	[11]
Fair Value		$ 1,930	[9]	$ 1,847	[11]
Percent of Net Assets		2.29%		1.42%
Investment, Identifier [Axis]: FS WhiteWater Borrower, LLC, First lien - Drawn
Spread		6%	[7],[8],[12]	6%	[10],[11],[13]
Interest Rate		10.82%	[7],[8],[12]	10.54%	[10],[11],[13]
Principal Amount, Par Value		$ 1,304	[7],[12]	$ 491	[11],[13]
Cost		1,293	[7],[12]	486	[11],[13]
Fair Value		$ 1,291	[7],[12]	$ 486	[11],[13]
Percent of Net Assets		1.54%		0.38%
Investment, Identifier [Axis]: FS WhiteWater Borrower, LLC, First lien - Undrawn
Principal Amount, Par Value		$ 3,487	[7],[12]	$ 4,302	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (35)	[7],[12]	$ (43)	[11],[13]
Percent of Net Assets		(0.04%)		(0.03%)
Investment, Identifier [Axis]: Foreside Financial Group, LLC, First lien
Spread	[10],[11]			5.50%
Interest Rate	[10],[11]			9.88%
Principal Amount, Par Value	[11]			$ 3,614
Cost	[11]			3,582
Fair Value	[11]			$ 3,578
Percent of Net Assets				2.75%
Investment, Identifier [Axis]: Foreside Financial Group, LLC, First lien - Undrawn 1
Principal Amount, Par Value		$ 222	[7],[12]	$ 222	[11],[13]
Cost		(2)	[7],[12]	(2)	[11],[13]
Fair Value		(3)	[7],[12]	(2)	[11],[13]
Investment, Identifier [Axis]: Foreside Financial Group, LLC, First lien - Undrawn 2
Principal Amount, Par Value		506	[7],[12]	521	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (5)	[7],[12]	(5)	[11],[13]
Investment, Identifier [Axis]: Foreside Financial Group, LLC, First lien 1
Spread	[7],[8],[9]	5.50%
Interest Rate	[7],[8],[9]	10.54%
Principal Amount, Par Value	[7],[9]	$ 3,605
Cost	[7],[9]	3,576
Fair Value	[7],[9]	$ 3,569
Investment, Identifier [Axis]: Foreside Financial Group, LLC, First lien 2
Spread	[7],[8]	5.50%
Interest Rate	[7],[8]	10.54%
Principal Amount, Par Value	[7]	$ 15
Cost	[7]	13
Fair Value	[7]	$ 15
Investment, Identifier [Axis]: Fortis Solutions Group, LLC, First lien - Drawn
Spread	[7],[8],[12]	5.50%
Interest Rate	[7],[8],[12]	10.34%
Principal Amount, Par Value	[7],[12]	$ 36
Cost	[7],[12]	36
Fair Value	[7],[12]	$ 36
Percent of Net Assets		0.04%
Investment, Identifier [Axis]: Fortis Solutions Group, LLC, First lien - Undrawn
Principal Amount, Par Value		$ 5,936	[7],[12]	5,971	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (131)	[7],[12]	$ (140)	[11],[13]
Percent of Net Assets		(0.16%)		(0.11%)
Investment, Identifier [Axis]: Foundational Education Group, Inc., Second lien
Spread		6.50%	[7],[8],[9]	6.50%	[10],[11]
Interest Rate		11.66%	[7],[8],[9]	11.34%	[10],[11]
Principal Amount, Par Value		$ 7,333	[7],[9]	$ 6,332	[11]
Cost		6,273	[7],[9]	5,442	[11]
Fair Value		$ 6,886	[7],[9]	$ 5,858	[11]
Percent of Net Assets		8.18%		4.51%
Investment, Identifier [Axis]: Groundworks, LLC, First lien
Spread	[8],[9]	6.50%
Interest Rate	[8],[9]	11.36%
Principal Amount, Par Value	[9]	$ 2,908
Cost	[9]	2,866
Fair Value	[9]	$ 2,865
Percent of Net Assets		3.41%
Investment, Identifier [Axis]: Groundworks, LLC, First lien - Undrawn 1
Principal Amount, Par Value	[12]	$ 181
Cost	[12]	(3)
Fair Value	[12]	(3)
Investment, Identifier [Axis]: Groundworks, LLC, First lien - Undrawn 2
Principal Amount, Par Value	[12]	531
Cost	[12]	0
Fair Value	[12]	$ (8)
Investment, Identifier [Axis]: IMO Investor Holdings, Inc., First lien
Spread		6%	[7],[8],[9]	6%	[10],[11]
Interest Rate		10.62%	[7],[8],[9]	10.62%	[10],[11]
Principal Amount, Par Value		$ 4,581	[7],[9]	$ 4,593	[11]
Cost		4,541	[7],[9]	4,551	[11]
Fair Value		$ 4,490	[7],[9]	$ 4,547	[11]
Investment, Identifier [Axis]: IMO Investor Holdings, Inc., First lien - Drawn
Spread		6%	[7],[8],[12]	6%	[10],[11],[13]
Interest Rate		10.78%	[7],[8],[12]	10.61%	[10],[11],[13]
Principal Amount, Par Value		$ 214	[7],[12]	$ 104	[11],[13]
Cost		212	[7],[12]	104	[11],[13]
Fair Value		210	[7],[12]	103	[11],[13]
Investment, Identifier [Axis]: IMO Investor Holdings, Inc., First lien - Undrawn 1
Principal Amount, Par Value		334	[7],[12]	444	[11],[13]
Cost		(3)	[7],[12]	(5)	[11],[13]
Fair Value		(6)	[7],[12]	(4)	[11],[13]
Investment, Identifier [Axis]: IMO Investor Holdings, Inc., First lien - Undrawn 2
Principal Amount, Par Value		1,096	[7],[12]	1,096	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (22)	[7],[12]	$ (12)	[11],[13]
Investment, Identifier [Axis]: Infogain Corporation, First lien
Spread		5.75%	[7],[8],[9]	5.75%	[10],[11]
Interest Rate		10.59%	[7],[8],[9]	10.17%	[10],[11]
Principal Amount, Par Value		$ 2,743	[7],[9]	$ 2,750	[11]
Cost		2,719	[7],[9]	2,724	[11]
Fair Value		$ 2,722	[7],[9]	$ 2,698	[11]
Investment, Identifier [Axis]: Infogain Corporation, Subordinated
Spread		8.25%	[7],[8]	8.25%	[10],[11]
Interest Rate		13.25%	[7],[8]	12.93%	[10],[11]
Principal Amount, Par Value		$ 3,150	[7]	$ 3,150	[11]
Cost		3,113	[7]	3,112	[11]
Fair Value		$ 3,040	[7]	$ 3,077	[11]
Investment, Identifier [Axis]: KPSKY Acquisition Inc., First lien - Drawn
Spread		5.50%	[7],[8],[12]	4.50%	[10],[11],[13]
Interest Rate		10.41%	[7],[8],[12]	12%	[10],[11],[13]
Principal Amount, Par Value		$ 419	[7],[12]	$ 221	[11],[13]
Cost		416	[7],[12]	219	[11],[13]
Fair Value		$ 400	[7],[12]	$ 211	[11],[13]
Percent of Net Assets		0.48%		0.16%
Investment, Identifier [Axis]: KPSKY Acquisition Inc., First lien - Undrawn
Principal Amount, Par Value		$ 1,353	[7],[12]	$ 1,553	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (63)	[7],[12]	$ (69)	[11],[13]
Percent of Net Assets		(0.07%)		(0.05%)
Investment, Identifier [Axis]: KWOR Acquisition, Inc., First lien
Spread		5.25%	[7],[8],[9]	5.25%	[10],[11]
Interest Rate		10.09%	[7],[8],[9]	9.64%	[10],[11]
Principal Amount, Par Value		$ 1,931	[7],[9]	$ 1,940	[11]
Cost		1,914	[7],[9]	1,922	[11]
Fair Value		$ 1,922	[7],[9]	$ 1,922	[11]
Percent of Net Assets		2.28%		1.48%
Investment, Identifier [Axis]: KWOR Acquisition, Inc., First lien - Undrawn
Principal Amount, Par Value		$ 2,055	[7],[12]	$ 2,055	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (9)	[7],[12]	$ (20)	[11],[13]
Percent of Net Assets		(0.01%)		(0.02%)
Investment, Identifier [Axis]: Kaseya Inc., First lien
Spread		5.75%	[7],[8],[9]	5.75%	[10],[11]
Interest Rate		10.65%	[7],[8],[9]	10.33%	[10],[11]
Principal Amount, Par Value		$ 7,798	[5],[7],[9]	$ 7,798	[6],[11]
Cost		7,746	[5],[7],[9]	7,744	[6],[11]
Fair Value		$ 7,740	[5],[7],[9]	$ 7,684	[6],[11]
Percent of Net Assets		9.20%		5.91%
Investment, Identifier [Axis]: Kaseya Inc., First lien - Undrawn 1
Principal Amount, Par Value		$ 476	[7],[12]	$ 476	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		(4)	[7],[12]	(7)	[11],[13]
Investment, Identifier [Axis]: Kaseya Inc., First lien - Undrawn 2
Principal Amount, Par Value		476	[7],[12]	476	[11],[13]
Cost		(3)	[7],[12]	(3)	[11],[13]
Fair Value		$ (4)	[7],[12]	$ (7)	[11],[13]
Investment, Identifier [Axis]: Knockout Intermediate Holdings I Inc., Preferred shares
Principal Amount, Shares (in shares)		838	[5],[7]	789	[6],[11]
Cost		$ 828	[5],[7]	$ 779	[6],[11]
Fair Value		$ 827	[5],[7]	$ 763	[6],[11]
Percent of Net Assets		0.98%		0.59%
Investment, Identifier [Axis]: Nielsen Consumer Inc., First lien 1
Spread	[8],[9]	6.25%
Interest Rate	[8],[9]	11.06%
Principal Amount, Par Value	[9]	$ 6,735
Cost	[9]	5,995
Fair Value	[9]	$ 5,944
Investment, Identifier [Axis]: Nielsen Consumer Inc., First lien 2
Spread	[8],[9]	6.25%
Interest Rate	[8],[9]	11.06%
Principal Amount, Par Value	[9]	$ 3,265
Cost	[9]	2,906
Fair Value	[9]	$ 2,881
Investment, Identifier [Axis]: Oranje Holdco, Inc., First lien
Spread	[7],[8]	7.75%
Interest Rate	[7],[8]	12.43%
Principal Amount, Par Value	[7]	$ 11,667
Cost	[7]	11,525
Fair Value	[7]	$ 11,611
Percent of Net Assets		13.80%
Investment, Identifier [Axis]: Oranje Holdco, Inc., First lien - Undrawn
Principal Amount, Par Value	[7],[12]	$ 1,458
Cost	[7],[12]	(18)
Fair Value	[7],[12]	$ (7)
Percent of Net Assets		(0.01%)
Investment, Identifier [Axis]: PPV Intermediate Holdings LLC, First lien
Spread	[10],[11]			5.75%
Interest Rate	[10],[11]			9.11%
Principal Amount, Par Value	[11]			$ 5,800
Cost	[11]			5,745
Fair Value	[11]			$ 5,687
Investment, Identifier [Axis]: PPV Intermediate Holdings LLC, First lien - Drawn
Spread	[10],[11],[13]			5.75%
Interest Rate	[10],[11],[13]			10.31%
Principal Amount, Par Value	[11],[13]			$ 115
Cost	[11],[13]			114
Fair Value	[11],[13]			113
Investment, Identifier [Axis]: PPV Intermediate Holdings LLC, First lien - Undrawn 1
Principal Amount, Par Value	[11],[13]			311
Cost	[11],[13]			(2)
Fair Value	[11],[13]			(6)
Investment, Identifier [Axis]: PPV Intermediate Holdings LLC, First lien - Undrawn 2
Principal Amount, Par Value	[11],[13]			775
Cost	[11],[13]			0
Fair Value	[11],[13]			$ (15)
Investment, Identifier [Axis]: PPV Intermediate Holdings, LLC First lien 1
Spread	[7],[8],[9]	5.75%
Interest Rate	[7],[8],[9]	10.85%
Principal Amount, Par Value	[7],[9]	$ 6,023
Cost	[7],[9]	5,974
Fair Value	[7],[9]	5,893
Investment, Identifier [Axis]: PPV Intermediate Holdings, LLC, First lien - Undrawn 1
Principal Amount, Par Value	[7],[12]	270
Cost	[7],[12]	0
Fair Value	[7],[12]	(6)
Investment, Identifier [Axis]: PPV Intermediate Holdings, LLC, First lien - Undrawn 2
Principal Amount, Par Value	[7],[12]	426
Cost	[7],[12]	(4)
Fair Value	[7],[12]	$ (9)
Investment, Identifier [Axis]: PPV Intermediate Holdings, LLC, First lien 2
Spread	[7],[8]	5.75%
Interest Rate	[7],[8]	10.85%
Principal Amount, Par Value	[7]	$ 281
Cost	[7]	272
Fair Value	[7]	$ 275
Investment, Identifier [Axis]: Project Power Buyer, LLC, First lien
Spread	[7],[8],[9]	7%
Interest Rate	[7],[8],[9]	11.90%
Principal Amount, Par Value	[7],[9]	$ 3,580
Cost	[7],[9]	3,530
Fair Value	[7],[9]	$ 3,527
Percent of Net Assets		4.19%
Investment, Identifier [Axis]: Project Power Buyer, LLC, First lien - Undrawn
Principal Amount, Par Value	[7],[12]	$ 184
Cost	[7],[12]	(3)
Fair Value	[7],[12]	$ (3)
Percent of Net Assets		(0.00%)
Investment, Identifier [Axis]: Project Ruby Ultimate Parent Corp., First lien
Spread		5.75%	[7],[8],[9]	5.75%	[10],[11]
Interest Rate		10.56%	[7],[8],[9]	10.07%	[10],[11]
Principal Amount, Par Value		$ 4,975	[7],[9]	$ 4,988	[11]
Cost		4,909	[7],[9]	4,918	[11]
Fair Value		$ 5,058	[7],[9]	$ 4,838	[11]
Percent of Net Assets		6.01%		3.72%
Investment, Identifier [Axis]: Radwell Parent, LLC, First lien
Spread		6.75%	[7],[8],[9]	6.75%	[10],[11]
Interest Rate		11.65%	[7],[8],[9]	11.33%	[10],[11]
Principal Amount, Par Value		$ 5,533	[7],[9]	$ 5,547	[11]
Cost		5,454	[7],[9]	5,465	[11]
Fair Value		$ 5,450	[7],[9]	$ 5,464	[11]
Percent of Net Assets				4.20%
Investment, Identifier [Axis]: Radwell Parent, LLC, First lien - Drawn
Spread	[7],[8],[12]	6.75%
Interest Rate	[7],[8],[12]	11.56%
Principal Amount, Par Value	[7],[12]	$ 55
Cost	[7],[12]	55
Fair Value	[7],[12]	55
Investment, Identifier [Axis]: Radwell Parent, LLC, First lien - Undrawn
Principal Amount, Par Value		361	[7],[12]	$ 416	[11],[13]
Cost		(5)	[7],[12]	(6)	[11],[13]
Fair Value		$ 0	[7],[12]	$ (3)	[11],[13]
Percent of Net Assets		0%		(0.00%)
Investment, Identifier [Axis]: Smile Doctors LLC, First lien - Drawn
Spread		5.75%	[7],[8],[12]	5.75%	[10],[11],[13]
Interest Rate		10.79%	[7],[8],[12]	10.24%	[10],[11],[13]
Principal Amount, Par Value		$ 3,487	[7],[12]	$ 2,152	[11],[13]
Cost		3,456	[7],[12]	2,132	[11],[13]
Fair Value		$ 3,463	[7],[12]	$ 2,141	[11],[13]
Percent of Net Assets		4.12%		1.65%
Investment, Identifier [Axis]: Smile Doctors LLC, First lien - Undrawn
Principal Amount, Par Value		$ 1,499	[7],[12]	$ 2,843	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (10)	[7],[12]	$ (14)	[11],[13]
Percent of Net Assets		(0.01%)		(0.01%)
Investment, Identifier [Axis]: Sun Acquirer Corp., First lien - Undrawn
Principal Amount, Par Value		$ 5,000	[7],[12]	$ 5,000	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		$ (55)	[7],[12]	$ (84)	[11],[13]
Percent of Net Assets		(0.07%)		(0.06%)
Investment, Identifier [Axis]: Syndigo LLC, Second lien
Spread		8%	[7],[8],[9]	8%	[10],[11]
Interest Rate		13.21%	[7],[8],[9]	13.21%	[10],[11]
Principal Amount, Par Value		$ 1,475	[7],[9]	$ 1,475	[11]
Cost		1,066	[7],[9]	1,051	[11]
Fair Value		$ 1,382	[7],[9]	$ 1,381	[11]
Percent of Net Assets		1.64%		1.06%
Investment, Identifier [Axis]: Trident Bidco Limited, First lien 1
Spread		5%	[7],[8],[9]	5.25%	[10],[11]
Interest Rate		9.55%	[7],[8],[9]	9.07%	[10],[11]
Principal Amount, Par Value		$ 3,711	[7],[9]	$ 3,711	[11]
Cost		3,679	[7],[9]	3,677	[11]
Fair Value		$ 3,634	[7],[9]	$ 3,631	[11]
Investment, Identifier [Axis]: Trident Bidco Limited, First lien 2
Spread		5%	[7],[8],[9]	5.25%	[10],[11]
Interest Rate		9.55%	[7],[8],[9]	9.07%	[10],[11]
Principal Amount, Par Value		$ 664	[7],[9]	$ 664	[11]
Cost		657	[7],[9]	657	[11]
Fair Value		$ 650	[7],[9]	$ 649	[11]
Investment, Identifier [Axis]: Virtusa Corporation, Subordinated
Spread		7.13%	[8]	7.13%	[10]
Interest Rate		7.13%	[8]	7.13%	[10]
Principal Amount, Par Value		$ 10,023		$ 10,023
Cost		7,761		7,694
Fair Value		$ 7,889		$ 7,653
Percent of Net Assets		9.38%		5.89%
Investment, Identifier [Axis]: WatchGuard Technologies, Inc., First lien
Spread		5.25%	[8],[9]	5.25%	[10]
Interest Rate		10.11%	[8],[9]	9.57%	[10]
Principal Amount, Par Value		$ 3,769	[9]	$ 3,778
Cost		3,656	[9]	3,661
Fair Value		$ 3,580	[9]	$ 3,625
Percent of Net Assets		4.26%		2.79%
Investment, Identifier [Axis]: Xactly Corporation, First lien
Spread	[7],[8]	7.25%
Interest Rate	[7],[8]	11.93%
Principal Amount, Par Value	[7]	$ 6,547
Cost	[7]	6,513
Fair Value	[7]	$ 6,547
Percent of Net Assets		7.78%
Investment, Identifier [Axis]: iCIMS, Inc., First lien
Spread		3.38%	[7],[8],[9],[14]	3.38%	[10],[11],[15]
PIK		3.88%	[7],[8],[9],[14]	3.88%	[10],[11],[15]
Interest Rate		12.05%	[7],[8],[9],[14]	11.52%	[10],[11],[15]
Principal Amount, Par Value		$ 9,685	[7],[9]	$ 9,587	[11]
Cost		9,609	[7],[9]	9,508	[11]
Fair Value		$ 9,633	[7],[9]	$ 9,504	[11]
Percent of Net Assets		11.45%		7.31%
Investment, Identifier [Axis]: iCIMS, Inc., First lien - Undrawn 1
Principal Amount, Par Value		$ 2,448	[7],[12]	$ 2,546	[11],[13]
Cost		0	[7],[12]	0	[11],[13]
Fair Value		0	[7],[12]	0	[11],[13]
Investment, Identifier [Axis]: iCIMS, Inc., First lien - Undrawn 2
Principal Amount, Par Value		913	[7],[12]	914	[11],[13]
Cost		(7)	[7],[12]	(8)	[11],[13]
Fair Value		$ (5)	[7],[12]	$ (8)	[11],[13]
[1]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.[2]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.[3]Indicates assets that the Company deems to be "non-qualifying assets" under Section 55(a) of the Investment Company Act of 1940, as amended. Qualifying assets must represent at least 70.0% of the Company's total assets at the time of acquisition of any additional non-qualifying assets. As of March 31, 2023, 8.36% of the Company's total assets are represented by investments at fair value that are considered non-qualifying assets.[4]Indicates assets that the Company deems to be "non-qualifying assets" under Section 55(a) of the 1940 Act. Qualifying assets must represent at least 70.0% of the Company's total assets at the time of acquisition of any additional non-qualifying assets. As of December 31, 2022, 5.91% of the Company's total assets are represented by investments at fair value that are considered non-qualifying assets.[5]The Company holds preferred equity in Knockout Intermediate Holdings I Inc. and a first lien term loan, a first lien revolver and a first lien delayed draw in Kaseya, Inc., a wholly-owned subsidiary of Knockout Intermediate Holdings I, Inc. The preferred equity is entitled to receive cumulative preferential dividends at a rate of 11.75% per annum.[6]The Company holds preferred equity in Knockout Intermediate Holdings I Inc. and a first lien term loan, a first lien revolver and a first lien delayed draw in Kaseya, Inc., a wholly-owned subsidiary of Knockout Intermediate Holdings I, Inc. The preferred equity is entitled to receive cumulative preferential dividends at a rate of 11.75% per annum.[7] The fair value of the Company's investment is determined using unobservable inputs that are significant to the overall fair value measurement. See Note 4. Fair Value , for details.

