Illumina (ILMN) 10-Q9 Nov 232023 Q3 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares shares in Millions	9 Months Ended
Cover Page - shares shares in Millions	Oct. 01, 2023	Nov. 06, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Oct. 01, 2023
Document Transition Report	false
Entity File Number	001-35406
Entity Registrant Name	Illumina, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0804655
Entity Address, Address Line One	5200 Illumina Way
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92122
City Area Code	858
Local Phone Number	202-4500
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	ILMN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		158.8
Entity Central Index Key	0001110803
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Oct. 01, 2023	Jan. 01, 2023
Current assets:
Cash and cash equivalents	$ 927	$ 2,011
Short-term investments	6	26
Accounts receivable, net	690	671
Inventory, net	615	568
Prepaid expenses and other current assets	268	285
Total current assets	2,506	3,561
Property and equipment, net	1,040	1,091
Operating lease right-of-use assets	581	653
Goodwill	2,527	3,239
Intangible assets, net	3,029	3,285
Other assets	439	423
Total assets	10,122	12,252
Current liabilities:
Accounts payable	240	293
Accrued liabilities	1,242	1,232
Term notes, current portion	0	500
Convertible senior notes, current portion	0	748
Total current liabilities	1,482	2,773
Operating lease liabilities	698	744
Term notes	1,489	1,487
Other long-term liabilities	555	649
Stockholders’ equity:
Common stock	2	2
Additional paid-in capital	9,487	9,207
Accumulated other comprehensive income	21	3
Retained earnings	157	1,142
Treasury stock, at cost	(3,769)	(3,755)
Total stockholders’ equity	5,898	6,599
Total liabilities and stockholders’ equity	$ 10,122	$ 12,252

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Revenue:
Total revenue	$ 1,119	$ 1,115	$ 3,382	$ 3,501
Cost of revenue:
Amortization of acquired intangible assets	47	46	143	125
Total cost of revenue	435	398	1,312	1,201
Gross profit	684	717	2,070	2,300
Operating expense:
Research and development	315	325	1,013	975
Selling, general and administrative	303	146	1,127	865
Goodwill and intangible impairment	821	3,914	821	3,914
Legal contingency and settlement	(1)	(11)	14	598
Total operating expense	1,438	4,374	2,975	6,352
Loss from operations	(754)	(3,657)	(905)	(4,052)
Other income (expense):
Interest income	13	3	47	4
Interest expense	(19)	(6)	(59)	(17)
Other expense, net	(22)	(12)	(33)	(103)
Total other expense, net	(28)	(15)	(45)	(116)
Loss before income taxes	(782)	(3,672)	(950)	(4,168)
(Benefit) provision for income taxes	(28)	144	36	97
Net loss	$ (754)	$ (3,816)	$ (986)	$ (4,265)
Loss per share:
Basic (in dollars per share)	$ (4.77)	$ (24.26)	$ (6.23)	$ (27.13)
Diluted (in dollars per share)	$ (4.77)	$ (24.26)	$ (6.23)	$ (27.13)
Shares used in computing loss per share:
Basic (in shares)	158	157	158	157
Diluted (in shares)	158	157	158	157
Product revenue
Revenue:
Total revenue	$ 941	$ 963	$ 2,864	$ 3,039
Cost of revenue:
Cost of revenue	293	280	884	866
Service and other revenue
Revenue:
Total revenue	178	152	518	462
Cost of revenue:
Cost of revenue	$ 95	$ 72	$ 285	$ 210

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (754)	$ (3,816)	$ (986)	$ (4,265)
Unrealized gain on cash flow hedges, net of deferred tax	9	9	18	22
Total comprehensive loss	$ (745)	$ (3,807)	$ (968)	$ (4,243)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) shares in Millions, $ in Millions	Total	Cumulative-effect adjustment from adoption of ASU 2016-02, net of deferred tax	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative-effect adjustment from adoption of ASU 2016-02, net of deferred tax	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Retained Earnings Cumulative-effect adjustment from adoption of ASU 2016-02, net of deferred tax	Treasury Stock
Beginning Balance (in shares) at Jan. 02, 2022			197
Beginning balance (in shares) at Jan. 02, 2022									(40)
Beginning balance at Jan. 02, 2022	$ 10,740	$ (32)	$ 2	$ 8,938	$ (93)	$ 17	$ 5,485	$ 61	$ (3,702)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	86						86
Unrealized gain (loss) on cash flow hedges, net of deferred tax	1					1
Issuance of common stock, net of repurchases	21			33					$ (12)
Share-based compensation	79			79
Ending Balance (in shares) at Apr. 03, 2022			197
Ending balance (in shares) at Apr. 03, 2022									(40)
