Exhibit 99.1

Press Release Source: Ultra Clean Holdings, Inc.

Ultra Clean Reports Record Fourth Quarter and Full Year 2021 Financial Results

HAYWARD, Calif., February 23, 2022 /PRNewswire/ Ultra Clean Holdings, Inc. (Nasdaq: UCTT), today reported its financial results for the fourth quarter and full year ended December 31, 2021.

“Record fourth quarter performance propelled UCT over the $2 billion revenue milestone for the year and represents a strong endorsement of our execution capabilities on every level,” said Jim Scholhamer, CEO. “By expanding our capabilities, leveraging our global footprint, and deepening our industry partnerships, we again outperformed the markets we serve. We expect 2022 to be another year of growth and believe we are ideally positioned to meet ongoing demand.”

“In 2021, UCT generated record cash flow from operations and grew earnings per share by 50 percent to the highest level in the company’s history,” added Sheri Savage, CFO. "We strategically deployed capital to meet capacity requirements and will continue to invest in our business to meet ongoing demand while strengthening our balance sheet to capitalize on future growth opportunities.”

Fourth Quarter 2021 GAAP Financial Results

Total revenue was $615.1 million. Products contributed $533.8 million and Services added $81.3 million. Total gross margin was 21.0%, operating margin was 10.2%, and net income was $45.5 million or $1.01 and $1.00 per basic and diluted share. This compares to total revenue of $553.7 million, gross margin of 20.6%, operating margin of 9.1%, and net income of $31.9 million or $0.71 and $0.70 per basic and diluted share in the prior quarter.

Fourth Quarter 2021 Non-GAAP Financial Results

On a non-GAAP basis, gross margin was 21.5%, operating margin was 12.6%, and net income was $55.5 million or $1.22 per diluted share. This compares to gross margin of 21.6%, operating margin of 12.4%, and net income of $48.8 million or $1.07 per diluted share in the prior quarter.

Full Year 2021 GAAP Financial Results

Total revenue was $2,101.6 million. Products contributed $1,803.9 million and Services added $297.7 million. Total gross margin was 20.5%, operating margin was 8.8%, and net income was $119.4 million or $2.75 and $2.69 per basic and diluted share. This compares to total revenue of $1,398.6 million, gross margin of 20.9%, operating margin of 8.7%, and net income of $77.6 million or $1.93 and $1.89 per basic and diluted share in the prior year.

Full Year 2021 Non-GAAP Financial Results

On a non-GAAP basis, the company reported gross margin of 21.4%, operating margin of 12.2%, and net income of $186.1 million or $4.20 per diluted share. This compares to gross margin of 21.4%, operating margin of 11.3%, and net income of $115.0 million or $2.80 per diluted share in the prior year.

First Quarter 2022 Outlook

The Company expects revenue in the range of $580.0 million to $630.0 million and GAAP diluted net income per share to be between $0.80 and $1.00. The Company expects non-GAAP diluted net income per share to be between $1.06 and $1.26.

Conference Call

The call will take place at 1:45 p.m. PT and can be accessed by dialing 1-844-826-3034 or 1-412-317-5179. No passcode is required. A replay of the call will be available by dialing 1-877-344-7529 or 1-412-317-0088 and entering the confirmation code 3645393. The Webcast will be available on the Investor Relations section of the Company's website at http://uct.com/investors/events/.

About Ultra Clean Holdings, Inc.

Ultra Clean Holdings, Inc. is a leading developer and supplier of critical subsystems, components and parts, and ultra-high purity cleaning and analytical services primarily for the semiconductor industry. Under its Products division, UCT offers its customers an integrated outsourced solution for major subassemblies, improved design-to-delivery cycle times, design for manufacturability, prototyping, and high-precision manufacturing. Under its Services Division, UCT offers its customers tool chamber parts cleaning and coating, as well as micro-contamination analytical services. Ultra Clean is headquartered in Hayward, California. Additional information is available at www.uct.com.