Consolidated Schedule of Inve_2

Consolidated Schedule of Investments (Parenthetical)	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Investments at fair value that are non-qualifying assets as a percentage of total assets	8.36%	5.91%
Investment, Identifier [Axis]: Knockout Intermediate Holdings I Inc., Preferred shares
Preferred equity dividend rate	11.75%	11.75%

Formation and Business Purpose

Formation and Business Purpose	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Formation and Business Purpose	Formation and Business Purpose New Mountain Guardian IV BDC, L.L.C. (the "Company") is a Delaware limited liability company formed on March 18, 2022. 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 U.S. federal income tax purposes, and intends to qualify annually thereafter, as a regulated investment company ("RIC") under Subchapter M of the Internal Revenue Code of 1986, as amended (the "Code"). New Mountain Finance Advisers BDC, L.L.C. (the "Investment Adviser") 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. 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. The Company conducted a private offering (the "Private Offering") of units of the Company's limited liability company interests (the "Units") to investors in reliance on exemptions from the registration requirements of the Securities Act of 1933, as amended (the "Securities Act"). Units will be offered for subscription continuously throughout the Closing Period (as defined below). Each investor in the Private Offering made a capital commitment (each, a "Capital Commitment") to purchase Units pursuant to a subscription agreement entered into with the Company (a "Subscription Agreement"). The Company expects closings of the Private Offering will occur, from time to time, in the Investment Adviser's sole discretion, during the 24-month period following the initial closing of Capital Commitments, which occurred on May 4, 2022 (the "Closing Period"). The Company may accept and draw down on Capital Commitments from investors throughout the Closing Period and may draw down on Capital Commitments after the Closing Period. The Company commenced loan origination and investment activities contemporaneously with the initial drawdown from investors in the Private Offering, which occurred on May 9, 2022 (the "Initial Drawdown"). The "Investment Period" began on May 4, 2022 and will continue until May 4, 2028, the four-year anniversary of the end of the Closing Period. The term of the Company is until May 4, 2030, six years from the end of the Closing Period, subject to (i) a one year extension as determined by the Investment Adviser in its sole discretion and (ii) an additional one year extension as determined by the Company's board of directors. The Company established New Mountain Guardian IV SPV, L.L.C. (“GIV SPV”) on July 26, 2022 as a wholly-owned direct subsidiary, whose assets are used to secure GIV SPV's credit facility. The Company established New Mountain Guardian IV Issuer SPV, L.L.C. ("GIV Issuer SPV") on October 28, 2022 as a wholly-owned direct subsidiary. As of March 31, 2023, there were no assets held by GIV Issuer SPV. The Company's investment objective is to generate current income and capital appreciation primarily by investing in or originating debt investments in companies that the Investment Adviser believes are "defensive growth" companies in non-cyclical industry niches where the Investment Adviser has developed strong proprietary research and operational advantages. The Company makes investments through both primary originations and opportunistic open-market secondary purchases. The Company predominantly targets loans to, and invests in, U.S. middle market businesses. The Company defines middle market businesses as those businesses with annual earnings before interest, taxes, depreciation, and amortization ("EBITDA") between $10,000 and $200,000. In some cases, the Company's investments may also include equity interests. The primary focus is in the debt of defensive growth companies, which are defined as generally exhibiting the following characteristics: (i) sustainable secular growth drivers, (ii) high barriers to competitive entry, (iii) high free cash flow after capital expenditure and working capital needs, (iv) high returns on assets and (v) niche market dominance. The Company invests across the capital structure of middle market companies, primarily targeting first lien and unitranche loans and to a lesser extent second lien and passive preferred stock investments where the Investment Adviser has a high degree of conviction in the business. Unitranche loans combine characteristics of traditional first lien senior secured loans as well as second lien and subordinated loans to the extent we invest in the “last out” tranche. In some cases, our investments may also include equity interests. As of March 31, 2023, the Company's top five industry concentrations were software, business services, healthcare, consumer services and education.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of accounting —The Company's consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States ("GAAP"). The Company is an investment company following accounting and reporting guidance in Accounting Standards Codification Topic 946, Financial Services — Investment Companies ("ASC 946"). The Company consolidates its wholly-owned direct subsidiaries GIV SPV and GIV Issuer SPV. The Company's consolidated financial statements reflect all adjustments and reclassifications which, in the opinion of management, are necessary for the fair presentation of the results of operations and financial condition for the period(s) presented. All intercompany transactions have been eliminated. Revenues are recognized when earned and expenses when incurred. The financial results of the Company's portfolio investments are not consolidated in the financial statements. The Company's interim consolidated financial statements are prepared in accordance with GAAP and pursuant to the requirements for reporting on Form 10-Q and Article 6 and 10 of Regulation S-X. Accordingly, the Company’s interim consolidated financial statements do not include all of the information and notes required by GAAP for annual financial statements. In the opinion of management, all adjustments, consisting solely of normal recurring accruals considered necessary for the fair presentation of financial statements for the interim period, have been included. The current period's results of operations will not necessarily be indicative of results that ultimately may be achieved for the fiscal year ending December 31, 2023. Investments —The Company applies fair value accounting in accordance with GAAP. Fair value is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Investments are reflected on the Company's Consolidated Statements of Assets, Liabilities and Members' Capital at fair value, with changes in unrealized gains and losses resulting from changes in fair value reflected in the Company's Consolidated Statement of Operations as "Net change in unrealized appreciation (depreciation) of investments" and realizations on portfolio investments reflected in the Company's Consolidated Statement of Operations as "Net realized gains (losses) on investments". The Company values its assets on a quarterly basis, or more frequently if required under the 1940 Act. In all cases, the Company's board of directors is ultimately and solely responsible for determining the fair value of the Company's portfolio investments on a quarterly basis in good faith, including investments that are not publicly traded, those whose market prices are not readily available and any other situation where its portfolio investments require a fair value determination. Security transactions are accounted for on a trade date basis. The Company's quarterly valuation procedures are set forth in more detail below: (1) Investments for which market quotations are readily available on an exchange are valued at such market quotations based on the closing price indicated from independent pricing services. (2) Investments for which indicative prices are obtained from various pricing services and/or brokers or dealers are valued through a multi-step valuation process, as described below, to determine whether the quote(s) obtained is representative of fair value in accordance with GAAP. a. Bond quotes are obtained through independent pricing services. Internal reviews are performed by the investment professionals of the Investment Adviser to ensure that the quote obtained is representative of fair value in accordance with GAAP and, if so, the quote is used. If the Investment Adviser is unable to sufficiently validate the quote(s) internally and if the investment's par value or its fair value exceeds the materiality threshold, the investment is valued similarly to those assets with no readily available quotes (see (3) below); and b. For investments other than bonds, the Company looks at the number of quotes readily available and performs the following procedures: i. Investments for which two or more quotes are received from a pricing service are valued using the mean of the mean of the bid and ask of the quotes obtained. The Company will evaluate the reasonableness of the quote, and if the quote is determined to not be representative of fair value, the Company will use one or more of the methodologies outlined below to determine fair value; and ii. Investments for which one quote is received from a pricing service are validated internally. The investment professionals of the Investment Adviser analyze the market quotes obtained using an array of valuation methods (further described below) to validate the fair value. If the Investment Adviser is unable to sufficiently validate the quote internally and if the investment's par value or its fair value exceeds the materiality threshold, the investment is valued similarly to those assets with no readily available quotes (see (3) below). (3) Investments for which quotations are not readily available through exchanges, pricing services, brokers, or dealers are valued through a multi-step valuation process: a. Each portfolio company or investment is initially valued by the investment professionals of the Investment Adviser responsible for the credit monitoring; b. Preliminary valuation conclusions will then be documented and discussed with the Company's senior management; c. If an investment falls into (3) above for four consecutive quarters and if the investment's par value or its fair value exceeds the materiality threshold, then at least once each fiscal year, the valuation for each portfolio investment for which the Company does not have a readily available market quotation will be reviewed by an independent valuation firm engaged by the Company's board of directors; and d. When deemed appropriate by the Company's management, an independent valuation firm may be engaged to review and value investment(s) of a portfolio company, without any preliminary valuation being performed by the Investment Adviser. The investment professionals of the Investment Adviser will review and validate the value provided. For investments in revolving credit facilities and delayed draw commitments, the cost basis of the funded investments purchased is offset by any costs/netbacks received for any unfunded portion on the total balance committed. The fair value is also adjusted for the price appreciation or depreciation on the unfunded portion. As a result, the purchase of a commitment not completely funded may result in a negative fair value until it is called and funded. The values assigned to investments are based upon available information and do not necessarily represent amounts which might ultimately be realized, since such amounts depend on future circumstances and cannot be reasonably determined until the individual positions are liquidated. Due to the inherent uncertainty of determining the fair value of investments that do not have a readily available market value, the fair value of the Company's investments may fluctuate from period to period and the fluctuations could be material. See Note 3. Investments , for further discussion relating to investments. Cash and cash equivalents —Cash and cash equivalents include cash and short-term, highly liquid investments. The Company defines cash equivalents as securities that are readily convertible into known amounts of cash and so near maturity that there is insignificant risk of changes in value. These securities have original maturities of three months or less. The Company did not hold any cash equivalents as of March 31, 2023 and December 31, 2022. Revenue recognition Sales and paydowns of investments: Realized gains and losses on investments are determined on the specific identification method. Interest and dividend income: Interest income, including amortization of premium and discount using the effective interest method, is recorded on the accrual basis and periodically assessed for collectability. Interest income also includes interest earned from cash on hand. Upon the prepayment of a loan or debt security, any prepayment penalties are recorded as part of interest income. The Company has loans and certain preferred equity investments in its portfolio that contain a payment-in-kind ("PIK") interest or dividend provision. PIK interest and dividends are accrued and recorded as income at the contractual rates, if deemed collectible. The PIK interest and dividends are added to the principal or share balances on the capitalization dates and are generally due at maturity or when redeemed by the issuer. For the three months ended March 31, 2023, the Company recognized PIK dividends from investments of $25 and PIK interest from investments of $93. Dividend income on preferred securities is recorded as dividend income on an accrual basis to the extent that such amounts are deemed collectible. Non-accrual income: Investments are placed on non-accrual status when principal or interest payments are past due for 30 days or more and when there is reasonable doubt that principal or interest will be collected. Accrued cash and un-capitalized PIK interest or dividends are reversed when an investment is placed on non-accrual status. Previously capitalized PIK interest or dividends are not reversed when an investment is placed on non-accrual status. Interest or dividend payments received on non-accrual investments may be recognized as income or applied to principal depending upon management's judgment of the ultimate collectability. Non-accrual investments are restored to accrual status when past due principal and interest is paid and, in management's judgment, are likely to remain current. As of March 31, 2023 and December 31, 2022, no investments were on non-accrual status. Fee income: Fee income represents delayed compensation, revolver fees, amendment fees, assignment fees, upfront fees and other miscellaneous fees received and are typically non-recurring in nature. Delayed compensation is income earned from counterparties on trades that do not settle within a set number of business days after the trade date. Fee income may also include fees from bridge loans. The Company may from time to time enter into bridge financing commitments, an obligation to provide interim financing to a counterparty until permanent credit can be obtained. These commitments are short-term in nature and may expire unfunded. A fee is received by the Company for providing such commitments. Structuring fees and upfront fees are recognized as income when earned, usually when paid at the closing of the investment, and are non-refundable. Income received in exchange for the provision of services such as recurring administration services are also recognized as fee income in the period in which it was earned. Interest and other financing expenses —Interest and other financing fees are recorded on an accrual basis by the Company. See Note 6. Borrowings , for details. Organizational expenses —Organizational expenses include costs and expenses incurred in connection with the formation and organization of the Company and are expensed as incurred in the Consolidated Statement of Operations. Any organizational and offering expenses paid by the Company in excess of the lesser of $2,500 or 0.50% of the aggregate Capital Commitments will be applied as a reduction to the base management fee paid to the Investment Adviser and cannot be recouped by the Investment Adviser. Deferred offering costs —The Company's deferred offering costs consists of fees and expenses incurred in connection with the offering of the Company's Units. Upon the issuance of Units, deferred offering costs are then amortized into Organizational and Offering Expenses on the Consolidated Statement of Operations on a straight line basis over a period of 12 months beginning on the date of commencement of operations. Deferred offering costs are included on the Company’s Consolidated Statements of Assets, Liabilities and Members' Capital until amortized. Deferred financing costs —The deferred financing costs of the Company consist of capitalized expenses related to the origination and amending of the Company's borrowings. The Company amortizes these costs into expense over the stated life of the related borrowing. See Note 6. Borrowings , for details. Income taxes —The Company was treated as a disregarded entity wholly owned by New Mountain Finance Advisers, L.L.C. for the period beginning with the date of its inception on March 18, 2022 through May 5, 2022. The Company intends to elect to be treated as a RIC for U.S. federal income tax purposes under Subchapter M of the Code with the filing of its first tax return for the year ending December 31, 2022, and thereafter intends to comply with the requirements to qualify and maintain its status as a RIC annually. As a RIC, the Company is not subject to U.S. federal income tax on the portion of taxable income and gains timely distributed to its unitholders. To qualify and be subject to tax treatment as a RIC, the Company is required to meet certain income and asset diversification tests in addition to timely distributing at least 90.0% of its investment company taxable income, as defined by the Code. Since U.S. federal income tax regulations differ from GAAP, distributions in accordance with tax regulations may differ from net investment income and realized gains recognized for financial reporting purposes. Differences between taxable income and the results of operations for financial reporting purposes may be permanent or temporary in nature. Permanent differences are reclassified among capital accounts in the consolidated financial statements to reflect their tax character. Differences in classification may also result from the treatment of short-term gains as ordinary income for U.S. federal income tax purposes. For U.S. federal income tax purposes, distributions paid to unitholders of the Company are reported as ordinary income, return of capital, long term capital gains or a combination thereof. The Company will be subject to a 4.0% nondeductible federal excise tax on certain undistributed income unless the Company distributes, in a timely manner as required by the Code, an amount at least equal to the sum of (1) 98.0% of its respective net ordinary income earned for the calendar year and (2) 98.2% of its respective capital gain net income for the one-year period ending October 31 in the calendar year. Distributions —Distributions to the Company's unitholders are recorded on the record date as set by the Company's board of directors. The Company intends to make timely distributions to its unitholders that will be sufficient to enable the Company to qualify and maintain its status as a RIC. The Company intends to distribute approximately all of its net investment income on a quarterly basis and substantially all of its taxable income on an annual basis, except that the Company may retain certain net capital gains for reinvestment. Earnings per Unit —The Company's earnings per unit ("EPU") amounts have been computed based on the weighted-average number of Units outstanding for the period. Basic EPU is computed by dividing net increase (decrease) in members' capital resulting from operations by the weighted average number of Units outstanding during the period of computation. Diluted EPU is computed by dividing net increase (decrease) in members' capital resulting from operations by the weighted average number of Units assuming all potential Units had been issued, and its related net impact to members' capital accounted for, and the additional Units were dilutive. Diluted EPU reflects the potential dilution, using the as-if-converted method for convertible debt, which could occur if all potentially dilutive securities were exercised. Foreign securities —The accounting records of the Company are maintained in U.S. dollars. Investment securities denominated in foreign currencies are translated into U.S. dollars based on the rate of exchange of such currencies on the date of valuation. Purchases and sales of investment securities and income and expense items denominated in foreign currencies are translated into U.S. dollars based on the rate of exchange of such currencies on the respective dates of the transactions. The Company does not isolate that portion of the results of operations resulting from changes in foreign exchange rates on investments from the fluctuations arising from changes in market prices of securities held. Such fluctuations are included with "Net change in unrealized appreciation (depreciation) of investments" and "Net realized gains (losses) on investments" in the Company's Consolidated Statement of Operations. Investments denominated in foreign currencies may be negatively affected by movements in the rate of exchange between the U.S. dollar and foreign currencies. This movement is beyond the control of the Company and cannot be predicted. Use of estimates —The preparation of the Company's consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the Company's consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Changes in the economic environment, financial markets, and other metrics used in determining these estimates could cause actual results to differ from the estimates used, and the differences could be material.