Ending balance at Apr. 03, 2022	$ 10,895		$ 2	8,957		18	5,632		$ (3,714)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2020-06 [Member]
Beginning Balance (in shares) at Jan. 02, 2022			197
Beginning balance (in shares) at Jan. 02, 2022									(40)
Beginning balance at Jan. 02, 2022	$ 10,740	$ (32)	$ 2	8,938	$ (93)	17	5,485	$ 61	$ (3,702)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(4,265)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	22
Ending Balance (in shares) at Oct. 02, 2022			197
Ending balance (in shares) at Oct. 02, 2022									(40)
Ending balance at Oct. 02, 2022	6,731		$ 2	9,129		39	1,281		$ (3,720)
Beginning Balance (in shares) at Apr. 03, 2022			197
Beginning balance (in shares) at Apr. 03, 2022									(40)
Beginning balance at Apr. 03, 2022	10,895		$ 2	8,957		18	5,632		$ (3,714)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(535)						(535)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	12					12
Issuance of common stock, net of repurchases	(4)								$ (4)
Share-based compensation	76			76
Ending Balance (in shares) at Jul. 03, 2022			197
Ending balance (in shares) at Jul. 03, 2022									(40)
Ending balance at Jul. 03, 2022	10,444		$ 2	9,033		30	5,097		$ (3,718)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(3,816)						(3,816)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	9					9
Issuance of common stock, net of repurchases	28			30					$ (2)
Share-based compensation	66			66
Ending Balance (in shares) at Oct. 02, 2022			197
Ending balance (in shares) at Oct. 02, 2022									(40)
Ending balance at Oct. 02, 2022	6,731		$ 2	9,129		39	1,281		$ (3,720)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(139)						(139)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	(36)					(36)
Issuance of common stock, net of repurchases (in shares)			1
Issuance of common stock, net of repurchases	(35)								$ (35)
Share-based compensation	78			78
Ending Balance (in shares) at Jan. 01, 2023			198
Ending balance (in shares) at Jan. 01, 2023									(40)
Ending balance at Jan. 01, 2023	6,599		$ 2	9,207		3	1,142		$ (3,755)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3						3
Unrealized gain (loss) on cash flow hedges, net of deferred tax	(4)					(4)
Issuance of common stock, net of repurchases	28			37					$ (9)
Share-based compensation	67			67
Ending Balance (in shares) at Apr. 02, 2023			198
Ending balance (in shares) at Apr. 02, 2023									(40)
Ending balance at Apr. 02, 2023	6,693		$ 2	9,311		(1)	1,145		$ (3,764)
Beginning Balance (in shares) at Jan. 01, 2023			198
Beginning balance (in shares) at Jan. 01, 2023									(40)
Beginning balance at Jan. 01, 2023	6,599		$ 2	9,207		3	1,142		$ (3,755)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(986)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	18
Ending Balance (in shares) at Oct. 01, 2023			198
Ending balance (in shares) at Oct. 01, 2023									(40)
Ending balance at Oct. 01, 2023	5,898		$ 2	9,487		21	157		$ (3,769)
Beginning Balance (in shares) at Apr. 02, 2023			198
Beginning balance (in shares) at Apr. 02, 2023									(40)
Beginning balance at Apr. 02, 2023	6,693		$ 2	9,311		(1)	1,145		$ (3,764)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(234)						(234)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	13					13
Issuance of common stock, net of repurchases	(3)			0					$ (3)
Share-based compensation	77			77
Reclassification of liability-classified awards	9			9
Ending Balance (in shares) at Jul. 02, 2023			198
Ending balance (in shares) at Jul. 02, 2023									(40)
Ending balance at Jul. 02, 2023	6,555		$ 2	9,397		12	911		$ (3,767)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(754)						(754)
Unrealized gain (loss) on cash flow hedges, net of deferred tax	9					9
Issuance of common stock, net of repurchases	28			30					$ (2)
Share-based compensation	60			60
Ending Balance (in shares) at Oct. 01, 2023			198
Ending balance (in shares) at Oct. 01, 2023									(40)
Ending balance at Oct. 01, 2023	$ 5,898		$ 2	$ 9,487		$ 21	$ 157		$ (3,769)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022
Cash flows from operating activities:
Net loss	$ (986)	$ (4,265)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation expense	175	158
Amortization of intangible assets	148	130
Share-based compensation expense	286	266
Deferred income taxes	(42)	(40)
