Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2024

Accounting Policies [Abstract]

Summary of Impact of Restatements to Specific Line Items Previously Reported in Consolidated Financial Statements

The following tables reflect the impact of the restatements to the specific line items presented in the Company’s previously reported Consolidated Balance Sheets as of December 31, 2024 and 2023.

		As of December 31, 2024
ASSETS	Adj Reference	As Reported			Adjustment			As Restated
Current Assets
Cash and cash equivalents		$	77,567		$	(1,546	)	$	76,021
Accounts receivable, less allowance for credit losses of $1,300 as of December 31, 2024			178,030			—			178,030
Other receivables			9,775			—			9,775
Income tax receivable			5,461			—			5,461
Inventory, net	ADJ 3		269,337			(7,780	)		261,557
Assets held for sale			11,901			—			11,901
Prepaid expenses and other current assets			58,534			(2,139	)		56,395
Total Current Assets			610,605			(11,465	)		599,140
Property, plant and equipment, net			102,942			3,512			106,454
Deferred tax assets, net			17,826			—			17,826
Goodwill			52,918			—			52,918
Intangibles, net			284,893			—			284,893
Other non-current assets			78,128			—			78,128
Long-term investments			32,060			—			32,060
Total Assets		$	1,179,372		$	(7,953	)	$	1,171,419
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable		$	170,451		$	1,374		$	171,825
Unearned revenue			52,701			—			52,701
Accrued expenses and other liabilities			35,704			(1,546	)		34,158
Accrued wages and benefits			32,853			—			32,853
Income tax payable			1,936			—			1,936
Total Current Liabilities			293,645			(172	)		293,473
Non-current revolving credit agreement outstanding			189,576			-			189,576
Deferred tax liabilities			30,690			(318	)		30,372
Non-current unearned revenue			22,065			—			22,065
Non-current pension liability			8,983			—			8,983
Deferred compensation liability			33,203			—			33,203
Non-current lease obligations			25,925			—			25,925
Other non-current liabilities			17,928			—			17,928
Total Liabilities			622,015			(490	)		621,525
Commitments and contingencies (see Note 18)
Redeemable Non-Controlling Interest			422,943			—			422,943
Equity
Common stock, par value $0.01 per share; 200,000 shares authorized;    79,483 shares issued and 79,218 outstanding as of December 31, 2024			795			—			795
Additional paid-in capital			808,913			—			808,913
Accumulated other comprehensive income	ADJ 3, 4		10,897			357			11,254
Retained deficit	ADJ 3, 4		(680,993	)		(7,820	)		(688,813	)
Less treasury stock at cost: 266 shares as of December 31, 2024			(5,198	)		—			(5,198	)
Total Equity			134,414			(7,463	)		126,951
Total Liabilities and Equity		$	1,179,372		$	(7,953	)	$	1,171,419

		As of December 31, 2023
ASSETS	Adj Reference	As Reported			Adjustment			As Restated
Current Assets
Cash and cash equivalents		$	87,167		$	—		$	87,167
Accounts receivable, less allowance for credit losses of $400 as of December 31, 2023			216,445			(6,708	)		209,737
Other receivables			17,450			—			17,450
Income tax receivable			7,933			(4,735	)		3,198
Inventory, net	ADJ 3		362,295			(1,871	)		360,424
Prepaid expenses and other current assets			45,566			(4,575	)		40,991
Total Current Assets			736,856			(17,889	)		718,967
Property, plant and equipment, net			113,582			4,575			118,157
Deferred tax assets, net	ADJ 4		25,787			3,507			29,294
Goodwill	ADJ 4		353,415			4,735			358,150
Intangibles, net			337,423			—			337,423
Other non-current assets			87,706			—			87,706
Long-term investments			27,743			—			27,743
Total Assets		$	1,682,512		$	(5,072	)	$	1,677,440
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable		$	162,922		$	—		$	162,922
Unearned revenue			46,731			(4,231	)		42,500
Accrued expenses and other liabilities	ADJ 1		37,607			(1,403	)		36,204
Accrued wages and benefits			27,030			122			27,152
Income tax payable	ADJ 4		5,221			—			5,221
Total Current Liabilities			279,511			(5,512	)		273,999
Non-current revolving credit agreement outstanding			195,000			—			195,000
Deferred tax liabilities	ADJ 4		35,655			(89	)		35,566
Non-current unearned revenue			25,109			(2,477	)		22,632
Non-current pension liability			12,543			—			12,543
Deferred compensation liability			29,039			—			29,039
Non-current lease obligations			31,420			—			31,420
Other non-current liabilities			28,657			—			28,657
Total Liabilities			636,934			(8,078	)		628,856
Commitments and contingencies (see Note 20)
Redeemable Non-Controlling Interest	ADJ 2		451,756			(8,429	)		443,327
Equity
Common stock, par value $0.01 per share; 200,000 shares authorized;    78,970 shares issued and 78,674 outstanding as of December 31, 2023			790			—			790
Additional paid-in capital			795,304			(836	)		794,468
Accumulated other comprehensive income	ADJ 1		47,461			69			47,530
Retained deficit	ADJ 1, 2, 4		(243,908	)		12,202			(231,706	)
Less treasury stock at cost: 297 shares as of December 31, 2023			(5,825	)		—			(5,825	)
Total Equity			593,822			11,435			605,257
Total Liabilities and Equity		$	1,682,512		$	(5,072	)	$	1,677,440