Investments

Investments	3 Months Ended
	Mar. 31, 2023
Schedule of Investments [Abstract]
Investments	Investments At March 31, 2023, the Company's investments consisted of the following: Investment Cost and Fair Value by Type Cost Fair Value First lien $ 165,291 $ 164,905 Second lien 13,902 15,299 Subordinated 10,874 10,929 Equity and other 828 827 Total investments $ 190,895 $ 191,960 Investment Cost and Fair Value by Industry Cost Fair Value Software $ 104,533 $ 105,443 Business Services 46,122 45,926 Healthcare 16,127 16,157 Consumer Services 10,398 10,208 Education 6,273 6,886 Distribution & Logistics 5,540 5,410 Financial Services 1,902 1,930 Total investments $ 190,895 $ 191,960 At December 31, 2022, the Company's investments consisted of the following: Investment Cost and Fair Value by Type Cost Fair Value First lien $ 100,860 $ 99,866 Second lien 10,991 11,852 Subordinated 10,806 10,730 Equity and other 779 763 Total investments $ 123,436 $ 123,211 Investment Cost and Fair Value by Industry Cost Fair Value Software $ 60,274 $ 60,506 Business Services 29,285 29,035 Healthcare 14,727 14,506 Consumer Services 6,343 6,138 Education 5,442 5,858 Distribution & Logistics 5,459 5,321 Financial Services 1,906 1,847 Total investments $ 123,436 $ 123,211 As of March 31, 2023, the Company had unfunded commitments on revolving credit facilities of $9,948 and no unfunded commitments on bridge facilities. As of March 31, 2023, the Company had unfunded commitments in the form of delayed draws or other future funding commitments of $29,539. The unfunded commitments on revolving credit facilities and delayed draws are disclosed on the Company's Consolidated Schedule of Investments as of March 31, 2023. As of December 31, 2022, the Company had unfunded commitments on revolving credit facilities of $5,939 and no unfunded commitments on bridge facilities. As of December 31, 2022, the Company had unfunded commitments in the form of delayed draws or other future funding commitments of $30,263. The unfunded commitments on revolving credit facilities and delayed draws are disclosed on the Company's Consolidated Schedule of Investments as of December 31, 2022. Investment Risk Factors —First and second lien debt that the Company invests in is almost entirely rated below investment grade or may be unrated. Debt investments rated below investment grade are often referred to as "leveraged loans", "high yield" or "junk" debt investments, and may be considered "high risk" compared to debt investments that are rated investment grade. These debt investments are considered speculative because of the credit risk of the issuers. Such issuers are considered more likely than investment grade issuers to default on their payments of interest and principal, and such risk of default could reduce the members' capital and income distributions of the Company. In addition, some of the Company's debt investments will not fully amortize during their lifetime, which could result in a loss or a substantial amount of unpaid principal and interest due upon maturity. First and second lien debt may also lose significant market value before a default occurs. Furthermore, an active trading market may not exist for these first and second lien debt investments. This illiquidity may make it more difficult to value the debt. Subordinated debt is generally subject to similar risks as those associated with first and second lien debt, except that such debt is subordinated in payment and/or lower in lien priority. Subordinated debt is subject to the additional risk that the cash flow of the borrower and the property securing the debt, if any, may be insufficient to meet scheduled payments after giving effect to the senior secured and unsecured obligations of the borrower. The Company may directly invest in the equity of private companies or, in some cases, equity investments could be made in connection with a debt investment. Equity investments may or may not fluctuate in value, resulting in recognized realized gains or losses upon disposition.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Fair value is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosure ("ASC 820") establishes a fair value hierarchy that prioritizes and ranks the inputs to valuation techniques used in measuring investments at fair value. The hierarchy classifies the inputs used in measuring fair value into three levels as follows: Level I —Quoted prices (unadjusted) are available in active markets for identical investments and the Company has the ability to access such quotes as of the reporting date. The type of investments which would generally be included in Level I include active exchange-traded equity securities and exchange-traded derivatives. As required by ASC 820, the Company, to the extent that it holds such investments, does not adjust the quoted price for these investments, even in situations where the Company holds a large position and a sale could reasonably impact the quoted price. Level II —Pricing inputs are observable for the investments, either directly or indirectly, as of the reporting date, but are not the same as those used in Level I. Level II inputs include the following: • Quoted prices for similar assets or liabilities in active markets; • Quoted prices for identical or similar assets or liabilities in non-active markets (examples include corporate and municipal bonds, which trade infrequently); • Pricing models whose inputs are observable for substantially the full term of the asset or liability (examples include most over-the-counter derivatives, including foreign exchange forward contracts); and • Pricing models whose inputs are derived principally from or corroborated by observable market data through correlation or other means for substantially the full term of the asset or liability. Level III —Pricing inputs are unobservable for the investment and include situations where there is little, if any, market activity for the investment. The inputs used to measure fair value may fall into different levels. In all instances when the inputs fall within different levels of the hierarchy, the level within which the fair value measurement is categorized is based on the lowest level of input that is significant to the fair value measurement in its entirety. As such, a Level III fair value measurement may include inputs that are both observable and unobservable. Gains and losses for such assets categorized within the Level III table below may include changes in fair value that are attributable to both observable inputs and unobservable inputs. The inputs into the determination of fair value require significant judgment or estimation by management and consideration of factors specific to each investment. A review of the fair value hierarchy classifications is conducted on a quarterly basis. Changes in the observability of valuation inputs may result in the transfer of certain investments within the fair value hierarchy from period to period. The following table summarizes the levels in the fair value hierarchy that the Company's portfolio investments fall into as of March 31, 2023: Total Level I Level II Level III First lien $ 164,905 $ — $ 15,284 $ 149,621 Second lien 15,299 — 7,031 8,268 Subordinated 10,929 — 7,889 3,040 Equity and other 827 — — 827 Total investments $ 191,960 $ — $ 30,204 $ 161,756 The following table summarizes the levels in the fair value hierarchy that the Company's portfolio investments fall into as of December 31, 2022: Total Level I Level II Level III First lien $ 99,866 $ — $ 6,518 $ 93,348 Second lien 11,852 — 4,613 7,239 Subordinated 10,730 — 7,653 3,077 Equity and other 763 — — 763 Total investments $ 123,211 $ — $ 18,784 $ 104,427 The following table summarizes the changes in fair value of Level III portfolio investments for the three months ended March 31, 2023, as well as the portion of appreciation (depreciation) included in income attributable to unrealized appreciation (depreciation) related to those assets and liabilities still held by the Company at March 31, 2023: Total First Lien Second Lien Subordinated Equity and other Fair Value, December 31, 2022 $ 104,427 $ 93,348 $ 7,239 $ 3,077 $ 763 Total gains or losses included in earnings: Net change in unrealized appreciation (depreciation) of investments 1,011 804 229 (37) 15 Purchases, including revolver fundings 57,190 56,341 800 — 49 Proceeds from paydowns of investments (872) (872) — — — Fair Value, March 31, 2023 $ 161,756 $ 149,621 $ 8,268 $ 3,040 $ 827 Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period: $ 1,011 $ 804 $ 229 $ (37) $ 15 Except as noted in the tables above, there were no transfers in or out of Level I, II, or III during the three months ended March 31, 2023. Transfers into Level III occur as quotations obtained through pricing services are deemed not representative of fair value as of the balance sheet date and such assets are internally valued. As quotations obtained through pricing services are substantiated through additional market sources, investments are transferred out of Level III. In addition, transfers out of Level III and transfers into Level III occur based on the increase or decrease in the availability of certain observable inputs. Investments will be transferred into Level III from Level II and out of Level III into Level II at fair value as of the beginning of the period in which the reclassification occurred. The Company invests in revolving credit facilities. These investments are categorized as Level III investments as these assets are not actively traded and their fair values are often implied by the term loans of the respective portfolio companies. The Company generally uses the following framework when determining the fair value of investments where there are little, if any, market activity or observable pricing inputs. The Company typically determines the fair value of its performing debt investments utilizing an income approach. Additional consideration is given using a market based approach, as well as reviewing the overall underlying portfolio company's performance and associated financial risks. The following outlines additional details on the approaches considered: Company Performance, Financial Review, and Analysis: Prior to investment, as part of its due diligence process, the Company evaluates the overall performance and financial stability of the portfolio company. Post investment, the Company analyzes each portfolio company's current operating performance and relevant financial trends versus prior year and budgeted results, including, but not limited to, factors affecting its revenue and EBITDA growth, margin trends, liquidity position, covenant compliance and changes to its capital structure. The Company also attempts to identify and subsequently track any developments at the portfolio company, within its customer or vendor base or within the industry or the macroeconomic environment, generally, that may alter any material element of its original investment thesis. This analysis is specific to each portfolio company. The Company leverages the knowledge gained from its original due diligence process, augmented by this subsequent monitoring, to continually refine its outlook for each of its portfolio companies and ultimately form the valuation of its investment in each portfolio company. When an external event such as a purchase transaction, public offering or subsequent sale occurs, the Company will consider the pricing indicated by the external event to corroborate the private valuation. For debt investments, the Company may employ the Market Based Approach (as described below) to assess the total enterprise value of the portfolio company, in order to evaluate the enterprise value coverage of the Company's debt investment. For equity investments or in cases where the Market Based Approach implies a lack of enterprise value coverage for the debt investment, the Company may additionally employ a discounted cash flow analysis based on the free cash flows of the portfolio company to assess the total enterprise value. After enterprise value coverage is demonstrated for the Company's debt investments through the method(s) above, the Income Based Approach (as described below) may be employed to estimate the fair value of the investment. Market Based Approach: The Company may estimate the total enterprise value of each portfolio company by utilizing EBITDA or revenue multiples of publicly traded comparable companies and comparable transactions. The Company considers numerous factors when selecting the appropriate companies whose trading multiples are used to value its portfolio companies. These factors include, but are not limited to, the type of organization, similarity to the business being valued, and relevant risk factors, as well as size, profitability and growth expectations. The Company may apply an average of various relevant comparable company EBITDA or revenue multiples to the portfolio company's latest twelve month ("LTM") EBITDA or revenue or projected EBITDA or revenue to calculate the enterprise value of the portfolio company. Significant increases or decreases in the EBITDA or revenue multiples will result in an increase or decrease in enterprise value, which may result in an increase or decrease in the fair value estimate of the investment. In applying the market based approach as of March 31, 2023 and December 31, 2022, the Company used the relevant EBITDA or revenue multiple ranges set forth in the table below to determine the enterprise value of its portfolio companies. The Company believes these were reasonable ranges in light of current comparable company trading levels and the specific portfolio companies involved. Income Based Approach: The Company also may use a discounted cash flow analysis to estimate the fair value of the investment. Projected cash flows represent the relevant security's contractual interest, fee and principal payments plus the assumption of full principal recovery at the investment's expected maturity date. These cash flows are discounted at a rate established utilizing a combination of a yield calibration approach and a comparable investment approach. The yield calibration approach incorporates changes in the credit quality (as measured by relevant statistics) of the portfolio company, as compared to changes in the yield associated with comparable credit quality market indices, between the date of origination and the valuation date. The comparable investment approach utilizes an average yield-to-maturity of a selected set of high-quality, liquid investments to determine a comparable investment discount rate. Significant increases or decreases in the discount rate would result in a decrease or increase in the fair value measurement. In applying the income based approach as of March 31, 2023 and December 31, 2022, the Company used the discount ranges set forth in the table below to value investments in its portfolio companies. The unobservable inputs used in the fair value measurement of the Company's Level III investments as of March 31, 2023 were as follows: Range Type Fair Value as of March 31, 2023 Approach Unobservable Input Low High Weighted First lien $ 136,059 Market & income approach EBITDA multiple 8.0x 37.8x 17.4x Revenue multiple 4.5x 16.6x 9.2x Discount rate 8.0 % 12.9 % 10.4 % 1,930 Market quote Broker quote N/A N/A N/A 11,632 Other N/A (2) N/A N/A N/A Second lien 8,268 Market & income approach EBITDA multiple 14.0x 18.0x 16.0x Market & income approach Discount rate 10.7 % 12.2 % 11.9 % Subordinated 3,040 Market & income approach EBITDA multiple 19.0x 24.5x 21.8x Discount rate 13.1 % 14.4 % 13.8 % Equity and other 827 Market & income approach Revenue multiple 4.5x 5.5x 5.0x Discount rate 14.4 % 15.3 % 14.9 % $ 161,756 (1) Unobservable inputs were weighted by the relative fair value of the investments. (2) Fair value was determined based on transaction pricing or recent acquisition or sale as the best measure of fair value with no material changes in operations of the related portfolio company since the transaction date. The unobservable inputs used in the fair value measurement of the Company's Level III investments as of December 31, 2022 were as follows: Range Type Fair Value as of December 31, 2022 Approach Unobservable Input Low High Weighted First lien $ 82,517 Market & income approach EBITDA multiple 10.0x 38.0x 19.8x Revenue multiple 8.0x 17.0x 10.4x Discount rate 8.8 % 12.5 % 10.5 % 10,831 Other N/A (2) N/A N/A N/A Second lien 7,239 Market & income approach EBITDA multiple 14.0x 18.0x 16.0x Discount rate 11.2 % 12.6 % 12.3 % Subordinated 3,077 Market & income approach EBITDA multiple 23.5x 23.5x 23.5x Discount rate 14.8 % 14.8 % 14.8 % Equity and other 763 Market & income approach EBITDA multiple 25.0x 25.0x 25.0x Discount rate 14.9 % 14.9 % 14.9 % $ 104,427 (1) Unobservable inputs were weighted by the relative fair value of the investments. (2) Fair value was determined based on transaction pricing or recent acquisition or sale as the best measure of fair value with no material changes in operations of the related portfolio company since the transaction date. The BMO Subscription Line (as defined below) and the UBS Credit Facility (as defined below) are considered Level III investments. See Note 6. Borrowings for details. The following are the principal amount and fair value of the Company’s borrowings as of March 31, 2023. Fair value is estimated by discounting remaining payments using applicable current market rates, which take into account changes in the Company’s marketplace credit ratings, or market quotes, if available. As of March 31, 2023 December 31, 2022 Principal Amount Fair Value Principal Amount Fair Value BMO Subscription Line $ 45,000 $ 45,013 $ 53,700 53,674 UBS Credit Facility 58,400 59,046 N/A N/A Total $ 103,400 $ 104,059 $ 53,700 $ 53,674 N/A Not applicable.