Goodwill and intangible (IPR&D) impairment	821	3,914
Property and equipment and right-of-use asset impairment	56	0
Net losses on strategic investments	39	79
(Gain) loss on Helix contingent value right	(8)	8
Payment of accreted debt discount	(15)	0
Change in fair value of contingent consideration liabilities	(82)	(230)
Unrealized loss on foreign exchange translation	21	1
Other	9	6
Changes in operating assets and liabilities:
Accounts receivable	(31)	13
Inventory	(47)	(127)
Prepaid expenses and other current assets	(3)	10
Operating lease right-of-use assets and liabilities, net	(13)	(10)
Other assets	6	17
Accounts payable	(50)	(51)
Accrued liabilities	(25)	388
Other long-term liabilities	(5)	(22)
Net cash provided by operating activities	254	245
Cash flows from investing activities:
Purchases of property and equipment	(144)	(198)
Purchases of strategic investments	(19)	(26)
Sales of strategic investments	18	0
Net cash paid for acquisitions	0	(85)
Cash paid for intangible asset	(1)	(180)
Net cash used in investing activities	(146)	(489)
Cash flows from financing activities:
Debt issuance costs paid for credit facility	(1)	0
Payments on financing obligations	(1,235)	0
Taxes paid related to net share settlement of equity awards	(14)	(19)
Proceeds from issuance of common stock	67	63
Net cash (used in) provided by financing activities	(1,183)	44
Effect of exchange rate changes on cash and cash equivalents	(9)	(32)
Net decrease in cash and cash equivalents	(1,084)	(232)
Cash and cash equivalents at beginning of period	2,011	1,232
Cash and cash equivalents at end of period	$ 927	$ 1,000

Organization and Significant Ac

Organization and Significant Accounting Policies	9 Months Ended
Organization and Significant Accounting Policies	Oct. 01, 2023
Accounting Policies [Abstract]
Organization and Significant Accounting Policies	1. ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES Business Overview We are a provider of sequencing- and array-based solutions, serving customers in the research, clinical and applied markets. Our products are used for applications in the life sciences, oncology, reproductive health, agriculture and other emerging segments. Our customers include leading genomic research centers, academic institutions, government laboratories, and hospitals, as well as pharmaceutical, biotechnology, commercial molecular diagnostic laboratories, and consumer genomics companies . On August 18, 2021, we acquired GRAIL, a healthcare company focused on early detection of multiple cancers. The acquisition is subject to ongoing legal proceedings and, currently, GRAIL must be held and operated separately and independently from Illumina pursuant to the transitional measures ordered by the European Commission in the EC Divestment Decision, following the prohibition of our acquisition of GRAIL on September 6, 2022. Refer to note “ 7. Legal Proceedings ” for additional details. GRAIL is a separate reportable segment. With respect to GRAIL, we have retained advisors and are preparing for sale and capital markets transaction options in accordance with the European Commission’s divestiture order. In parallel, ongoing appeals preserve flexibility for any divestiture of GRAIL and future transactions. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Interim financial results are not necessarily indicative of results anticipated for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and footnotes included in the Annual Report on Form 10-K for the fiscal year ended January 1, 2023, from which the prior year balance sheet information herein was derived. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue, and expense, and related disclosure of contingent assets and liabilities. Though the COVID-19 pandemic, the armed conflict between Russia and Ukraine, and macroeconomic factors such as inflation, exchange rates and concerns about an economic downturn present additional uncertainty, we continue to use the best information available to form our critical accounting estimates. Actual results could differ from those estimates. The unaudited condensed consolidated financial statements include our accounts, our wholly-owned subsidiaries, and majority-owned or controlled companies. All intercompany transactions and balances have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. In management’s opinion, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, considered