The following tables reflect the impact of the restatements to the specific line items presented in the Company’s previously reported Consolidated Statement of Loss and the Consolidated Statement of Comprehensive Loss for the years ended December 31, 2024 and 2023.

		Year Ended December 31, 2024
	Adj Reference	As Reported			Adjustment			As Restated
Revenue
Network Solutions		$	738,964		$	—		$	738,964
Services & Support			183,756			—			183,756
Total Revenue			922,720			—			922,720
Cost of Revenue
Network Solutions	ADJ 3		511,070			6,150			517,220
Network Solutions - inventory write-down and other charges			8,597			—			8,597
Services & Support			72,739			—			72,739
Total Cost of Revenue			592,406			6,150			598,556
Gross Profit			330,314			(6,150	)		324,164
Selling, general and administrative expenses			233,369			(451	)		232,918
Research and development expenses			221,463			(5	)		221,458
Goodwill impairment	ADJ 4		292,583			4,770			297,353
Operating Loss			(417,101	)		(10,464	)		(427,565	)
Interest and dividend income			3,058			—			3,058
Interest expense			(22,053	)		—			(22,053	)
Net investment gain			3,587			—			3,587
Other income, net			246			—			246
Loss Before Income Taxes			(432,263	)		(10,464	)		(442,727	)
Income tax expense	ADJ 4		(8,785	)		1,445			(7,340	)
Net Loss		$	(441,048	)	$	(9,019	)	$	(450,067	)
Less: Net Income attributable to non-controlling interest(1)			9,824			—			9,824
Net Loss attributable to ADTRAN Holdings, Inc.		$	(450,872	)	$	(9,019	)	$	(459,891	)
Weighted average shares outstanding – basic			78,928			78,928			78,928
Weighted average shares outstanding – diluted			78,928			78,928			78,928
Loss per common share attributable to ADTRAN Holdings, Inc. – basic		$	(5.67	)	$	(0.12	)	$	(5.79	)
Loss per common share attributable to ADTRAN Holdings, Inc. – diluted		$	(5.67	)	$	(0.12	)	$	(5.79	)
Net Loss		$	(441,048	)	$	(9,019	)	$	(450,067	)
Other Comprehensive Loss, net of tax
Defined benefit plan adjustments			1,479			—			1,479
Foreign currency translation loss	ADJ 3, 4		(38,047	)		292			(37,755	)
Other Comprehensive Loss, net of tax			(36,568	)		292			(36,276	)
Comprehensive Loss, net of tax			(477,616	)		(8,727	)		(486,343	)
Less: Comprehensive Income attributable to non-controlling interest, net of tax			9,824			—			9,824
Comprehensive Loss attributable to ADTRAN Holdings, Inc., net of tax		$	(487,440	)	$	(8,727	)	$	(496,167	)

(1) For the year ended December 31, 2024 we accrued $9.8 million of net income attributable to non-controlling interest, representing the recurring cash compensation earned by non-controlling interest shareholders post-DPLTA