Agreements and Related Parties

Agreements and Related Parties	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
Agreements and Related Parties	Agreements and Related PartiesThe Company entered into an investment advisory and management agreement (the "Investment Management Agreement") with the Investment Adviser on May 3, 2022. The Investment Management Agreement initially had a term of two years which began on May 3, 2022, and thereafter shall continue automatically for successive annual periods, provided that such continuance is specifically approved at least annually by (A) the vote of the board of directors, or by the vote of a majority of the outstanding voting securities of the Company and (B) the vote of a majority of the Company's directors who are not parties to the Investment Management Agreement or "interested persons" (as such term is defined in Section 2(a)(19) of the 1940 Act) of any such party, in accordance with the requirements of the 1940 Act. Under the Investment Management Agreement, the Investment Adviser manages the day-to-day operations of, and provides investment advisory services, to the Company. For providing these services, the Investment Adviser receives an annual base management fee and incentive fee from the Company. Although the initial two year term of the Investment Management Agreement would not have expired until May 3, 2024, the Company's board of directors most recently re-approved the Investment Management Agreement on January 24, 2023, at an in-person meeting, for a period of 12 months commencing on March 1, 2023. Pursuant to the Investment Management Agreement, the base management fee is payable quarterly in arrears at an annual rate of 1.15% of the aggregate contributed capital from all unitholders (including any outstanding borrowings under any subscription line drawn in lieu of capital calls) less any return of capital distributions and less any cumulative realized losses since inception (calculated net of any subsequently reversed realized losses and net of any realized gains) as of the last day of the applicable quarter. For the period from the effective date of the Investment Management Agreement through the one year anniversary of the Initial Drawdown Date (as defined in the Investment Management Agreement), the base management fee shall be reduced by 50% (for the avoidance of doubt, this results in a management fee rate of 0.575% through May 9, 2023, the one year anniversary of the Initial Drawdown Date). Because the one year anniversary of the Initial Drawdown Date occurs on a date other than the last day of a calendar quarter, the management fee shall be prorated for such calendar quarter and calculated based on the number of days in such period up to, and including, the one year anniversary of the Initial Drawdown Date. The base management fee could be reduced by any voluntary fee waivers made by the Investment Adviser. The management fee will be reduced, but not below zero, by any amounts paid by the Company or its subsidiaries to a placement agent, any organizational and offering expenses in excess of the lesser $2,500 or 0.50% of the aggregate Capital Commitments and any fund expenses in excess of the Specified Expenses Cap (as defined below). The Investment Adviser has entered into agreements with placement agents that provide for ongoing payments from the Investment Adviser based upon the amount of a unitholder's Capital Commitment or capital contributions. Neither the Company nor any unitholders will bear any of the fees paid to placement agents of the Company as any such fees paid by the Company will offset the management fees. The incentive fee will consist of two components that are independent of each other, with the result that one component may be payable even if the other is not. A portion of the incentive fee is based on a percentage of the Company's income and a portion is based on a percentage of the Company's capital gains, each as described below. Incentive Fee on Pre-Incentive Fee Net Investment Income The portion based on the Company's income (the "Income Incentive Fee") is based on pre-incentive fee net investment income ("Pre-Incentive Fee Net Investment Income"). Pre-Incentive Fee Net Investment Income means interest income, dividend income and any fee income (including any other fees (other than fees for providing managerial assistance), such as commitment, origination, structuring, upfront, diligence and consulting fees or other fees that the Company receives from portfolio companies) accrued during the calendar quarter, minus the Company's operating expenses for the quarter (including the management fee, expenses payable under the Administration Agreement, and any interest expense and distributions paid on any issued and outstanding preferred units, but excluding the incentive fee). Pre-Incentive Fee Net Investment Income includes, in the case of investments with a deferred interest feature (such as original issue discount, debt instruments with PIK interest and zero coupon securities), accrued income that we have not yet received in cash. Pre-Incentive Fee Net Investment Income does not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation. Pre-Incentive Fee Net Investment Income, expressed as a rate of return on the value of the Company's members' capital at the end of the immediate preceding quarter, is compared to a "hurdle rate" of return of 1.75% per quarter (7.0% annualized). The Company will pay the Investment Adviser an incentive fee quarterly in arrears with respect to the Company's Pre-Incentive Fee Net Investment Income in each calendar quarter as follows: • no incentive fee based on Pre-Incentive Fee Net Investment Income in any calendar quarter in which the Company's Pre-Incentive Fee Net Investment Income does not exceed the hurdle rate of 1.75%; • 100% of the dollar amount of our Pre-Incentive Fee Net Investment Income with respect to that portion of such Pre-Incentive Fee Net Investment Income, if any, that exceeds the hurdle rate but is less than or equal to a rate of return of 2.059% (8.235% annualized). The Company refers to this portion of the Company's Pre-Incentive Fee Net Investment Income (which exceeds the hurdle rate but is less than 2.059%) as the "catch-up." The "catch-up" is meant to provide the Investment Adviser with approximately 15.0% of the Company's Pre-Incentive Fee Net Investment Income as if a hurdle rate did not apply if this net investment income exceeds 2.059% in any calendar quarter; and • 15.0% of the dollar amount of the Company's Pre-Incentive Fee Net Investment Income, if any, that exceeds a rate of return of 2.059% (8.235% annualized). This reflects that once the hurdle rate is reached and the catch-up is achieved, 15.0% of all Pre-Incentive Fee Net Investment Income thereafter is allocated to the Investment Adviser. For the three months ended March 31, 2023, there were no incentive fees waived. The fees that are payable under the Investment Management Agreement for any partial period will be appropriately prorated. Incentive Fee on Capital Gains The second component of the incentive fee is the capital gains incentive fee. The Company will pay the Investment Adviser an incentive fee with respect to the Company's cumulative realized capital gains computed net of all realized capital losses and unrealized capital depreciation since inception ("Cumulative Net Realized Gains") based on the waterfall below: a. First, no incentive fee is payable to the Investment Adviser on Cumulative Net Realized Gains until total return of capital distributions, distributions of net investment income and distributions of net realized capital gains to unitholders is equal to total capital contributions; b. Second, no incentive is payable to the Investment Adviser on Cumulative Net Realized Gains until the Company has paid cumulative distributions equal to an annualized, cumulative internal rate of return of 7.0% on the total contributed capital to the Company calculated from the date that each such amount was due to be contributed to the Company until the date each such distribution is paid; c. Third, upon a distribution that results in cumulative distributions exceeding the amounts in clause (a) and (b) above, an incentive fee on capital gains payable to the Investment Adviser equal to 100.0% of the amount of Cumulative Net Realized Gains until the Investment Adviser has received (together with amounts the Investment Adviser has received under Income Incentive Fees) an amount equal to 15.0% of the sum of (i) the cumulative distributions to unitholders made pursuant to clause (b) above, (ii) Income Incentive Fee paid to the Investment Adviser and (iii) amounts paid to the Investment Adviser pursuant to this clause (c); and d. Thereafter, an incentive fee on capital gains equal to 15.0% of additional undistributed Cumulative Net Realized Gains. Upon termination of the Company, the Investment Adviser will be required to return incentive fees to the Company to the extent that: (i) the Investment Adviser has received cumulative incentive fees in excess of 15.0% of the sum of (A) the Company's cumulative distributions other than return of capital contributions and (B) the cumulative incentive fees paid to the Investment Adviser; or (ii) the unitholders have not received a 7.0% cumulative internal rate of return; provided that in no event will such restoration be more than the incentive fees received by the Investment Adviser. In accordance with GAAP, the Company accrues a hypothetical capital gains incentive fee based upon the cumulative net realized capital gains and realized capital losses and the cumulative net unrealized capital appreciation and unrealized capital depreciation on investments held at the end of each period. Actual amounts paid to the Investment Adviser are consistent with the Investment Management Agreement and are based only on realized capital gains computed net of all realized capital losses and unrealized capital depreciation on a cumulative basis from inception through the end of each calendar year as if the entire portfolio was sold at fair value. Expense Limitation Notwithstanding the foregoing, the Investment Adviser has agreed to reduce and/or waive its management fee (the "Specified Expenses Cap") each year such that the Company will not be required to pay Specified Expenses (as defined below) in excess of a maximum aggregate amount in any calendar year (prorated for partial years and portions of years for which each applicable prong of the cap applies) equal to: (1) during the Closing Period, 0.40% of the greater of (A) $750,000 and (B) actual aggregate Capital Commitments as of the end of such calendar year, (2) at the end of the Closing Period until the end of the Investment Period, 0.40% of aggregate committed capital and (3) after the end of the Investment Period, 0.40% of the Company's average Members' Capital for the calendar year. Further, if the actual aggregate committed capital of the Company at the end of the Closing Period is less than $750,000, the prong of the Specified Expenses Cap in clause (1) above will be retroactively adjusted to equal 0.40% of aggregate committed capital at the end of the Closing Period, and the Investment Adviser has agreed to further reduce and/or waive its management fee for the year in which the Closing Period ends in an amount equal to the difference between (A) the amount that would have been required to be waived/reimbursed pursuant to clause (1) above as adjusted and (B) the amount previously waived/reimbursed pursuant to clause (1) above. "Specified Expenses" of the Company means all Company Expenses (as defined under "Fund Expenses" in the limited liability company agreement, as amended and restated on June 10, 2022, the "Second A&R LLC Agreement") incurred in the operation of the Company with the exception of: (i) the management fee, (ii) any incentive fees, (iii) Organizational and Offering Expenses (as defined in the Second A&R LLC Agreement) (which are subject to Organizational and Offering Expense Cap), (iv) Placement Fees (as defined in the Second A&R LLC Agreement), (v) interest on and fees and expenses arising out of all Company indebtedness and other financing, (vi) costs of any litigation and damages (including the costs of any indemnity or contribution right granted to any placement agent or third-party finder engaged by the Company or its affiliates) and (vii) for the avoidance of doubt, if applicable, any investor level withholding or other taxes. If, while the Investment Adviser is the investment adviser to the Company, the annualized Specified Expenses for a given calendar year are less than the Specified Expenses Cap, the Investment Adviser shall be entitled to reimbursement by the Company of the compensation waived and other expenses borne by the Investment Adviser (the "Reimbursement Amount") on behalf of the Company pursuant to the expense limitation and reimbursement agreement between the Company and the Investment Adviser (the "Expense Limitation and Reimbursement Agreement") during any of the previous thirty-six months, and provided that such amount paid to the Investment Adviser will in no event exceed the total Reimbursement Amount and will not include any amounts previously reimbursed. The Reimbursement Amount plus the annualized Specified Expenses for a given calendar year shall not exceed the Specified Expenses Cap. The Investment Adviser may recapture a Specified Expense in any year within the thirty-six month period after the Investment Adviser bears the expense. For the three months ended March 31, 2023, there have been no reimbursements from the Investment Adviser pursuant to this provision. The Expense Limitation and Reimbursement Agreement may be amended by mutual agreement of the parties, provided that any amendment that could result in an increase in expenses borne by the Company also must be approved by vote of a majority of the outstanding Units. The following table summarizes the management fees and incentive fees incurred by the Company for the three months ended March 31, 2023. Three Months Ended March 31, 2023 Management fee $ 372 Less: management fee waiver (186) Net management fee 186 Incentive fee, excluding accrued incentive fees on capital gains $ 369 For the three months ended March 31, 2023, no incentive fee on capital gains was accrued or owed under the Investment Management Agreement by the Company, as cumulative net realized capital gains did not exceed cumulative unrealized capital depreciation. The