necessary for a fair presentation of the results for the interim periods presented. Fiscal Year Our fiscal year is the 52 or 53 weeks ending the Sunday closest to December 31, with quarters of 13 or 14 weeks ending the Sunday closest to March 31, June 30, September 30, and December 31. References to Q3 2023 and Q3 2022 refer to the three months ended October 1, 2023 and October 2, 2022, respectively, which were both 13 weeks, and references to year-to-date (YTD) 2023 and 2022 refer to the nine months ended October 1, 2023 and October 2, 2022, respectively, which were both 39 weeks. Significant Accounting Policies During YTD 2023, there were no changes to our significant accounting policies as described in our Annual Report on Form 10-K for the fiscal year ended January 1, 2023, with the exception of the following for income taxes: Historically, we calculated the provision/(benefit) for income taxes for interim periods utilizing an estimated annual effective tax rate applied to the income/(loss) for the reporting period, except in Q2 2023 when a year-to-date effective tax rate method was utilized. We determined the estimated annual effective tax rate method would provide a more reliable estimate of the provision for income taxes for Q3 2023 and YTD 2023 since minor changes in the estimated income/(loss) before income taxes would not result in significant changes in the estimated annual effective tax rate. Loss per Share Basic loss per share is computed based on the weighted average number of common shares outstanding during the period. Diluted loss per share is computed based on the sum of the weighted average number of common shares and potentially dilutive common shares outstanding during the period. In loss periods, basic and diluted loss per share are identical since the effect of potentially dilutive common shares is antidilutive and therefore excluded. Potentially dilutive common shares consist of shares issuable under convertible senior notes and equity awards. We utilize the if-converted method to calculate the impact of convertible senior notes on diluted loss per share. Potentially dilutive common shares from equity awards are determined using the average share price for each period under the treasury stock method. In addition, proceeds from exercise of equity awards and the average amount of unrecognized compensation expense for equity awards are assumed to be used to repurchase shares. The following table presents the weighted average shares used to calculate basic and diluted loss per share: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Weighted average shares used in calculating basic loss per share 158 157 158 157 Weighted average shares used in calculating diluted loss per share 158 157 158 157 Antidilutive shares: Convertible senior notes 1 2 1 2 Equity awards 3 2 3 2 Potentially dilutive shares excluded from calculation due to antidilutive effect 4 4 4 4

Revenue

Revenue	9 Months Ended
Revenue	Oct. 01, 2023
Revenue from Contract with Customer [Abstract]
Revenue	2. REVENUE Our revenue is generated primarily from the sale of products and services. Product revenue primarily consists of sales of instruments and consumables used in genetic analysis. Service and other revenue primarily consists of revenue generated from genotyping and sequencing services, instrument service contracts, development and licensing agreements, and cancer detection testing services related to the GRAIL business. Revenue by Source Q3 2023 Q3 2022 In millions Sequencing Microarray Total Sequencing Microarray Total Consumables $ 689 $ 71 $ 760 $ 720 $ 76 $ 796 Instruments 178 3 181 162 5 167 Total product revenue 867 74 941 882 81 963 Service and other revenue 162 16 178 133 19 152 Total revenue $ 1,029 $ 90 $ 1,119 $ 1,015 $ 100 $ 1,115 YTD 2023 YTD 2022 In millions Sequencing Microarray Total Sequencing Microarray Total Consumables $ 2,108 $ 219 $ 2,327 $ 2,237 $ 225 $ 2,462 Instruments 524 13 537 563 14 577 Total product revenue 2,632 232 2,864 2,800 239 3,039 Service and other revenue 456 62 518 390 72 462 Total revenue $ 3,088 $ 294 $ 3,382 $ 3,190 $ 311 $ 3,501 Revenue by Geographic Area Based on region of destination (in millions) Q3 2023 Q3 2022 (1) YTD 2023 YTD 2022 (1) Americas $ 663 $ 597 $ 1,920 $ 1,885 Europe 260 259 825 819 Greater China (2) 98 133 302 378 Asia-Pacific, Middle East, and