Use of Non-GAAP Measures

In addition to providing results that are determined in accordance with Generally Accepted Accounting Principles in the United States of America (GAAP), management uses non-GAAP gross margin, non-GAAP operating margin and non-GAAP net income to evaluate the Company's operating and financial results. We believe the presentation of non-GAAP results is useful to investors for analyzing our core business and business trends and comparing performance to prior periods, along with enhancing investors' ability to view the Company's results from management's perspective. The presentation of this additional information should not be considered a substitute for results prepared in accordance with GAAP. Tables presenting reconciliations from GAAP results to non-GAAP results are included at the end of this press release.

The Company currently defines non-GAAP net income as net income (loss) before amortization of intangible assets, restructuring charges, executive transition costs, acquisition costs, fair value adjustments, depreciation adjustments, stock-based compensation, certain insurance proceeds, gain on sale of property and the tax effects of the foregoing adjustments.

A reconciliation of our guidance for non-GAAP net income per diluted share for the subsequent quarter is not available due to fluctuations in the geographic mix of our earnings from quarter to quarter, which impacts our tax rate and cannot be reasonably predicted or determined. As a result, such reconciliation is not available without unreasonable efforts and we are unable to determine the probable significance of the unavailable information.

Safe Harbor Statement

The foregoing information contains, or may be deemed to contain, "forward-looking statements" (as defined in the US Private Securities Litigation Reform Act of 1995) which reflect our current views with respect to future events and financial performance. We use words such as "anticipates," “projection,” “outlook,” “forecast,” "believes," "plan," "expect," "future," "intends," "may," "will," "estimates," “see,” "predicts," “should” and similar expressions to identify these forward-looking statements. Forward looking statements included in this press release include our expectations about the semiconductor capital equipment market and outlook. All forward-looking statements address matters that involve risks and uncertainties. Accordingly, the Company’s actual results may differ materially from the results predicted or implied by these forward-looking statements. These risks, uncertainties and other factors also include, among others, those identified in "Risk Factors,” "Management's Discussion and Analysis of Financial Condition and Results of Operations'' and elsewhere in our annual report on Form 10-K for the year ended December 25, 2020 as filed with the Securities and Exchange Commission. Ultra Clean Holdings, Inc. undertakes no obligation to publicly update or review any forward-looking statements, whether as a result of new information, future developments or otherwise unless required by law.

Contact:

Rhonda Bennetto

SVP Investor Relations

rbennetto@uct.com

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited; in thousands, except per share data)

	Three Months Ended						Twelve Months Ended
	December 31,			December 25,			December 31,			December 25,
	2021			2020			2021			2020
Revenues:
Product	$	533,859		$	299,495		$	1,803,939		$	1,131,151
Services		81,277			70,133			297,676			267,431
Total revenues		615,136			369,628			2,101,615			1,398,582
Cost of revenues:
Product		433,933			247,103			1,478,764			934,716
Services		52,117			44,880			192,874			172,105
Total cost of revenues		486,050			291,983			1,671,638			1,106,821
Gross profit		129,086			77,645			429,977			291,761
Operating expenses:
Research and development		7,771			3,987			24,508			14,829
Sales and marketing		14,090			6,569			48,178			25,128
General and administrative		44,493			33,915			171,618			130,434
Total operating expenses		66,354			44,471			244,304			170,391
Income from operations		62,732			33,174			185,673			121,370
Interest income		156			179			427			875
Interest expense		(6,634	)		(3,758	)		(24,183	)		(16,852	)
Other income (expense), net		(1,165	)		(2,512	)		(7,601	)		(5,722	)
Income before provision for income taxes		55,089			27,083			154,316			99,671
Provision for income taxes		6,303			4,349			27,931			19,281
Net income		48,786			22,734			126,385			80,390
Less: Net income attributable to noncontrolling interests		3,316			180			6,940			2,785
Net income attributable to UCT	$	45,470		$	22,554		$	119,445		$	77,605
Net income per share attributable to UCT common stockholders:
Basic	$	1.01		$	0.56		$	2.75		$	1.93
Diluted	$	1.00		$	0.55		$	2.69		$	1.89
Shares used in computing net income per share:
Basic		44,886			40,521			43,498			40,198
Diluted		45,525			41,353			44,351			41,074