Company has entered into an administration agreement with the Administrator (the "Administration Agreement") under which the Administrator provides administrative services. The Administrator maintains, or oversees the maintenance of, the Company's consolidated financial records, prepares reports filed with the U.S. Securities and Exchange Commission (the "SEC"), generally monitors the payment of the Company's expenses and oversees the performance of administrative and professional services rendered by others. The Administrator has hired a third-party sub-administrator to assist with the provision of administrative services. The Company reimburses the Administrator for the Company's allocable portion of overhead and other expenses incurred by the Administrator in performing its obligations to the Company under the Administration Agreement, including compensation of the Company's chief financial officer and chief compliance officer, and their respective staffs. Pursuant to the Administration Agreement and further restricted by the Company, the Administrator may, in its own discretion, submit to the Company for reimbursement some or all of the expenses that the Administrator has incurred on behalf of the Company during any quarterly period. As a result, the amount of expenses for which the Company will have to reimburse the Administrator may fluctuate in future quarterly periods and there can be no assurance given as to when, or if, the Administrator may determine to limit the expenses that the Administrator submits to the Company for reimbursement in the future. The Administrator cannot recoup any expenses that the Administrator has previously waived. For the three months ended March 31, 2023, approximately $146 of indirect administrative expenses were included in administrative expenses, none of which were waived by the Administrator. As of March 31, 2023 and December 31, 2022, approximately $146 and $204, respectively, of indirect administrative expenses were included in payable to affiliates. The Company, the Investment Adviser and the Administrator have also entered into a Trademark License Agreement, as amended (the "Trademark License Agreement"), with New Mountain Capital, pursuant to which New Mountain Capital has agreed to grant the Company, the Investment Adviser and the Administrator a non-exclusive, royalty-free license to use the "New Mountain Capital" name. Under the Trademark License Agreement, as amended, subject to certain conditions, the Company, the Investment Adviser and the Administrator will have a right to use the "New Mountain Capital" name, for so long as the Investment Adviser or one of its affiliates remains the investment adviser of the Company. Other than with respect to this limited license, the Company, the Investment Adviser and the Administrator will have no legal right to the "New Mountain Capital" name. The Investment Adviser and its affiliates may also manage other funds in the future that may have investment mandates that are similar, in whole or in part, to the Company's investment mandates. The Investment Adviser and its affiliates may determine that an investment is appropriate for the Company or for one or more of those other funds. In such event, depending on the availability of such investment and other appropriate factors, the Investment Adviser or its affiliates may determine that the Company should invest side-by-side with one or more other funds. Any such investments will be made only to the extent permitted by applicable law and interpretive positions of the SEC and its staff and consistent with the Investment Adviser's allocation procedures. On October 8, 2019, the SEC issued an exemptive order (the "Exemptive Order") to the Investment Adviser and certain of its affiliates, which superseded a prior order issued on December 18, 2017, which permits the Company to co-invest in portfolio companies with certain funds or entities managed by the Investment Adviser or its affiliates in certain negotiated transactions where co-investing would otherwise be prohibited under the 1940 Act, subject to the conditions of the Exemptive Order. Pursuant to the Exemptive Order, the Company is permitted to co-invest with its affiliates if a "required majority" (as defined in Section 57(o) of the 1940 Act) of the Company's directors who are not "interested persons," as that term is defined in Section 2(a)(19) of the 1940 Act (the "Independent Directors"), make certain conclusions in connection with a co-investment transaction, including, but not limited to, that (1) the terms of the potential co-investment transaction, including the consideration to be paid, are reasonable and fair to the Company and its unitholders and do not involve overreaching in respect of the Company or its unitholders on the part of any person concerned, and (2) the potential co-investment transaction is consistent with the interests of the Company's unitholders and is consistent with its then-current investment objective and strategies. In addition, pursuant to an exemptive order issued by the SEC on April 8, 2020 and applicable to all BDCs through December 31, 2020 (the "Temporary Relief"), the Company was permitted, subject to the satisfaction of certain conditions, to complete follow-on investments in our existing portfolio companies with certain affiliates that are private funds if such private funds did not previously hold an investment in such existing portfolio company. Without the Temporary Relief, such private funds would not be able to participate in such follow-on investments with the Company unless the private funds had previously acquired securities of the portfolio company in a co-investment transaction with the Company. Although the Temporary Relief expired on December 31, 2020, the SEC’s Division of Investment Management had indicated that until March 31, 2022, it would not recommend enforcement action, to the extent that any BDC with an existing co-investment order continued to engage in certain transactions described in the Temporary Relief, pursuant to the same terms and conditions described therein. The Temporary Relief is no longer effective; however, the Company filed an application to amend its existing Exemptive Order (as defined below) on May 24, 2022, as amended on June 22, 2022. On August 30, 2022, New Mountain Finance Corporation and certain of its affiliates, including the Company, received an Order from the SEC which amended its existing Exemptive Order to permit the Company to continue to complete follow-on investments in its existing portfolio companies with certain affiliates that are private funds if such private funds do not hold an investment in such existing portfolio company, subject to certain conditions.

Borrowings

Borrowings	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Borrowings	Borrowings BMO Subscription Line —On May 9, 2022, the Company entered into a Loan Authorization Agreement with BMO Harris Bank N.A. ("BMO") (as amended, from time to time, and most recently amended on October 27, 2022, the "Loan Authorization Agreement"), which allows the Company to borrow on a revolving credit basis an aggregate principal amount which cannot exceed $96,000 (the "BMO Subscription Line"). All outstanding borrowings under the BMO Subscription Line are due on BMO's demand within 15 business days or on the date 6 months after each advance date, which varies throughout the period. The BMO Subscription Line is collateralized by the unfunded Capital Commitments of each of the Company's unitholders. All fees associated with the origination and amendment of the BMO Subscription Line are capitalized on the Consolidated Statements of Assets, Liabilities and Members' Capital and amortized and charged against income as other financing costs over the life of the BMO Subscription Line. The BMO Subscription Line bears interest at the greater of the prime commercial rate minus 0.25% per annum or the Secured Overnight Financing Rate ("SOFR") Quoted Rate (as defined below) for such day plus 2.50% per annum. SOFR Quoted Rate means as of any day of determination, 3-month Term SOFR on the date that is two U.S. Government Securities Business Days prior to such day of determination as such rate is published by the Term SOFR Administrator plus a credit spread adjustment of 0.15%. For the three months ended March 31, 2023, interest expense and amortization of financing costs incurred on the BMO Subscription Line were $1,205 and $4, respectively. The weighted average interest rate and effective interest rate on the BMO Subscription Line for the three months ended March 31, 2023 were 7.5% and 7.5%, respectively. As of March 31, 2023 and December 31, 2022, the outstanding balance on the BMO Subscription Line was $45,000 and $53,700, respectively, and the Company was in compliance with the applicable covenants in the BMO Subscription Line on such dates. UBS Credit Facility —On January 25, 2023, the Company's wholly-owned subsidiary, GIV SPV, entered into the Loan and Security Agreement (the "Loan and Security Agreement") as the borrower, the Company as collateral manager and equityholder, the lenders from time to time party thereto, UBS AG London Branch ("UBS"), as the administrative agent, U.S. Bank Trust Company, National Association as the collateral agent, and U.S. Bank National Association as the document custodian, which is structured as a secured revolving credit facility (the "UBS Credit Facility"). The UBS Credit Facility will mature on January 25, 2028 and has a maximum facility amount of $250,000. Under the UBS Credit Facility, GIV SPV is permitted to borrow up to 30.0%, 40.0%, 50.0%, 65.0%, 70.0% or 75.0% of the purchase price of pledged assets, subject to approval by UBS. The UBS Credit Facility is non-recourse to the Company and is collateralized by all of the investments of GIV SPV on an investment by investment basis. All fees associated with the origination, amending or upsizing of the UBS Credit Facility are capitalized on the Company's Consolidated Statements of Assets, Liabilities and Members' Capital and charged against income as other financing expenses over the life of the UBS Credit Facility. The UBS Credit Facility contains certain customary affirmative and negative covenants and events of default. The covenants are generally not tied to mark to market fluctuations in the prices of GIV SPV investments, but rather to the performance of the underlying portfolio companies. The UBS Credit Facility bears interest at a rate of Term SOFR plus 2.85% per annum. The UBS Credit Facility also charges a non-usage fee, based on the unused facility amount multiplied by the Non-Usage Fee Rate (as defined in the Loan and Security Agreement). In connection with ramping the portfolio, the Company is in the process of amending the UBS Credit Facility in order to achieve more favorable terms, specifically relating to minimum utilization. In anticipation of this amendment, the Company has reclassed certain interest expense to prepaid interest in Other Assets on the Consolidated Statements of Assets, Liabilities and Members' Capital. For the three months ended March 31, 2023, interest expense, non-usage fee and amortization of financing costs incurred on the UBS Credit Facility were $459, $196 and $59, respectively. The weighted average interest rate and effective interest rate on the UBS Credit Facility for the three months ended March 31, 2023 were 7.5% and 22.9%, respectively. As of March 31, 2023, the outstanding balance on the UBS Credit Facility was $58,400, and the Company was in compliance with the applicable covenants in the UBS Credit Facility on such date.

Regulation

Regulation	3 Months Ended
	Mar. 31, 2023
Investment Company [Abstract]
Regulation	RegulationThe Company intends to elect to be treated for U.S. federal income tax purposes as a RIC under Subchapter M of the Code with the filing of its tax return for the year ending December 31, 2022, and thereafter intends to comply with the requirements to continue to qualify and maintain its status as a RIC annually. In order to continue to qualify and be subject to tax treatment as a RIC for U.S. federal income tax purposes, among other things, the Company is generally required to timely distribute to its unitholders at least 90.0% of its investment company taxable income, as defined by the Code, for each year. The Company, among other things, intends to make and will continue to make the requisite timely distributions to its unitholders, and as such, the Company will generally be relieved from U.S. federal, state, and local income taxes (excluding excise taxes which may be imposed under the Code). Additionally, as a BDC, the Company must not acquire any assets other than "qualifying assets" as defined in Section 55(a) of the 1940 Act unless, at the time the acquisition is made, at least 70.0% of its total assets are qualifying assets (with certain limited exceptions). In addition, the Company must offer to make available to all "eligible portfolio companies" (as defined in the 1940 Act) significant managerial assistance.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesIn the normal course of business, the Company may enter into contracts that contain a variety of representations and warranties and which provide general indemnifications. The Company may also enter into future funding commitments such as revolving credit facilities, bridge financing commitments or delayed draw commitments. As of March 31, 2023, the Company had unfunded commitments on revolving credit facilities of $9,948, no outstanding bridge financing commitments, and other future funding commitments of $29,539. As of December 31, 2022, the Company had unfunded commitments on revolving credit facilities of $5,939, no outstanding bridge financing commitments, and other future funding commitments of $30,263. The unfunded commitments on revolving credit facilities and delayed draws are disclosed on the Company's Consolidated Schedules of Investments. The Company also has revolving borrowings available under the BMO Subscription Line and the UBS Credit Facility as of March 31, 2023 and had revolving borrowings available under the BMO Subscription Line as of December 31, 2022. See Note 6. Borrowings , for details. The Company may from time to time enter into financing commitment letters. As of March 31, 2023 and December 31, 2022, the Company had commitment letters to purchase investments in the aggregate par amount of $0 and $33,881, respectively, which could require funding in the future.