Africa (3) 98 126 335 419 Total revenue $ 1,119 $ 1,115 $ 3,382 $ 3,501 _____________ (1) We implemented a new global commercial structure in Q1 2023 to improve operating efficiencies and better align with local markets. We integrated Asia-Pacific and Japan with emerging markets across the Middle East, Africa, Turkey, and Commonwealth of Independent States (CIS). Beginning in Q1 2023, and going forward, we will report regional results for the following regions: Americas, Europe, Greater China, and Asia-Pacific, Middle East and Africa (AMEA). Prior period amounts have been reclassified to conform to this new presentation. (2) Region includes revenue from China, Taiwan, and Hong Kong. (3) Region includes revenue from Russia and Turkey. Performance Obligations We regularly enter into contracts with multiple performance obligations. These contracts are believed to be firm as of the balance sheet date. However, we may allow customers to make product substitutions as we launch new products. The timing of shipments depends on several factors, including agreed upon shipping schedules, which may span multiple quarters. Most performance obligations are generally satisfied within a short time frame, approximately three Contract Assets and Liabilities Contract assets, which consist of revenue recognized and performance obligations satisfied or partially satisfied in advance of customer billing, were $19 million and $17 million as of October 1, 2023 and January 1, 2023, respectively, and were recorded in prepaid expenses and other current assets. Contract liabilities, which consist of deferred revenue and customer deposits, as of October 1, 2023 and January 1, 2023 were $315 million and $308 million, respectively, of which the short-term portions of $242 million and $245 million, respectively, were recorded in accrued liabilities and the remaining long-term portions were recorded in other long-term liabilities. Revenue recorded in Q3 2023 and YTD 2023 included $43 million and $206 million, respectively, of previously deferred revenue that was included in contract liabilities as of January 1, 2023.

Investments and Fair Value Meas

Investments and Fair Value Measurements	9 Months Ended
Investments and Fair Value Measurements	Oct. 01, 2023
Fair Value Disclosures [Abstract]
Investments and Fair Value Measurements	3. INVESTMENTS AND FAIR VALUE MEASUREMENTS Strategic Investments Marketable Equity Securities Our short-term investments consist of marketable equity securities. As of October 1, 2023 and January 1, 2023, the fair value of our marketable equity securities totaled $6 million and $26 million, respectively. Gains and losses recognized in other expense, net on our marketable equity securities were as follows: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Net gains (losses) recognized during the period on marketable equity securities $ — $ 3 $ (2) $ (66) Less: Net losses recognized during the period on marketable equity securities sold during the period — — (2) — Net unrealized gains (losses) recognized during the period on marketable equity securities still held at the reporting date $ — $ 3 $ — $ (66) Non-Marketable Equity Securities As of October 1, 2023 and January 1, 2023, the aggregate carrying amounts of our non-marketable equity securities without readily determinable fair values, included in other assets, were $28 million. Revenue recognized from transactions with our strategic investees was $2 million and $68 million for Q3 2023 and YTD 2023, respectively, and $27 million and $83 million for Q3 2022 and YTD 2022, respectively. Venture Funds We invest in two venture capital investment funds (the Funds) with capital commitments of $100 million, callable through April 2026, and up to $150 million, callable through July 2029, respectively, of which $5 million and up to $74 million, respectively, remained callable as of October 1, 2023. Our investments in the Funds are accounted for as equity-method investments. The aggregate carrying amounts of the Funds, included in other assets, were $165 million and $183 million as of October 1, 2023 and January 1, 2023, respectively. We recorded unrealized losses of $19 million and $33 million in Q3 2023 and YTD 2023, respectively, and unrealized losses of $5 million and $11 million in Q3 2022 and YTD 2022, respectively, in other expense, net. Helix Contingent Value Right In