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(Unaudited; in thousands)

	December 31,			December 25,
	2021			2020
ASSETS
Current assets:
Cash and cash equivalents	$	466,455		$	200,274
Accounts receivable, net of allowance		250,147			145,539
Inventories		379,235			180,385
Prepaid expenses and other current assets		41,260			18,895
Total current assets		1,137,097			545,093
Property, plant and equipment, net		242,347			159,150
Goodwill		270,044			171,132
Intangibles assets, net		245,696			160,519
Deferred tax assets, net		37,607			23,513
Operating lease right-of-use assets		83,357			37,821
Other non-current assets		9,242			5,315
Total assets	$	2,025,390		$	1,102,543
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Bank borrowings	$	22,071		$	7,361
Accounts payable		332,897			121,328
Accrued compensation and related benefits		46,790			34,532
Operating lease liabilities		17,299			11,721
Other current liabilities		50,060			26,335
Total current liabilities		469,117			201,277
Bank borrowings, net of current portion		529,919			261,619
Deferred tax liabilities		54,889			33,571
Operating lease liabilities		65,923			31,050
Other liabilities		12,894			23,812
Total liabilities		1,132,742			551,329
Equity:
UCT stockholders’ equity:
Common stock		511,628			309,589
Retained earnings		337,417			217,972
Accumulated other comprehensive gain (loss)		(167	)		5,087
Total UCT stockholders' equity		848,878			532,648
Noncontrolling interest		43,770			18,566
Total equity		892,648			551,214
Total liabilities and stockholders' equity	$	2,025,390		$	1,102,543

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited; in thousands)

	Fiscal Year Ended
	December 31,			December 25,
	2021			2020
Cash flows from operating activities:
Net income	$	126,385		$	80,390
Adjustments to reconcile net income to net cash provided by operating activities (excluding assets acquired and liabilities assumed):
Depreciation and amortization		70,877			46,635
Stock-based compensation		15,765			12,743
Deferred income taxes		(3,200	)		375
Change in the fair value of financial instruments and earn-out liability		12,438			7,653
Gain from insurance proceeds		(7,332	)		—
Others		220			(2,402	)
Changes in assets and liabilities:
Accounts receivable		(52,975	)		(32,693	)
Inventories		(125,120	)		(8,017	)
Prepaid expenses and other current assets		(3,397	)		1,243
Other non-current assets		(800	)		(106	)
Accounts payable		172,524			(12,559	)
Accrued compensation and related benefits		1,795			9,696
Operating lease assets and liabilities		(1,141	)		(1,111	)
Income taxes payable		8,851			2,785
Other liabilities		(1,827	)		(7,354	)
Net cash provided by operating activities		213,063			97,278
Cash flows from investing activities:
Purchases of property, plant and equipment		(59,342	)		(36,427	)
Proceeds from sale of property and equipment, including insurance proceeds		7,738			6,601
Settlement of forward contracts in conjunction with the acquisition of Ham-Let		(10,448	)		—
Acquisition of business, net of cash acquired		(344,707	)		—
Net cash used in investing activities		(406,759	)		(29,826	)
Cash flows from financing activities:
Proceeds from bank borrowings		415,168			76,690
Proceeds from issuance of common stock		193,536			604
Payments on bank borrowings and finance leases		(131,712	)		(105,475	)
Payments of debt issuance costs		(8,899	)		—
Payment of contingent earn-out		—			(1,428	)
Employees’ taxes paid upon vesting of restricted stock units		(7,262	)		(1,500	)
Net cash provided by (used in) financing activities		460,831			(31,109	)
Effect of exchange rate changes on cash and cash equivalents		(954	)		1,400
Net increase in cash and cash equivalents		266,181			37,743
Cash and cash equivalents at beginning of period		200,274			162,531
Cash and cash equivalents at end of period	$	466,455		$	200,274

ULTRA CLEAN HOLDINGS, INC.