Members' Capital

Members' Capital	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Members' Capital	Members' Capital The following table summarizes the total Units issued and proceeds received related to capital drawdowns delivered pursuant to the Subscription Agreements for the three months ended March 31, 2023. Drawdown Date Unit Issue Date Units Issued Aggregate Offering Price February 23, 2023 March 9, 2023 982,500 $ 9,825 The following table reflects the distributions declared on the Company's common units for the three months ended March 31, 2023. Date Declared Record Date Payment Date Per Unit Amount March 2, 2023 March 8, 2023 April 20, 2023 $ 0.175 March 30, 2023 March 31, 2023 April 20, 2023 0.150 $ 0.325

Earnings (Loss) Per Unit

Earnings (Loss) Per Unit	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Earnings (Loss) Per Unit	Earnings (Loss) Per Unit The following information sets forth the computation of basic net decrease in the Company's members' capital per unit resulting from operations for the three months ended March 31, 2023: Three Months Ended March 31, 2023 Earnings (Loss) per unit—basic & diluted Numerator for basic & diluted earnings per unit: $ 3,383 Denominator for basic & diluted weighted average unit: 7,776,914 Basic & diluted earnings per unit: $ 0.43

Financial Highlights

Financial Highlights	3 Months Ended
	Mar. 31, 2023
Investment Company [Abstract]
Financial Highlights	Financial Highlights The following information sets forth the Company's financial highlights for the three months ended March 31, 2023. Three Months Ended March 31, 2023 Per unit data(1): Members' capital, December 31, 2022 $ 9.77 Net investment income 0.27 Net realized and unrealized gains(2) 0.18 Total net increase 0.45 Distributions declared to unitholders from net investment income (0.33) Members' capital, March 31, 2023 $ 9.89 Total return based on members' capital(3) 4.63 % Units outstanding at end of period 8,508,331 Average weighted units outstanding for the period 7,776,914 Average members' capital for the period $ 76,036 Ratio to average members' capital: Net investment income(4) 11.97 % Total expenses, before waivers/reimbursements(4) 17.13 % Total expenses, net of waivers/reimbursements(4) 16.13 % Average debt outstanding—BMO Subscription Line $ 65,306 Average debt outstanding—UBS Credit Facility $ 17,106 Asset coverage ratio 181.36 % Portfolio turnover 0.22 % Capital Commitments $ 282,100 Funded Capital Commitments $ 84,630 % of Capital Commitments funded 30.00 % (1) Per unit data is based on weighted average units outstanding for the respective period (except for distributions declared to unitholders, which are based on actual rate per unit). (2) The total amount shown may not correspond with the aggregate amount for the period as it includes the effect of the timing of capital transactions which for the three months ended March 31, 2023 was $0.02. (3) Total return is calculated assuming an initial purchase price of $10.00 per Unit and a sale at members' capital per Unit on the last day of the period. Dividends and distributions, if any, are assumed for purposes of this calculation, to be reinvested at members' capital per Unit on the last day of the respective quarter. Total return calculation is not annualized. (4) Annualized, except organizational and offering costs.

Recent Accounting Standards Upd

Recent Accounting Standards Updates	3 Months Ended
	Mar. 31, 2023
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standards Updates	Recent Accounting Standards Updates In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update No. 2020-04, Reference Rate Reform (Topic 848) : Facilitation of the Effects of Reference Rate Reform on Financial Reporting ("ASU 2020-04"). The amendments in ASU 2020-04 provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The standard is effective as of March 12, 2020 through December 31, 2022. Management is currently evaluating the impact of the optional guidance on the Company's consolidated financial statements and disclosures. The Company did not utilize the optional expedients and exceptions provided by ASU 2020-04 during the period from May 9, 2022 (commencement of operations) to March 31, 2023. In December 2022, the FASB issued ASU No. 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848, which deferred the sunset day of this guidance to December 31, 2024. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsThe Company has evaluated the need for disclosures and/or adjustments resulting from recent developments through the date the financial statements were issued. There have been no recent developments that require recognition or disclosure in these consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of accounting	Basis of accounting —The Company's consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States ("GAAP"). The Company is an investment company following accounting and reporting guidance in Accounting Standards Codification Topic 946, Financial Services — Investment Companies ("ASC 946"). The Company consolidates its wholly-owned direct subsidiaries GIV SPV and GIV Issuer SPV. The Company's consolidated financial statements reflect all adjustments and reclassifications which, in the opinion of management, are necessary for the fair presentation of the results of operations and financial condition for the period(s) presented. All intercompany transactions have been eliminated. Revenues are recognized when earned and expenses when incurred. The financial results of the Company's portfolio investments are not consolidated in the financial statements. The Company's interim consolidated financial statements are prepared in accordance with GAAP and pursuant to the requirements for reporting on Form 10-Q and Article 6 and 10 of Regulation S-X. Accordingly, the Company’s interim consolidated financial statements do not include all of the information and notes required by GAAP for annual financial statements. In the opinion of management, all adjustments, consisting solely of normal recurring accruals considered necessary for the fair presentation of financial statements for the interim period, have been included. The current period's results of operations will not necessarily be indicative of results that ultimately may be achieved for the fiscal year ending December 31, 2023.
Investments	Investments —The Company applies fair value accounting in accordance with GAAP. Fair value is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Investments are reflected on the Company's Consolidated Statements of Assets, Liabilities and Members' Capital at fair value, with changes in unrealized gains and losses resulting from changes in fair value reflected in the Company's Consolidated Statement of Operations as "Net change in unrealized appreciation (depreciation) of investments" and realizations on portfolio investments reflected in the Company's Consolidated Statement of Operations as "Net realized gains (losses) on investments". The Company values its assets on a quarterly basis, or more frequently if required under the 1940 Act. In all cases, the Company's board of directors is ultimately and solely responsible for determining the fair value of the Company's portfolio investments on a quarterly basis in good faith, including investments that are not publicly traded, those whose market prices are not readily available and any other situation where its portfolio investments require a fair value determination. Security transactions are accounted for on a trade date basis. The Company's quarterly valuation procedures are set forth in more detail below: (1) Investments for which market quotations are readily available on an exchange are valued at such market quotations based on the closing price indicated from independent pricing services. (2) Investments for which indicative prices are obtained from various pricing services and/or brokers or dealers are valued through a multi-step valuation process, as described below, to determine whether the quote(s) obtained is representative of fair value in accordance with GAAP. a. Bond quotes are obtained through independent pricing services. Internal reviews are performed by the investment professionals of the Investment Adviser to ensure that the quote obtained is representative of fair value in accordance with GAAP and, if so, the quote is used. If the Investment Adviser is unable to sufficiently validate the quote(s) internally and if the investment's par value or its fair value exceeds the materiality threshold, the investment is valued similarly to those assets with no readily available quotes (see (3) below); and b. For investments other than bonds, the Company looks at the number of quotes readily available and performs the following procedures: i. Investments for which two or more quotes are received from a pricing service are valued using the mean of the mean of the bid and ask of the quotes obtained. The Company will evaluate the reasonableness of the quote, and if the quote is determined to not be representative of fair value, the Company will use one or more of the methodologies outlined below to determine fair value; and ii. Investments for which one quote is received from a pricing service are validated internally. The investment professionals of the Investment Adviser analyze the market quotes obtained using an array of valuation methods (further described below) to validate the fair value. If the Investment Adviser is unable to sufficiently validate the quote internally and if the investment's par value or its fair value exceeds the materiality threshold, the investment is valued similarly to those assets with no readily available quotes (see (3) below). (3) Investments for which quotations are not readily available through exchanges, pricing services, brokers, or dealers are valued through a multi-step valuation process: a. Each portfolio company or investment is initially valued by the investment professionals of the Investment Adviser responsible for the credit monitoring; b. Preliminary valuation conclusions will then be documented and discussed with the Company's senior management; c. If an investment falls into (3) above for four consecutive quarters and if the investment's par value or its fair value exceeds the materiality threshold, then at least once each fiscal year, the valuation for each portfolio investment for which the Company does not have a readily available market quotation will be reviewed by an independent valuation firm engaged by the Company's board of directors; and d. When deemed appropriate by the Company's management, an independent valuation firm may be engaged to review and value investment(s) of a portfolio company, without any preliminary valuation being performed by the Investment Adviser. The investment professionals of the Investment Adviser will review and validate the value provided. For investments in revolving credit facilities and delayed draw commitments, the cost basis of the funded investments purchased is offset by any costs/netbacks received for any unfunded portion on the total balance committed. The fair value is also adjusted for the price appreciation or depreciation on the unfunded portion. As a result, the purchase of a commitment not completely funded may result in a negative fair value until it is called and funded.
Cash and cash equivalents	Cash and cash equivalents—Cash and cash equivalents include cash and short-term, highly liquid investments. The Company defines cash equivalents as securities that are readily convertible into known amounts of cash and so near maturity that there is insignificant risk of changes in value. These securities have original maturities of three months or less.
Revenue recognition	Revenue recognition Sales and paydowns of investments: Realized gains and losses on investments are determined on the specific identification method. Interest and dividend income: Interest income, including amortization of premium and discount using the effective interest method, is recorded on the accrual basis and periodically assessed for collectability. Interest income also includes interest earned from cash on hand. Upon the prepayment of a loan or debt security, any prepayment penalties are recorded as part of interest income. The Company has loans and certain preferred equity investments in its portfolio that contain a payment-in-kind ("PIK") interest or dividend provision. PIK interest and dividends are accrued and recorded as income at the contractual rates, if deemed collectible. The PIK interest and dividends are added to the principal or share balances on the capitalization dates and are generally due at maturity or when redeemed by the issuer. For the three months ended March 31, 2023, the Company recognized PIK dividends from investments of $25 and PIK interest from investments of $93. Dividend income on preferred securities is recorded as dividend income on an accrual basis to the extent that such amounts are deemed collectible. Non-accrual income: Investments are placed on non-accrual status when principal or interest payments are past due for 30 days or more and when there is reasonable doubt that principal or interest will be collected. Accrued cash and un-capitalized PIK interest or dividends are reversed when an investment is placed on non-accrual status. Previously capitalized PIK interest or dividends are not reversed when an investment is placed on non-accrual status. Interest or dividend payments received on non-accrual investments may be recognized as income or applied to principal depending upon management's judgment of the ultimate collectability. Non-accrual investments are restored to accrual status when past due principal and interest is paid and, in management's judgment, are likely to remain current. As of March 31, 2023 and December 31, 2022, no investments were on non-accrual status. Fee income: Fee income represents delayed compensation, revolver fees, amendment fees, assignment fees, upfront fees and other miscellaneous fees received and are typically non-recurring in nature. Delayed compensation is income earned
Interest and other financing expenses	Interest and other financing expenses—Interest and other financing fees are recorded on an accrual basis by the Company.
Organizational expenses	Organizational expenses—Organizational expenses include costs and expenses incurred in connection with the formation and organization of the Company and are expensed as incurred in the Consolidated Statement of Operations. Any organizational and offering expenses paid by the Company in excess of the lesser of $2,500 or 0.50% of the aggregate Capital Commitments will be applied as a reduction to the base management fee paid to the Investment Adviser and cannot be recouped by the Investment Adviser.
Deferred offering costs	Deferred offering costs—The Company's deferred offering costs consists of fees and expenses incurred in connection with the offering of the Company's Units. Upon the issuance of Units, deferred offering costs are then amortized into Organizational and Offering Expenses on the Consolidated Statement of Operations on a straight line basis over a period of 12 months beginning on the date of commencement of operations. Deferred offering costs are included on the Company’s Consolidated Statements of Assets, Liabilities and Members' Capital until amortized.
Deferred financing costs	Deferred financing costs—The deferred financing costs of the Company consist of capitalized expenses related to the origination and amending of the Company's borrowings. The Company amortizes these costs into expense over the stated life of the related borrowing.
Incomes taxes	Income taxes —The Company was treated as a disregarded entity wholly owned by New Mountain Finance Advisers, L.L.C. for the period beginning with the date of its inception on March 18, 2022 through May 5, 2022. The Company intends to elect to be treated as a RIC for U.S. federal income tax purposes under Subchapter M of the Code with the filing of its first tax return for the year ending December 31, 2022, and thereafter intends to comply with the requirements to qualify and maintain its status as a RIC annually. As a RIC, the Company is not subject to U.S. federal income tax on the portion of taxable income and gains timely distributed to its unitholders. To qualify and be subject to tax treatment as a RIC, the Company is required to meet certain income and asset diversification tests in addition to timely distributing at least 90.0% of its investment company taxable income, as defined by the Code. Since U.S. federal income tax regulations differ from GAAP, distributions in accordance with tax regulations may differ from net investment income and realized gains recognized for financial reporting purposes. Differences between taxable income and the results of operations for financial reporting purposes may be permanent or temporary in nature. Permanent differences are reclassified among capital accounts in the consolidated financial statements to reflect their tax character. Differences in classification may also result from the treatment of short-term gains as ordinary income for U.S. federal income tax purposes. For U.S. federal income tax purposes, distributions paid to unitholders of the Company are reported as ordinary income, return of capital, long term capital gains or a combination thereof. The Company will be subject to a 4.0% nondeductible federal excise tax on certain undistributed income unless the Company distributes, in a timely manner as required by the Code, an amount at least equal to the sum of (1) 98.0% of its respective net ordinary income earned for the calendar year and (2) 98.2% of its respective capital gain net income for the one-year period ending October 31 in the calendar year.
Distributions	Distributions —Distributions to the Company's unitholders are recorded on the record date as set by the Company's board of directors. The Company intends to make timely distributions to its unitholders that will be sufficient to enable the Company to qualify and maintain its status as a RIC. The Company intends to distribute approximately all of its net investment income on a quarterly basis and substantially all of its taxable income on an annual basis, except that the Company may retain certain net capital gains for reinvestment.
Earnings per unit	Earnings per Unit —The Company's earnings per unit ("EPU") amounts have been computed based on the weighted-average number of Units outstanding for the period. Basic EPU is computed by dividing net increase (decrease) in members' capital resulting from operations by the weighted average number of Units outstanding during the period of computation. Diluted EPU is computed by dividing net increase (decrease) in members' capital resulting from operations by the weighted average number of Units assuming all potential Units had been issued, and its related net impact to members' capital accounted
Foreign securities	Foreign securities—The accounting records of the Company are maintained in U.S. dollars. Investment securities denominated in foreign currencies are translated into U.S. dollars based on the rate of exchange of such currencies on the date of valuation. Purchases and sales of investment securities and income and expense items denominated in foreign currencies are translated into U.S. dollars based on the rate of exchange of such currencies on the respective dates of the transactions. The Company does not isolate that portion of the results of operations resulting from changes in foreign exchange rates on investments from the fluctuations arising from changes in market prices of securities held. Such fluctuations are included with "Net change in unrealized appreciation (depreciation) of investments" and "Net realized gains (losses) on investments" in the Company's Consolidated Statement of Operations.
Use of estimates	Use of estimates —The preparation of the Company's consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the Company's consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Changes in the economic environment, financial markets, and other metrics used in determining these estimates could cause actual results to differ from the estimates used, and the differences could be material.
Fair value	Fair Value Fair value is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosure ("ASC 820") establishes a fair value hierarchy that prioritizes and ranks the inputs to valuation techniques used in measuring investments at fair value. The hierarchy classifies the inputs used in measuring fair value into three levels as follows: Level I —Quoted prices (unadjusted) are available in active markets for identical investments and the Company has the ability to access such quotes as of the reporting date. The type of investments which would generally be included in Level I include active exchange-traded equity securities and exchange-traded derivatives. As required by ASC 820, the Company, to the extent that it holds such investments, does not adjust the quoted price for these investments, even in situations where the Company holds a large position and a sale could reasonably impact the quoted price. Level II —Pricing inputs are observable for the investments, either directly or indirectly, as of the reporting date, but are not the same as those used in Level I. Level II inputs include the following: • Quoted prices for similar assets or liabilities in active markets; • Quoted prices for identical or similar assets or liabilities in non-active markets (examples include corporate and municipal bonds, which trade infrequently); • Pricing models whose inputs are observable for substantially the full term of the asset or liability (examples include most over-the-counter derivatives, including foreign exchange forward contracts); and • Pricing models whose inputs are derived principally from or corroborated by observable market data through correlation or other means for substantially the full term of the asset or liability. Level III —Pricing inputs are unobservable for the investment and include situations where there is little, if any, market activity for the investment. The inputs used to measure fair value may fall into different levels. In all instances when the inputs fall within different levels of the hierarchy, the level within which the fair value measurement is categorized is based on the lowest level of input that is significant to the fair value measurement in its entirety. As such, a Level III fair value measurement may include inputs that are both observable and unobservable. Gains and losses for such assets categorized within the Level III table below may include changes in fair value that are attributable to both observable inputs and unobservable inputs. The inputs into the determination of fair value require significant judgment or estimation by management and consideration of factors specific to each investment. A review of the fair value hierarchy classifications is conducted on a quarterly basis. Changes in the observability of valuation inputs may result in the transfer of certain investments within the fair value hierarchy from period to period.
Recent accounting standards updates	Recent Accounting Standards Updates In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update No. 2020-04, Reference Rate Reform (Topic 848) : Facilitation of the Effects of Reference Rate Reform on Financial Reporting ("ASU 2020-04"). The amendments in ASU 2020-04 provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The standard is effective as of March 12, 2020 through December 31, 2022. Management is currently evaluating the impact of the optional guidance on the Company's consolidated financial statements and disclosures. The Company did not utilize the optional expedients and exceptions provided by ASU 2020-04 during the period from May 9, 2022 (commencement of operations) to March 31, 2023. In December 2022, the FASB issued ASU No. 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848, which deferred the sunset day of this guidance to December 31, 2024. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2023
Schedule of Investments [Abstract]
Schedule of Investments	At March 31, 2023, the Company's investments consisted of the following: Investment Cost and Fair Value by Type Cost Fair Value First lien $ 165,291 $ 164,905 Second lien 13,902 15,299 Subordinated 10,874 10,929 Equity and other 828 827 Total investments $ 190,895 $ 191,960 Investment Cost and Fair Value by Industry Cost Fair Value Software $ 104,533 $ 105,443 Business Services 46,122 45,926 Healthcare 16,127 16,157 Consumer Services 10,398 10,208 Education 6,273 6,886 Distribution & Logistics 5,540 5,410 Financial Services 1,902 1,930 Total investments $ 190,895 $ 191,960 At December 31, 2022, the Company's investments consisted of the following: Investment Cost and Fair Value by Type Cost Fair Value First lien $ 100,860 $ 99,866 Second lien 10,991 11,852 Subordinated 10,806 10,730 Equity and other 779 763 Total investments $ 123,436 $ 123,211 Investment Cost and Fair Value by Industry Cost Fair Value Software $ 60,274 $ 60,506 Business Services 29,285 29,035 Healthcare 14,727 14,506 Consumer Services 6,343 6,138 Education 5,442 5,858 Distribution & Logistics 5,459 5,321 Financial Services 1,906 1,847 Total investments $ 123,436 $ 123,211