conjunction with the deconsolidation of Helix Holdings I, LLC (Helix) in April 2019, we received a contingent value right with a 7-year term that entitles us to consideration dependent upon the outcome of Helix’s future financing and/or liquidity events. Changes in the fair value of our contingent value right resulted in unrealized gains of $5 million and $8 million in Q3 2023 and YTD 2023, respectively, and unrealized losses of $5 million and $8 million in Q3 2022 and YTD 2022, respectively, which were included in other expense, net. Fair Value Measurements The following table presents the hierarchy for assets and liabilities measured at fair value on a recurring basis: October 1, 2023 January 1, 2023 In millions Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Money market funds (cash equivalents) $ 646 $ — $ — $ 646 $ 1,642 $ — $ — $ 1,642 Marketable equity securities 6 — — 6 26 — — 26 Helix contingent value right — — 66 66 — — 58 58 Deferred compensation plan assets — 57 — 57 — 52 — 52 Total assets measured at fair value $ 652 $ 57 $ 66 $ 775 $ 1,668 $ 52 $ 58 $ 1,778 Liabilities: Contingent consideration liabilities $ — $ — $ 330 $ 330 $ — $ — $ 412 $ 412 Deferred compensation plan liability — 54 — 54 — 51 — 51 Total liabilities measured at fair value $ — $ 54 $ 330 $ 384 $ — $ 51 $ 412 $ 463 Our marketable equity securities are measured at fair value based on quoted trade prices in active markets. Our deferred compensation plan assets consist primarily of investments in life insurance contracts carried at cash surrender value, which reflects the net asset value of the underlying publicly traded mutual funds. We perform control procedures to corroborate the fair value of our holdings, including comparing valuations obtained from our investment service provider to valuations reported by our asset custodians, validating pricing sources and models, and reviewing key model inputs, if necessary. We elected the fair value option to measure the contingent value right received from Helix. The fair value of such contingent value right, included in other assets, is derived using a Monte Carlo simulation. Estimates and assumptions used in the Monte Carlo simulation include probabilities related to the timing and outcome of future financing and/or liquidity events, assumptions regarding collectibility and volatility, and an estimated equity value of Helix. These unobservable inputs represent a Level 3 measurement because they are supported by little or no market activity and reflect our own assumptions in measuring fair value. We reassess the fair value of contingent consideration related to acquisitions on a quarterly basis. Changes in the fair value of contingent consideration subsequent to the acquisition date are recognized in selling, general and administrative expense. The contingent value rights issued as part of the GRAIL acquisition entitle the holders to receive future cash payments on a quarterly basis (Covered Revenue Payments) representing a pro rata portion of certain GRAIL-related revenues (Covered Revenues) each year for a 12-year period. As defined in the Contingent Value Rights Agreement , this will reflect a 2.5% payment right to the first $1 billion of revenue each year for 12 years. Revenue above $1 billion each year will be subject to a 9% contingent payment right during this same period. Covered Revenues for Q4 2022, Q1 2023, and Q2 2023 were $65 million in aggregate and Covered Revenues for Q4 2021, Q1 2022, and Q2 2022 were $32 million in aggregate, driven primarily by sales of GRAIL’s Galleri test. Covered Revenue Payments relating to such periods were approximately $609,000 and $297,000 in YTD 2023 and YTD 2022, respectively. Pursuant to the Contingent Value Rights Agreement, a portion of the Covered Revenue Payments in YTD 2022 were applied to reimburse us for certain expenses. We use a Monte Carlo simulation to estimate the fair value of contingent consideration related to the GRAIL acquisition. Estimates and assumptions used in the Monte Carlo simulation include forecasted revenues for GRAIL, a revenue risk premium, a revenue volatility estimate, an operational leverage ratio and a counterparty credit spread. These unobservable inputs represent a Level 3 measurement because they are supported by little or no market activity and reflect our own assumptions in measuring fair value. The fair value of our contingent consideration liability related to GRAIL was $330 million and $412 million as of October 1, 2023 and January 1, 2023, respectively, of which $329 million and $411 million, respectively, was included in other long-term liabilities, with the remaining balances included in accrued liabilities. Changes in the estimated fair value of our contingent consideration liabilities during YTD 2023 were as follows: In millions Balance as of January 1, 2023 $ 412 Change in estimated fair value (82) Balance as of October 1, 2023 $ 330