		Year Ended December 31, 2023
	Adj Reference	As Reported			Adjustment			As Restated
Revenue
Network Solutions		$	974,389		$	—		$	974,389
Services & Support			174,711			—			174,711
Total Revenue			1,149,100			—			1,149,100
Cost of Revenue
Network Solutions	ADJ 3		722,582			1,936			724,518
Network Solutions - Inventory Write Down			24,313			—			24,313
Services & Support			69,142			—			69,142
Total Cost of Revenue			816,037			1,936			817,973
Gross Profit			333,063			(1,936	)		331,127
Selling, general and administrative expenses			258,149			461			258,610
Research and development expenses			258,311			—			258,311
Goodwill impairment			37,874			—			37,874
Operating Loss			(221,271	)		(2,397	)		(223,668	)
Interest and dividend income			2,340			—			2,340
Interest expense			(16,299	)		—			(16,299	)
Net investment gain			2,754			—			2,754
Other income (expense), net			1,266			—			1,266
Loss Before Income Taxes			(231,210	)		(2,397	)		(233,607	)
Income tax expense	ADJ 4		(28,133	)		(166	)		(28,299	)
Net Loss		$	(259,343	)	$	(2,563	)	$	(261,906	)
Net Income attributable to non-controlling interest (1)	ADJ 1		8,345			(1,399	)		6,946
Net Loss attributable to ADTRAN Holdings, Inc.		$	(267,688	)	$	(1,164	)	$	(268,852	)
Weighted average shares outstanding – basic			78,416			78,416			78,416
Weighted average shares outstanding – diluted			78,416			78,416			78,416
Loss per common share attributable to ADTRAN Holdings, Inc. – basic		$	(3.41	)	$	(0.01	)	$	(3.43	)
Loss per common share attributable to ADTRAN Holdings, Inc. – diluted		$	(3.41	)	$	(0.01	)	$	(3.43	)
Net Loss		$	(259,343	)	$	(2,563	)	$	(261,906	)
Other Comprehensive Loss, net of tax
Net unrealized gain (loss) on available-for-sale securities			454			—			454
Defined benefit plan adjustments			(1,490	)		—			(1,490	)
Foreign currency translation gain	ADJ 1		22,753			69			22,822
Other Comprehensive Loss, net of tax			21,717			69			21,786
Comprehensive (Loss), net of tax			(237,626	)		(2,494	)		(240,120	)
Less: Comprehensive Income attributable to non-controlling interest	ADJ 1		8,727			(1,399	)		7,328
Comprehensive (Loss) attributable to ADTRAN Holdings, Inc., net of tax		$	(246,353	)	$	(1,095	)	$	(247,448	)

(1) For the year ended December 31, 2023, we have recognized $10.1 million, representing the recurring cash compensation earned by non-controlling interest shareholders post-DPLTA partially offset by a $3.2 million net loss attributable to non-controlling interests pre-DPLTA for the year ended December 31, 2023.

The following tables reflect the impact of the restatement to the specific line items presented in the Company's previously reported Consolidated Statement of Changes in Stockholders Equity for the periods ended December 31, 2024 and 2023:

	Retained Deficit									Accumulated Other Comprehensive Income								Additional paid-in capital
(In thousands)	As Reported			Adjustment			As Restated			As Reported			Adjustment		As Restated			As Reported			Adjustment			As Restated
Balance as of December 31, 2023	$	(243,908	)	$	12,202		$	(231,706	)	$	47,461		$	69	$	47,530		$	795,304		$	(836	)	$	794,468
Net loss		(441,048	)		(9,019	)		(450,067	)		—			—		—			—			—			—
Annual recurring compensation earned		(9,824	)		—			(9,824	)		—			—		—			—			—			—
Remeasurement of redeemable non-controlling interest		—			—			—			—			—		—			(1,175	)		—			(1,175	)
Other comprehensive loss, net of tax		—			—			—			(36,568	)		292		(36,276	)		—			—			—
Deferred compensation adjustments, net of tax		—			—			—			—			—		—			(368	)		—			(368	)
ADTRAN RSUs and restricted stock vested		(1,026	)		—			(1,026	)		—			—		—			—			—			—
ADTRAN stock options exercised		824			—			824			—			—		—			—			—			—
Modification of Stock Options		—			—			—			—			—		—			(190	)		—			(190	)
Redemption of redeemable non-controlling interest		2,986			—			2,986			—			—		—			—			—			—
ADTRAN stock-based compensation expense		—			—			—			—			—		—			14,825			—			14,825
Adtran Networks stock-based compensation expense		—			—			—			—			—		—			517			836			1,353
Balance as of December 31, 2024	$	(691,996	)	$	3,183		$	(688,813	)	$	10,893		$	361	$	11,254		$	808,913		$	-		$	808,913