REPORTABLE SEGMENTS

GAAP TO NON-GAAP RECONCILIATION

(Unaudited; dollars in thousands)

	GAAP						Non-GAAP
	Three Months Ended						Three Months Ended
	December 31, 2021						December 31, 2021
	Products		Services		Consolidated		Products		Services		Consolidated
Revenues	$	533,859	$	81,277	$	615,136	$	533,859	$	81,277	$	615,136
Gross profit	$	99,926	$	29,160	$	129,086	$	101,964	$	30,183	$	132,147
Gross margin		18.7%		35.9%		21.0%		19.1%		37.1%		21.5%
Income from operations	$	52,391	$	10,341	$	62,732	$	63,007	$	14,507	$	77,514
Operating margin		9.8%		12.7%		10.2%		11.8%		17.9%		12.6%

	Three Months Ended
	December 31, 2021
	Products		Services			Consolidated
Reconciliation of GAAP Gross profit to Non-GAAP Gross profit (in thousands)
Reported gross profit on a GAAP basis	$	99,926	$	29,160		$	129,086
Amortization of intangible assets (1)		658		1,023			1,681
Restructuring charges (2)		115		—			115
Stock-based compensation expense (3)		719		—			719
Fair value related adjustments (4)		546		—			546
Non-GAAP gross profit	$	101,964	$	30,183		$	132,147
Reconciliation of GAAP Gross margin to Non-GAAP Gross margin
Reported gross margin on a GAAP basis		18.7%		35.9%			21.0%
Amortization of intangible assets (1)		0.1%		1.2%			0.3%
Restructuring charges (2)		0.0%		—			0.0%
Stock-based compensation expense (3)		0.2%		—			0.1%
Fair value related adjustments (4)		0.1%		—			0.1%
Non-GAAP gross margin		19.1%		37.1	%		21.5%
Reconciliation of GAAP Income from operations to Non-GAAP Income from operations (in thousands)
Reported income from operations on a GAAP basis	$	52,391	$	10,341		$	62,732
Amortization of intangible assets (1)		5,795		3,716			9,511
Restructuring charges (2)		(415		24			(391	)
Stock-based compensation expense (3)		4,241		426			4,667
Fair value related adjustments (4)		546		—			546
Acquisition related costs (5)		449		—			449
Non-GAAP income from operations	$	63,007	$	14,507		$	77,514
Reconciliation of GAAP Operating margin to Non-GAAP Operating margin
Reported operating margin on a GAAP basis		9.8%		12.7%			10.2%
Amortization of intangible assets (1)		1.1%		4.6%			1.5%
Restructuring charges (2)		-0.1%		0.1%			-0.1%
Stock-based compensation expense (3)		0.8%		0.5%			0.8%
Fair value related adjustments (4)		0.1%		0.0%			0.1%
Acquisition related costs (5)		0.1%		0.0%			0.1%
Non-GAAP operating margin		11.8%		17.9%			12.6%

1	Amortization of intangible assets related to the Company's business acquisitions
2	Represents severance, retention and costs related to facility closures
3	Represents compensation expense for stock granted to employees and directors
4	Represents acquisition fair value adjustments related to inventories
5	Represents costs related to the acquisition of Ham-Let

ULTRA CLEAN HOLDINGS, INC.