Debt

Debt	9 Months Ended
Debt	Oct. 01, 2023
Debt Disclosure [Abstract]
Debt	4. DEBT Summary of Term Debt Obligations In millions October 1, January 1, Principal amount of 2031 Term Notes outstanding $ 500 $ 500 Principal amount of 2027 Term Notes outstanding 500 500 Principal amount of 2025 Term Notes outstanding 500 500 Principal amount of 2023 Term Notes outstanding — 500 Unamortized discounts and debt issuance costs (11) (13) Net carrying amount of term notes 1,489 1,987 Less: current portion — (500) Term notes, non-current $ 1,489 $ 1,487 Fair value of term notes outstanding (Level 2) $ 1,375 $ 1,913 Interest expense recognized on our term notes, which included amortization of debt discounts and issuance costs, was $18 million and $55 million in Q3 2023 and YTD 2023, respectively, and $4 million and $13 million in Q3 2022 and YTD 2022, respectively. 0.550% Term Notes due 2023 (2023 Term Notes) and 2.550% Term Notes due 2031 (2031 Term Notes) In March 2021, we issued $500 million aggregate principal amount of 2023 Term Notes and $500 million aggregate principal amount of 2031 Term Notes. The 2023 Term Notes matured and were repaid in cash on March 23, 2023. The 2031 Term Notes, which mature on March 23, 2031, accrue interest at a rate of 2.550% per annum, payable semi-annually on March 23 and September 23 of each year. We may redeem for cash all or any portion of the 2031 Term Notes, at our option, at any time prior to maturity. Prior to December 23, 2030, the 2031 Term Notes are redeemable at make-whole premium redemption prices as defined in the applicable forms of note. After December 23, 2030, the notes are redeemable at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus any accrued and unpaid interest up to, but excluding, the redemption date. 5.800% Term Notes due 2025 (2025 Term Notes) and 5.750% Term Notes due 2027 (2027 Term Notes) In December 2022, we issued $500 million aggregate principal amount of 2025 Term Notes and $500 million aggregate principal amount of 2027 Term Notes. The 2025 Term Notes, which mature on December 12, 2025, and the 2027 Term Notes, which mature on December 13, 2027, accrue interest at a rate of 5.800% and 5.750% per annum, respectively, payable semi-annually. Interest for the 2025 Term Notes is payable on June 12 and December 12 of each year, beginning on June 12, 2023. Interest for the 2027 Term Notes is payable on June 13 and December 13 of each year, beginning on June 13, 2023. We may redeem for cash all or any portion of the 2025 or 2027 Term Notes, at our option, at any time prior to maturity. Prior to November 12, 2025 for the 2025 Term Notes and prior to November 13, 2027 for the 2027 Term Notes, the notes are redeemable at make-whole premium redemption prices as defined in the applicable forms of note. After November 12, 2025 for the 2025 Term Notes and after November 13, 2027 for the 2027 Term Notes, the notes are redeemable at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus any accrued and unpaid interest up to, but excluding, the redemption date. 0% Convertible Senior Notes due 2023 (2023 Convertible Notes) In August 2018, we issued $750 million aggregate principal amount of 2023 Convertible Notes. The notes were convertible into cash, shares of common stock, or a combination of cash and shares of common stock, at our election, based on conversion rates as defined in the indenture. The 2023 Convertible Notes matured on August 15, 2023, at which time the principal was repaid in cash. We did not issue any shares of common stock in connection with the 2023 Convertible Notes. Credit Agreement On January 4, 2023, we entered into a new credit agreement (the Credit Agreement), which provides us with a $750 million senior unsecured five The Credit Facility matures, and all amounts outstanding thereunder become due and payable in full, on