	Retained Deficit									Accumulated Other Comprehensive Income						Additional paid-in capital
(In thousands)	As Reported			Adjustment			As Restated			As Reported		Adjustment		As Restated		As Reported			Adjustment			As Restated
Balance as of December 31, 2022	$	55,338		$	—		$	55,338		$	26,126	$	—	$	26,126	$	895,834		$	—		$	895,834
Net loss		(256,164	)		(2,563	)		(258,727	)		—		—		—		—			—			—
Annual recurring compensation earned		(11,524	)		1,399			(10,125	)		—		—		—		—			—
Acquisition of Adtran Networks		—			3,762			3,762			—		—		—		—			—
Reclassification and remeasurement from equity to mezzanine equity for non-controlling interests in Adtran Networks		—			—			—			—		—		—		(116,895	)		—			(116,895	)
Mezzanine equity for non-controlling interest in Adtran Networks for Adtran Networks stock options exercised		—			—			—			—		—		—		—			(1,175	)		(1,175	)
Other comprehensive income, net of tax		—			—			—			21,335		69		21,404		—			—
Dividend payments ($0.09 per share)		(21,237	)		—			(21,237	)		—		—		—		—			—			—
Dividends accrued on unvested restricted stock units		8			—			8			—		—		—		—			—			—
Deferred compensation adjustments, net of tax		(145	)		—			(145	)		—		—		—		—			—			—
ADTRAN RSUs and restricted stock vested		(1,115	)		—			(1,115	)		—		—		—		—			—			—
ADTRAN stock options exercised		164			—			164			—		—		—		—			—			—
Redemption of redeemable non-controlling interest		371			—			371			—		—		—		—			—			—
Foreign currency remeasurement of redeemable non-controlling interest		(9,604	)		9,604			—			—		—		—		—			—
Adtran Networks stock options exercised		—			—			—			—		—		—		323			—			323
Modification of stock options		—			—			—			—		—		—		—			339			339
ADTRAN stock-based compensation expense		—			—			—			—		—		—		16,016			—			16,016
Adtran Networks stock-based compensation expense		—			—			—			—		—		—		26			—			26
Balance as of December 31, 2023	$	(243,908	)	$	12,202		$	(231,706	)	$	47,461	$	69	$	47,530	$	795,304		$	(836	)	$	794,468

The following tables reflect the impact of the restatement to the specific line items presented in the Company's previously reported Consolidated Statements of Cash Flows for the years ended December 31, 2024 and 2023:

		Year Ended December 31, 2024
	Adj Reference	As Reported			Adjustment			As Restated
Cash flows from operating activities:
Net Loss		$	(441,048	)	$	(9,019	)	$	(450,067	)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization			90,985			(456	)		90,529
Goodwill impairment	ADJ 4		292,583			4,770			297,353
Amortization of debt issuance cost			3,950			—			3,950
Gain on investments			(5,030	)		—			(5,030	)
Net loss on disposal of property, plant and equipment			1,371			—			1,371
Stock-based compensation expense			15,342			646			15,988
Deferred income taxes			2,247			3,329			5,576
Inventory write down - business efficiency program			4,135			—			4,135
Inventory reserves	ADJ 3		3,980			1,336			5,316
Change in operating assets and liabilities:
Accounts receivable, net			46,108			—			46,108
Other receivables			10,713			—			10,713
Income taxes receivable	ADJ 4		648			—			648
Inventory	ADJ 3		75,171			4,814			79,985
Prepaid expenses, other current assets and other assets			(10,718	)		(2,727	)		(13,445	)
Accounts payable			11,784			(1,546	)		10,238
Accrued expenses and other liabilities			5,519			(646	)		4,873
Income taxes payable			(4,670	)		—			(4,670	)
Net cash provided by operating activities			103,070			501			103,571
Cash flows from investing activities:
Purchases of property, plant and equipment			(32,454	)		(2,047	)		(34,501	)
Purchases of intangibles - developed technology			(30,671	)		—			(30,671	)
Proceeds from sales and maturities of available-for-sale investments			1,240			—			1,240
Purchases of available-for-sale investments			(268	)		—			(268	)
Payments for beneficial interests in securitized accounts receivable			(55	)		—			(55	)
Net cash used in investing activities			(62,208	)		(2,047	)		(64,255	)
Cash flows from financing activities:
Tax withholdings related to stock-based compensation settlements			(1,143	)		—			(1,143	)
Proceeds from stock option exercises			824			—			824
Proceeds from receivables purchase agreement			68,556			—			68,556
Repayments on receivables purchase agreement			(83,772	)		—			(83,772	)
Proceeds from draw on revolving credit agreements			26,000			—			26,000
Repayment of revolving credit agreements			(31,000	)		—			(31,000	)
Redemption of redeemable non-controlling interest			(17,398	)		—			(17,398	)
Payment of annual recurring compensation to non-controlling interest			(10,084	)		—			(10,084	)
Payment of debt issuance cost			(1,994	)		—			(1,994	)
Net cash used in financing activities			(50,011	)		—			(50,011	)
Net decrease in cash and cash equivalents			(9,149	)		(1,546	)		(10,695	)
Effect of exchange rate changes			(451	)		—			(451	)
Cash and cash equivalents, beginning of period			87,167			—			87,167
Cash and cash equivalents, end of period		$	77,567		$	(1,546	)	$	76,021
Supplemental disclosure of cash flow information:
Cash paid for interest		$	20,884		$	—		$	20,884
Cash paid for income taxes, net of refunds		$	6,691		$	—		$	6,691
Cash used in operating activities related to operating leases		$	9,274		$	—		$	9,274
Supplemental disclosure of non-cash investing activities:
Right-of-use assets obtained in exchange for lease obligations		$	5,317		$	—		$	5,317
Purchases of property, plant and equipment included in accounts payable		$	2,635		$	—		$	2,635
Redemption of redeemable non-controlling interest		$	2,986		$	—		$	2,986