UNAUDITED RECONCILIATION OF GAAP TO NON-GAAP ADJUSTED RESULTS

	Three Months Ended									Twelve Months Ended
	December 31,			December 25,			September 24,			December 31,			December 25,
	2021			2020			2021			2021			2020
Reconciliation of GAAP Net Income to Non-GAAP Net Income (in thousands)
Reported net income attributable to UCT on a GAAP basis	$	45,470		$	22,554		$	31,880		$	119,445		$	77,605
Amortization of intangible assets (1)		9,511			4,950			9,512			33,423			19,799
Restructuring charges (2)		(391	)		1,003			1,580			1,301			4,573
Stock-based compensation expense (3)		4,667			3,760			4,324			16,758			12,899
Fair value related adjustments (4)		546			3,266			2,288			22,999			7,624
Acquisition related costs (5)		449			1,024			105			9,984			1,024
Insurance proceeds (6)		—			—			—			(7,332	)		—
Gain on the sale of property (7)		—			—			—			—			(1,352	)
Income tax effect of non-GAAP adjustments (8)		(2,336	)		(2,521	)		(2,760	)		(12,804	)		(8,200	)
Income tax effect of valuation allowance (9)		(2,400	)		(525	)		1,828			2,332			994
Non-GAAP net income attributable to UCT	$	55,516		$	33,511		$	48,757		$	186,106		$	114,966
Reconciliation of GAAP Income from operations to Non-GAAP Income from operations (in thousands)
Reported income from operations on a GAAP basis	$	62,732		$	33,174		$	50,584		$	185,673		$	121,370
Amortization of intangible assets (1)		9,511			4,950			9,512			33,423			19,799
Restructuring charges (2)		(391	)		1,003			1,580			1,301			4,433
Stock-based compensation expense (3)		4,667			3,760			4,324			16,758			12,899
Fair value related adjustments (4)		546			—			2,388			10,117			—
Acquisition related costs (5)		449			1,024			105			9,984			1,024
Gain on the sale of property (7)		—			—			—			—			(1,352	)
Non-GAAP income from operations	$	77,514		$	43,911		$	68,493		$	257,256		$	158,173
Reconciliation of GAAP Operating margin to Non-GAAP Operating margin
Reported operating margin on a GAAP basis		10.2	%		9.0	%		9.1	%		8.8	%		8.7	%
Amortization of intangible assets (1)		1.5	%		1.3	%		1.7	%		1.6	%		1.4	%
Restructuring charges (2)		-0.1	%		0.3	%		0.4	%		0.0	%		0.3	%
Stock-based compensation expense (3)		0.8	%		1.0	%		0.8	%		0.8	%		0.9	%
Fair value related adjustments (4)		0.1	%		0.0	%		0.4	%		0.5	%		0.0	%
Acquisition related costs (5)		0.1	%		0.3	%		0.0	%		0.5	%		0.1	%
Gain on the sale of property (7)		0.0	%		0.0	%		0.0	%		0.0	%		-0.1	%
Non-GAAP operating margin		12.6	%		11.9	%		12.4	%		12.2	%		11.3	%
Reconciliation of GAAP Gross profit to Non-GAAP Gross profit (in thousands)
Reported gross profit on a GAAP basis	$	129,086		$	77,645		$	114,070		$	429,977		$	291,761
Amortization of intangible assets (1)		1,681			1,023			1,680			6,063			4,090
Restructuring charges (2)		115			242			684			1,005			988
Stock-based compensation expense (3)		719			696			534			2,649			2,112
Fair value related adjustments (4)		546			—			2,388			10,117			—
Non-GAAP gross profit	$	132,147		$	79,606		$	119,356		$	449,811		$	298,951
Reconciliation of GAAP Gross margin to Non-GAAP Gross margin
Reported gross margin on a GAAP basis		21.0	%		21.0	%		20.6	%		20.5	%		20.9	%
Amortization of intangible assets (1)		0.3	%		0.3	%		0.3	%		0.3	%		0.3	%
Restructuring charges (2)		0.0	%		0.0	%		0.2	%		0.0	%		0.0	%
Stock-based compensation expense (3)		0.1	%		0.2	%		0.1	%		0.1	%		0.2	%
Fair value related adjustments (4)		0.1	%		0.0	%		0.4	%		0.5	%		0.0	%
Non-GAAP gross margin		21.5	%		21.5	%		21.6	%		21.4	%		21.4	%