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Portfolio Investments by Level in the Fair Value Hierarchy	The following table summarizes the levels in the fair value hierarchy that the Company's portfolio investments fall into as of March 31, 2023: Total Level I Level II Level III First lien $ 164,905 $ — $ 15,284 $ 149,621 Second lien 15,299 — 7,031 8,268 Subordinated 10,929 — 7,889 3,040 Equity and other 827 — — 827 Total investments $ 191,960 $ — $ 30,204 $ 161,756 The following table summarizes the levels in the fair value hierarchy that the Company's portfolio investments fall into as of December 31, 2022: Total Level I Level II Level III First lien $ 99,866 $ — $ 6,518 $ 93,348 Second lien 11,852 — 4,613 7,239 Subordinated 10,730 — 7,653 3,077 Equity and other 763 — — 763 Total investments $ 123,211 $ — $ 18,784 $ 104,427
Changes in Level III Portfolio Investments	The following table summarizes the changes in fair value of Level III portfolio investments for the three months ended March 31, 2023, as well as the portion of appreciation (depreciation) included in income attributable to unrealized appreciation (depreciation) related to those assets and liabilities still held by the Company at March 31, 2023: Total First Lien Second Lien Subordinated Equity and other Fair Value, December 31, 2022 $ 104,427 $ 93,348 $ 7,239 $ 3,077 $ 763 Total gains or losses included in earnings: Net change in unrealized appreciation (depreciation) of investments 1,011 804 229 (37) 15 Purchases, including revolver fundings 57,190 56,341 800 — 49 Proceeds from paydowns of investments (872) (872) — — — Fair Value, March 31, 2023 $ 161,756 $ 149,621 $ 8,268 $ 3,040 $ 827 Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period: $ 1,011 $ 804 $ 229 $ (37) $ 15
Schedule of Fair Value Measurement Inputs and Valuation Techniques	The unobservable inputs used in the fair value measurement of the Company's Level III investments as of March 31, 2023 were as follows: Range Type Fair Value as of March 31, 2023 Approach Unobservable Input Low High Weighted First lien $ 136,059 Market & income approach EBITDA multiple 8.0x 37.8x 17.4x Revenue multiple 4.5x 16.6x 9.2x Discount rate 8.0 % 12.9 % 10.4 % 1,930 Market quote Broker quote N/A N/A N/A 11,632 Other N/A (2) N/A N/A N/A Second lien 8,268 Market & income approach EBITDA multiple 14.0x 18.0x 16.0x Market & income approach Discount rate 10.7 % 12.2 % 11.9 % Subordinated 3,040 Market & income approach EBITDA multiple 19.0x 24.5x 21.8x Discount rate 13.1 % 14.4 % 13.8 % Equity and other 827 Market & income approach Revenue multiple 4.5x 5.5x 5.0x Discount rate 14.4 % 15.3 % 14.9 % $ 161,756 (1) Unobservable inputs were weighted by the relative fair value of the investments. (2) Fair value was determined based on transaction pricing or recent acquisition or sale as the best measure of fair value with no material changes in operations of the related portfolio company since the transaction date. The unobservable inputs used in the fair value measurement of the Company's Level III investments as of December 31, 2022 were as follows: Range Type Fair Value as of December 31, 2022 Approach Unobservable Input Low High Weighted First lien $ 82,517 Market & income approach EBITDA multiple 10.0x 38.0x 19.8x Revenue multiple 8.0x 17.0x 10.4x Discount rate 8.8 % 12.5 % 10.5 % 10,831 Other N/A (2) N/A N/A N/A Second lien 7,239 Market & income approach EBITDA multiple 14.0x 18.0x 16.0x Discount rate 11.2 % 12.6 % 12.3 % Subordinated 3,077 Market & income approach EBITDA multiple 23.5x 23.5x 23.5x Discount rate 14.8 % 14.8 % 14.8 % Equity and other 763 Market & income approach EBITDA multiple 25.0x 25.0x 25.0x Discount rate 14.9 % 14.9 % 14.9 % $ 104,427 (1) Unobservable inputs were weighted by the relative fair value of the investments.
Schedule of Principal Amounts and Fair Values of Borrowings	The BMO Subscription Line (as defined below) and the UBS Credit Facility (as defined below) are considered Level III investments. See Note 6. Borrowings for details. The following are the principal amount and fair value of the Company’s borrowings as of March 31, 2023. Fair value is estimated by discounting remaining payments using applicable current market rates, which take into account changes in the Company’s marketplace credit ratings, or market quotes, if available. As of March 31, 2023 December 31, 2022 Principal Amount Fair Value Principal Amount Fair Value BMO Subscription Line $ 45,000 $ 45,013 $ 53,700 53,674 UBS Credit Facility 58,400 59,046 N/A N/A Total $ 103,400 $ 104,059 $ 53,700 $ 53,674 N/A Not applicable.

Agreements and Related Parties

Agreements and Related Parties (Tables)	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
Schedule of Management Fees and Incentive Fees	The following table summarizes the management fees and incentive fees incurred by the Company for the three months ended March 31, 2023. Three Months Ended March 31, 2023 Management fee $ 372 Less: management fee waiver (186) Net management fee 186 Incentive fee, excluding accrued incentive fees on capital gains $ 369

Members' Capital (Tables)

Members' Capital (Tables)	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Schedule of Capital Drawdowns Delivered Pursuant to Subscription Agreements	The following table summarizes the total Units issued and proceeds received related to capital drawdowns delivered pursuant to the Subscription Agreements for the three months ended March 31, 2023. Drawdown Date Unit Issue Date Units Issued Aggregate Offering Price February 23, 2023 March 9, 2023 982,500 $ 9,825
Schedule of Distributions Declared on Common Units	The following table reflects the distributions declared on the Company's common units for the three months ended March 31, 2023. Date Declared Record Date Payment Date Per Unit Amount March 2, 2023 March 8, 2023 April 20, 2023 $ 0.175 March 30, 2023 March 31, 2023 April 20, 2023 0.150 $ 0.325

Earnings (Loss) Per Unit (Table

Earnings (Loss) Per Unit (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following information sets forth the computation of basic net decrease in the Company's members' capital per unit resulting from operations for the three months ended March 31, 2023: Three Months Ended March 31, 2023 Earnings (Loss) per unit—basic & diluted Numerator for basic & diluted earnings per unit: $ 3,383 Denominator for basic & diluted weighted average unit: 7,776,914 Basic & diluted earnings per unit: $ 0.43

Financial Highlights (Tables)

Financial Highlights (Tables)	3 Months Ended
	Mar. 31, 2023
Investment Company [Abstract]
Schedule of Financial Highlights	The following information sets forth the Company's financial highlights for the three months ended March 31, 2023. Three Months Ended March 31, 2023 Per unit data(1): Members' capital, December 31, 2022 $ 9.77 Net investment income 0.27 Net realized and unrealized gains(2) 0.18 Total net increase 0.45 Distributions declared to unitholders from net investment income (0.33) Members' capital, March 31, 2023 $ 9.89 Total return based on members' capital(3) 4.63 % Units outstanding at end of period 8,508,331 Average weighted units outstanding for the period 7,776,914 Average members' capital for the period $ 76,036 Ratio to average members' capital: Net investment income(4) 11.97 % Total expenses, before waivers/reimbursements(4) 17.13 % Total expenses, net of waivers/reimbursements(4) 16.13 % Average debt outstanding—BMO Subscription Line $ 65,306 Average debt outstanding—UBS Credit Facility $ 17,106 Asset coverage ratio 181.36 % Portfolio turnover 0.22 % Capital Commitments $ 282,100 Funded Capital Commitments $ 84,630 % of Capital Commitments funded 30.00 % (1) Per unit data is based on weighted average units outstanding for the respective period (except for distributions declared to unitholders, which are based on actual rate per unit). (2) The total amount shown may not correspond with the aggregate amount for the period as it includes the effect of the timing of capital transactions which for the three months ended March 31, 2023 was $0.02. (3) Total return is calculated assuming an initial purchase price of $10.00 per Unit and a sale at members' capital per Unit on the last day of the period. Dividends and distributions, if any, are assumed for purposes of this calculation, to be reinvested at members' capital per Unit on the last day of the respective quarter. Total return calculation is not annualized. (4) Annualized, except organizational and offering costs.

Formation and Business Purpose

Formation and Business Purpose (Details) - USD ($) $ in Thousands		3 Months Ended
	May 04, 2022	Mar. 31, 2023
Summary of Investment Holdings [Line Items]
Investment period	4 years
Term of company	6 years
Term of company, extension period	1 year
Term of company, additional extension period	1 year
Minimum
Summary of Investment Holdings [Line Items]
EBITDA as defined for middle market business		$ 10,000
Maximum
Summary of Investment Holdings [Line Items]
EBITDA as defined for middle market business		$ 200,000
Private Placement
Summary of Investment Holdings [Line Items]
Offering period	24 months

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands		3 Months Ended
	May 03, 2022 USD ($)	Mar. 31, 2023 USD ($) investment	Dec. 31, 2022 investment
Accounting Policies [Abstract]
Cash equivalents		$ 0
PIK dividends		25
PIK interest		$ 93
Investments threshold period past due for nonaccrual status		30 days
Number of investments on non-accrual status | investment		0	0
Related Party Transaction [Line Items]
Amortization period for deferred offering costs		12 months
Investment Management Agreement | Affiliated entity
Related Party Transaction [Line Items]
Organizational and offering expenses, reduction to base management fee, threshold	$ 2,500	$ 2,500
Organizational and offering expenses, reduction to base management fee, multiplier	0.50%	0.50%

Investments - Investment Cost a

Investments - Investment Cost and Fair Value by Type and by Industry (Details) - USD ($) $ in Thousands	Mar. 31, 2023		Dec. 31, 2022
Schedule of Investments [Line Items]
Cost	$ 190,895	[1]	$ 123,436	[2]
Fair Value	191,960	[1]	123,211	[2]
Software
Schedule of Investments [Line Items]
Cost	104,533		60,274
Fair Value	105,443		60,506
Business Services
Schedule of Investments [Line Items]
Cost	46,122		29,285
Fair Value	45,926		29,035
Healthcare
Schedule of Investments [Line Items]
Cost	16,127		14,727
Fair Value	16,157		14,506
Consumer Services
Schedule of Investments [Line Items]
Cost	10,398		6,343
Fair Value	10,208		6,138
Education
Schedule of Investments [Line Items]
Cost	6,273		5,442
Fair Value	6,886		5,858
Distribution & Logistics
Schedule of Investments [Line Items]
Cost	5,540		5,459
Fair Value	5,410		5,321
Financial Services
Schedule of Investments [Line Items]
Cost	1,902		1,906
Fair Value	1,930		1,847
First lien
Schedule of Investments [Line Items]
Cost	165,291		100,860
Fair Value	164,905		99,866
Second lien
Schedule of Investments [Line Items]
Cost	13,902		10,991
Fair Value	15,299		11,852
Subordinated
Schedule of Investments [Line Items]
Cost	10,874		10,806
Fair Value	10,929		10,730
Equity and other
Schedule of Investments [Line Items]
Cost	828		779
Fair Value	$ 827		$ 763
[1]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.[2]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.