		Year Ended December 31, 2023
	Adj Reference	As Reported			Adjustment			As Restated
Cash flows from operating activities:
Net Loss		$	(259,343	)	$	(2,563	)	$	(261,906	)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization			112,949			—			112,949
Goodwill impairment			37,874			—			37,874
Amortization of debt issuance cost			862			—			862
Accretion on available-for-sale investments, net			(22	)		—			(22	)
Gain on investments			(2,900	)		—			(2,900	)
Net loss on disposal of property, plant and equipment			458			—			458
Stock-based compensation expense			16,016			365			16,381
Deferred income taxes	ADJ 4		15,558			166			15,724
Inventory write down			24,313			—			24,313
Inventory reserves			25,546			—			25,546
Other, net			(2,942	)		—			(2,942	)
Change in operating assets and liabilities:						—			—
Accounts receivable, net			65,612			6,708			72,320
Other receivables			10,315			—			10,315
Income taxes receivable			(2,637	)		4,735			2,098
Inventory	ADJ 3		20,537			1,871			22,408
Prepaid expenses, other current assets and other assets			(29,883	)		(2,081	)		(31,964	)
Accounts payable			(91,907	)		—			(91,907	)
Accrued expenses and other liabilities			17,929			(6,612	)		11,317
Income taxes payable			(3,939	)		—			(3,939	)
Net cash (used in) provided by operating activities			(45,604	)		2,589			(43,015	)
Cash flows from investing activities:
Purchases of property, plant and equipment			(33,683	)		(2,654	)		(36,337	)
Purchases of intangibles - developed technology			(9,438	)		—			(9,438	)
Proceeds from sales and maturities of available-for-sale investments			10,567			—			10,567
Purchases of available-for-sale investments			(868	)		—			(868	)
Proceeds from beneficial interests in securitized accounts receivable			1,218			—			1,218
Net cash used in investing activities			(32,204	)		(2,654	)		(34,858	)
Cash flows from financing activities:
Tax withholdings related to stock-based compensation settlements			(6,458	)		—			(6,458	)
Proceeds from stock option exercises			540			—			540
Dividend payments			(21,237	)		—			(21,237	)
Proceeds from receivables purchase agreement			14,099			—			14,099
Proceeds from draw on revolving credit agreements			163,733			—			163,733
Repayment of revolving credit agreements			(64,987	)		—			(64,987	)
Redemption of redeemable non-controlling interest			(1,224	)		—			(1,224	)
Payment of debt issuance cost			(708	)		—			(708	)
Repayment of notes payable			(24,891	)		—			(24,891	)
Net cash provided by financing activities			58,867			—			58,867
Net decrease in cash and cash equivalents			(18,941	)		(65	)		(19,006	)
Effect of exchange rate changes			(2,536	)		65			(2,471	)
Cash, cash equivalents and restricted cash, beginning of year			108,644			—			108,644
Cash, cash equivalents and restricted cash, end of year		$	87,167		$	—		$	87,167
Supplemental disclosure of cash financing activities
Cash paid for interest		$	12,596		$	—		$	12,596
Cash paid for income taxes, net of refunds		$	18,552		$	—		$	18,552
Cash used in operating activities related to operating leases		$	9,682		$	—		$	9,682
Supplemental disclosure of non-cash investing activities:
Right-of-use assets obtained in exchange for lease obligations		$	17,865		$	—		$	17,865
Purchases of property, plant and equipment included in accounts payable		$	1,298		$	—		$	1,298
Redemption of redeemable non-controlling interest		$	371		$	—		$	371