Reconciliation of GAAP Interest and other income (expense) to Non-GAAP Interest and other income (expense) (in thousands)
Reported interest and other income (expense) on a GAAP basis	$	(7,643	)	$	(6,091	)	$	(8,233	)	$	(31,357	)	$	(21,699	)
Restructuring charges (2)		—			—			—			—			140
Fair value related adjustments (4)		—			3,266			(100	)		12,882			7,624
Insurance proceeds (6)		—			—			—			(7,332	)		—
Non-GAAP interest and other income (expense)	$	(7,643	)	$	(2,825	)	$	(8,333	)	$	(25,807	)	$	(13,935	)
Reconciliation of GAAP Earnings Per Diluted Share to Non-GAAP Earnings Per Diluted Share
Reported net income on a GAAP basis	$	1.00		$	0.55		$	0.70			2.69			1.89
Amortization of intangible assets (1)		0.21			0.12			0.21			0.75			0.48
Restructuring charges (2)		(0.01	)		0.02			0.03			0.03			0.11
Stock-based compensation expense (3)		0.10			0.09			0.10			0.38			0.32
Fair value related adjustments (4)		0.01			0.08			0.05			0.52			0.19
Acquisition related costs (5)		0.01			0.02			—			0.23			0.02
Insurance proceeds (6)		—			—			—			(0.16	)		—
Gain on the sale of property (7)		—			—			—			—			(0.03	)
Income tax effect of non-GAAP adjustments (8)		(0.05	)		(0.06	)		(0.06	)		(0.29	)		(0.20	)
Income tax effect of valuation allowance (9)		(0.05	)		(0.01	)		0.04			0.05			0.02
Non-GAAP net income	$	1.22		$	0.81		$	1.07		$	4.20		$	2.80
Weighted average number of diluted shares (thousands) on a non-GAAP basis		45,525			41,353			45,404			44,351			41,074

ULTRA CLEAN HOLDINGS, INC.

UNAUDITED RECONCILIATION OF GAAP TO NON-GAAP EFFECTIVE INCOME TAX RATE

	Three Months Ended								Twelve Months Ended
	December 31,			December 25,		September 24,			December 31,			December 25,
	2021			2020		2021			2021			2020
(in thousands, except percentages)
Provision for income taxes on a GAAP basis	$	6,303		$	4,349	$	8,392			27,931			19,281
Income tax effect of non-GAAP adjustments (8)		2,336			2,521		2,760			12,804			8,200
Income tax effect of valuation allowance (9)		2,400			525		(1,828	)		(2,332	)		(994	)
Non-GAAP provision for income taxes	$	11,039		$	7,395	$	9,324		$	38,403		$	26,487
Income before income taxes on a GAAP basis	$	55,089		$	27,083	$	42,351			154,316			99,671
Amortization of intangible assets (1)		9,511			4,950		9,512			33,423			19,799
Restructuring charges (2)		(391	)		1,003		1,580			1,301			4,573
Stock-based compensation expense (3)		4,667			3,760		4,324			16,758			12,899
Fair value related adjustments (4)		546			3,266		2,288			22,999			7,624
Acquisition related costs (5)		449			1,024		105			9,984			1,024
Insurance proceeds (6)		—			—		—			(7,332	)		—
Gain on the sale of property (7)		—			—		(100	)		—			(1,352	)
Non-GAAP income before income taxes	$	69,871		$	41,086	$	60,060		$	231,449		$	144,238
Effective income tax rate on a GAAP basis		11.4%			16.1%		19.8%			18.1%			19.3%
Non-GAAP effective income tax rate		15.8%			18.0%		15.5%			16.6%			18.4%

1 Amortization of intangible assets related to the Company's business acquisitions

2 Represents severance, retention and costs related to facility closures

3 Represents compensation expense for stock granted to employees and directors

4 Adjustments related to the fair values of inventories, contingent consideration, purchase obligation and forward hedge contracts

5 Represents costs related to acquisitions

6 Insurance proceeds pertaining to the Cinos fire in 2018

7 Represents gain realized on the sale of land in South Korea

8 Tax effect of items (1) through (7) above based on the non-GAAP tax rate

9 The Company's GAAP tax expense is generally higher than the Company's non-GAAP tax expense, primarily due to losses in the U.S. with full federal and state valuation allowances. The Company's non-GAAP tax rate and resulting non-GAAP tax expense considers the tax implications as if there was no federal or state valuation allowance position in effect.