Investments - Narrative (Detail

Investments - Narrative (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Unfunded Commitments on Revolving Credit Facilities
Investment Company, Nonconsolidated Subsidiary [Line Items]
Principal amount	$ 9,948,000	$ 5,939,000
Unfunded Commitments on Bridge Facilities
Investment Company, Nonconsolidated Subsidiary [Line Items]
Principal amount	0	0
Unfunded Commitments on Delayed Draws or Other Future Funding Commitments
Investment Company, Nonconsolidated Subsidiary [Line Items]
Principal amount	$ 29,539,000	$ 30,263,000

Fair Value - Fair Value Levels

Fair Value - Fair Value Levels (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	$ 191,960	$ 123,211
First lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	164,905	99,866
Second lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	15,299	11,852
Subordinated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	10,929	10,730
Equity and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	827	763
Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Level I | First lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Level I | Second lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Level I | Subordinated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Level I | Equity and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	30,204	18,784
Level II | First lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	15,284	6,518
Level II | Second lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	7,031	4,613
Level II | Subordinated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	7,889	7,653
Level II | Equity and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	161,756	104,427
Level III | First lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	149,621	93,348
Level III | Second lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	8,268	7,239
Level III | Subordinated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	3,040	3,077
Level III | Equity and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	$ 827	$ 763

Fair Value - Level III Rollforw

Fair Value - Level III Rollforward (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Total
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 104,427
Net change in unrealized appreciation (depreciation) of investments	1,011
Purchases, including revolver fundings	57,190
Proceeds from paydowns of investments	(872)
Ending balance	161,756
Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period:	1,011
First lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	93,348
Net change in unrealized appreciation (depreciation) of investments	804
Purchases, including revolver fundings	56,341
Proceeds from paydowns of investments	(872)
Ending balance	149,621
Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period:	804
Second lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	7,239
Net change in unrealized appreciation (depreciation) of investments	229
Purchases, including revolver fundings	800
Proceeds from paydowns of investments	0
Ending balance	8,268
Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period:	229
Subordinated
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3,077
Net change in unrealized appreciation (depreciation) of investments	(37)
Purchases, including revolver fundings	0
Proceeds from paydowns of investments	0
Ending balance	3,040
Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period:	(37)
Equity and other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	763
Net change in unrealized appreciation (depreciation) of investments	15
Purchases, including revolver fundings	49
Proceeds from paydowns of investments	0
Ending balance	827
Unrealized appreciation (depreciation) for the period relating to those Level III assets that were still held by the Company at the end of the period:	$ 15

Fair Value - Unobservable Input

Fair Value - Unobservable Inputs (Details) $ in Thousands	Mar. 31, 2023 USD ($)		Dec. 31, 2022 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 191,960	[1]	$ 123,211	[2]
Level III
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	161,756		104,427
Level III | First lien | Market & income approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 136,059		$ 82,517
Level III | First lien | Market & income approach | EBITDA multiple | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	8		10
Level III | First lien | Market & income approach | EBITDA multiple | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	37.8		38
Level III | First lien | Market & income approach | EBITDA multiple | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	17.4		19.8
Level III | First lien | Market & income approach | Revenue multiple | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	4.5		8
Level III | First lien | Market & income approach | Revenue multiple | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	16.6		17
Level III | First lien | Market & income approach | Revenue multiple | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	9.2		10.4
Level III | First lien | Market & income approach | Discount rate | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.080		0.088
Level III | First lien | Market & income approach | Discount rate | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.129		0.125
Level III | First lien | Market & income approach | Discount rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.104		0.105
Level III | First lien | Market quote
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 1,930
Level III | First lien | Other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	11,632		$ 10,831
Level III | Second lien | Market & income approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 8,268		$ 7,239
Level III | Second lien | Market & income approach | EBITDA multiple | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	14		14
Level III | Second lien | Market & income approach | EBITDA multiple | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	18		18
Level III | Second lien | Market & income approach | EBITDA multiple | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	16		16
Level III | Second lien | Market & income approach | Discount rate | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.107		0.112
Level III | Second lien | Market & income approach | Discount rate | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.122		0.126
Level III | Second lien | Market & income approach | Discount rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.119		0.123
Level III | Subordinated | Market & income approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 3,040		$ 3,077
Level III | Subordinated | Market & income approach | EBITDA multiple | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	19		23.5
Level III | Subordinated | Market & income approach | EBITDA multiple | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	24.5		23.5
Level III | Subordinated | Market & income approach | EBITDA multiple | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	21.8		23.5
Level III | Subordinated | Market & income approach | Discount rate | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.131		0.148
Level III | Subordinated | Market & income approach | Discount rate | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.144		0.148
Level III | Subordinated | Market & income approach | Discount rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.138		0.148
Level III | Equity and other | Market & income approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 827		$ 763
Level III | Equity and other | Market & income approach | EBITDA multiple | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input			25
Level III | Equity and other | Market & income approach | EBITDA multiple | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input			25
Level III | Equity and other | Market & income approach | EBITDA multiple | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input			25
Level III | Equity and other | Market & income approach | Revenue multiple | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	4.5
Level III | Equity and other | Market & income approach | Revenue multiple | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	5.5
Level III | Equity and other | Market & income approach | Revenue multiple | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	5
Level III | Equity and other | Market & income approach | Discount rate | Low
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.144		0.149
Level III | Equity and other | Market & income approach | Discount rate | High
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.153		0.149
Level III | Equity and other | Market & income approach | Discount rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.149		0.149
[1]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.[2]New Mountain Guardian IV BDC, L.L.C. (the "Company") generally acquires its investments in private transactions exempt from registration under the Securities Act of 1933, as amended (the "Securities Act"). These investments are generally subject to certain limitations on resale, and may be deemed to be "restricted securities" under the Securities Act.

Fair Value - Principal Amount a

Fair Value - Principal Amount and Fair Values of Borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Principal Amount
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Borrowings	$ 103,400	$ 53,700
Principal Amount | Line of Credit | Revolving Credit Facility | BMO Subscription Line
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Borrowings	45,000	53,700
Principal Amount | Line of Credit | Revolving Credit Facility | UBS Credit Facility
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Borrowings	58,400
Fair Value
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Borrowings	104,059	53,674
Fair Value | Line of Credit | Revolving Credit Facility | BMO Subscription Line
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Borrowings	45,013	$ 53,674
Fair Value | Line of Credit | Revolving Credit Facility | UBS Credit Facility
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Borrowings	$ 59,046

Agreements and Related Partie_2

Agreements and Related Parties - Narrative (Details)			3 Months Ended	12 Months Ended
	Jan. 24, 2023	May 03, 2022 USD ($)	Mar. 31, 2023 USD ($) component	May 09, 2023	Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items]
Incentive fees waived			$ 0
Incentive fee			369,000
Payable to affiliate			209,000		$ 167,000
Investment Management Agreement | Affiliated entity
Related Party Transaction [Line Items]
Agreement term	12 months
Base management fee percentage		1.15%
Minimum base management fee		$ 0
Organizational and offering expenses, reduction to base management fee, threshold		$ 2,500,000	$ 2,500,000
Organizational and offering expenses, reduction to base management fee, multiplier		0.50%	0.50%
Number of incentive fee components | component			2
Return of incentive fee upon termination of company, cumulative incentive fees threshold, percentage		15%
Return of incentive fee upon termination of company, cumulative internal rate of return threshold, percentage		7%
Investment Management Agreement | Affiliated entity | Forecast
Related Party Transaction [Line Items]
Base management fee percentage				0.575%
Base management fee reduction percentage through 1 year anniversary of initial drawdown date				50%
Quarterly hurdle rate | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		1.75%
Annualized hurdle rate | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		7%
Pre-Incentive Fee Net Investment Income below catch-up threshold | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		100%
Quarterly catch-up threshold | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		2.059%
Annualized catch-up threshold | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		8.235%
Pre-Incentive Fee Net Investment Income exceeds catch-up threshold | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		15%
Realized capital gains
Related Party Transaction [Line Items]
Incentive fee			$ 0
Realized capital gains, annualized cumulative internal rate of return | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		7%
Realized capital gains, cumulative net realized gains | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		100%
Realized capital gains, cumulative net realized gains threshold | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		15%
Realized capital gains, additional undistributed cumulative net realized gains | Affiliated entity
Related Party Transaction [Line Items]
Incentive fee percentage		15%
Expense Limitation snd Reimbursement Agreement | Affiliated entity
Related Party Transaction [Line Items]
Management fee waiver, percentage applied to calculate Specified Expense Cap		0.40%
Management fee waiver, capital commitments threshold		$ 750,000,000
Period for reimbursement of compensation waived and other expenses		36 months
Period for recapture of specified expenses		36 months
Administration Agreement
Related Party Transaction [Line Items]
Indirect administrative expenses			146,000
Fees waived by the administrator			0
Payable to affiliate			$ 146,000		$ 204,000

Agreements and Related Partie_3

Agreements and Related Parties - Management Fees and Incentive Fees (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Related Party Transaction [Line Items]
Management fee	$ 372
Less: management fee waiver	(186)
Net management fee	186
Incentive fee	369
Incentive fee, excluding accrued incentive fees on capital gains
Related Party Transaction [Line Items]
Incentive fee	$ 369

Borrowings (Details)

Borrowings (Details) - USD ($)			3 Months Ended
	Jan. 25, 2023	May 09, 2022	Mar. 31, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Amortization of financing costs			$ 64,000
BMO Subscription Line
Line of Credit Facility [Line Items]
Credit facility outstanding balance			45,000,000	$ 53,700,000
UBS Credit Facility
Line of Credit Facility [Line Items]
Credit facility outstanding balance			58,400,000	0
Revolving Credit Facility | BMO Subscription Line
Line of Credit Facility [Line Items]
Credit facility outstanding balance			45,000,000	$ 53,700,000
Revolving Credit Facility | UBS Credit Facility
Line of Credit Facility [Line Items]
Credit facility outstanding balance			58,400,000
Revolving Credit Facility | Line of Credit | BMO Subscription Line
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 96,000,000
Period for outstanding balance due on demand		15 days
Period for outstanding balance after date of advance		6 months
Interest expense			1,205,000
Amortization of financing costs			$ 4,000
Weighted average interest rate			7.50%
Effective interest rate			7.50%
Revolving Credit Facility | Line of Credit | UBS Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 250,000,000
Interest expense			$ 459,000
Non-usage fee			196,000
Amortization of financing costs			$ 59,000
Weighted average interest rate			7.50%
Effective interest rate			22.90%
Borrowing capacity, first percentage	30%
Borrowing capacity, second percentage	40%
Borrowing capacity, fourth percentage	65%
Borrowing capacity, fifth percentage	0.700
Borrowing capacity, sixth percentage	75%
Borrowing capacity, third percentage	50%
Revolving Credit Facility | Line of Credit | Prime Rate | BMO Subscription Line
Line of Credit Facility [Line Items]
Interest rate margin plus (minus)		(0.25%)
Revolving Credit Facility | Line of Credit | SOFR, Quoted Rate | BMO Subscription Line
Line of Credit Facility [Line Items]
Interest rate margin plus (minus)		2.50%
Revolving Credit Facility | Line of Credit | Term SOFR | UBS Credit Facility
Line of Credit Facility [Line Items]
Interest rate margin plus (minus)	2.85%
Revolving Credit Facility | Line of Credit | Three-month term SOFR | BMO Subscription Line
Line of Credit Facility [Line Items]
Interest rate margin plus (minus)		0.15%

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Financing commitment letter to purchase investments
Other Commitments [Line Items]
Other commitments	$ 0	$ 33,881,000
Unfunded Commitments on Revolving Credit Facilities
Other Commitments [Line Items]
Principal amount	9,948,000	5,939,000
Bridge financing commitments
Other Commitments [Line Items]
Principal amount	0	0
Other Future Funding Commitments
Other Commitments [Line Items]
Principal amount	$ 29,539,000	$ 30,263,000

Members' Capital (Details)

Members' Capital (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	Mar. 30, 2023	Mar. 09, 2023	Mar. 02, 2023	Mar. 31, 2023
Equity [Abstract]
Units Issued (in shares)		982,500		982,500
Aggregate Offering Price		$ 9,825		$ 9,825
Distributions declared (in dollars per share)	$ 0.150		$ 0.175	$ 0.325

Earnings (Loss) Per Unit (Detai

Earnings (Loss) Per Unit (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares
Earnings Per Share [Abstract]
Numerator for basic & diluted earnings per unit | $	$ 3,383
Average weighted units outstanding for the period - basic (in shares) | shares	7,776,914
Average weighted units outstanding for the period - diluted (in shares) | shares	7,776,914
Basic earnings per unit (in dollars per share) | $ / shares	$ 0.43
Diluted earnings per unit (in dollars per share) | $ / shares	$ 0.43

Financial Highlights (Details)

Financial Highlights (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended
	Mar. 30, 2023	Mar. 02, 2023	Mar. 31, 2023	Dec. 31, 2022
Investment Company, Financial Highlights [Roll Forward]
Member's capital, beginning balance (in dollars per share)			$ 9.77
Net investment income (in dollars per share)			0.27
Net realized and unrealized gains (in dollars per share)			0.18
Total net increase (in dollars per share)			0.45
Distributions declared to unitholders from net investment income (in dollars per share)	$ (0.150)	$ (0.175)	(0.325)
Member's capital, ending balance (in dollars per share)			$ 9.89
Total return based on members' capital			4.63%
Units outstanding at end of period (in shares)			8,508,331	7,525,831
Average weighted units outstanding for the period - diluted (in shares)			7,776,914
Average weighted units outstanding for the period - basic (in shares)			7,776,914
Average members' capital for the period			$ 76,036
Ratio to average members' capital:
Net investment income			11.97%
Total expenses, before waivers/reimbursements			17.13%
Total expenses, net of waivers/reimbursements			16.13%
Asset coverage ratio			181.36%
Portfolio turnover			0.22%
Capital Commitments			$ 282,100
Funded Capital Commitments			$ 84,630
% of Capital Commitments funded			30%
Effect of the timing of capital transactions (in dollars per share)			$ 0.02
Initial purchase price used to calculate Total return (in dollars per share)			$ 10
BMO Subscription Line
Ratio to average members' capital:
Average debt outstanding			$ 65,306
UBS Credit Facility
Ratio to average members' capital:
Average debt outstanding			$ 17,106