January 4, 2028, subject to two one Any loans under the Credit Facility will have a variable interest rate based on either the term secured overnight financing rate or the alternate base rate, plus an applicable rate that varies with the Company’s debt rating and, in the case of loans bearing interest based on the term secured overnight financing rate, a credit spread adjustment equal to 0.10% per annum. The Credit Agreement includes an option for us to elect to increase the commitments under the Credit Facility or to enter into one or more tranches of term loans in the aggregate principal amount of up to $250 million, subject to the consent of the lenders providing the additional commitments or term loans, as applicable, and certain other conditions. The Credit Agreement contains financial and operating covenants. Pursuant to the Credit Agreement, we are required to maintain a ratio of total debt to annual earnings before interest, taxes, depreciation and amortization (EBITDA), calculated based on the four consecutive fiscal quarters ending with the most recent fiscal quarter, of not greater than 3.50 to 1.00 as of the end of each fiscal quarter. Upon the consummation of any Qualified Acquisition (as defined in the Credit Agreement) and us providing notice to the Administrative Agent, the ratio increases to 4.00 to 1.00 for the fiscal quarter in which the acquisition is consummated and the three consecutive fiscal quarters thereafter. The operating covenants include, among other things, limitations on (i) the incurrence of indebtedness by our subsidiaries, (ii) liens on our and our subsidiaries assets, and (iii) certain fundamental changes and the disposition of assets by us and our subsidiaries. The Credit Agreement contains other customary covenants, representations and warranties, and events of default.

Stockholders_ Equity

Stockholders’ Equity	9 Months Ended
Stockholders’ Equity	Oct. 01, 2023
Equity [Abstract]
Stockholders’ Equity	5. STOCKHOLDERS’ EQUITY In Q2 2023, the Company’s stockholders approved an amended and restated version of the Company’s 2015 Stock Incentive Plan (2015 Stock Plan) and increased the maximum number of shares authorized for issuance by 8.0 million shares. As of October 1, 2023, approximately 8.2 million shares remained available for future grants under the 2015 Stock Plan. Restricted Stock Restricted stock activity was as follows: Restricted Performance Stock Units (PSU) (1) Weighted-Average Grant Date Fair Value per Share Units in thousands RSU PSU Outstanding at January 1, 2023 1,611 74 $ 311.23 $ 446.74 Awarded 2,000 62 $ 197.09 $ 245.08 Vested (118) — $ 296.25 $ — Cancelled (411) (96) $ 255.53 $ 300.09 Outstanding at October 1, 2023 3,082 40 $ 245.37 $ 198.25 _____________ (1) The number of units reflect the estimated number of shares to be issued at the end of the performance period. For market-based PSU, the number of units reflect the estimated number of shares to be issued based on performance as of the current reporting period. Awarded units are presented net of performance adjustments. Liability-Classified RSU In Q1 2023, we granted RSU that were to be settled in cash if stockholder approval to increase our share reserve under the amended and restated 2015 Stock Plan was not obtained. In Q2 2023, the Company’s stockholders approved an amended and restated version of the 2015 Stock Plan and increased the maximum number of shares authorized for issuance. Upon such approval, all RSU previously accounted for as liability-classified awards, approximately 557,000 RSU, were reclassified to stockholders’ equity and accounted for prospectively as equity awards. There were no RSU liability-classified awards outstanding as of October 1, 2023. Market-Based PSU During YTD 2023, we granted PSU with a market condition that vest based on the Company’s relative total shareholder return (rTSR) as compared to a peer group of companies measured over a three-fiscal year awards is recognized over the requisite service period regardless of whether the market conditions are achieved. As of October 1, 2023, there were approximately 119,000 PSU with a rTSR market condition granted. Stock Options Stock option activity was as follows: Units in thousands Options Weighted-Average Performance Options (1) Weighted-Average Outstanding at January 1, 2023 187 $ 319.72 17 $ 85.54 Exercised (8) $ 71.09 (1) $ 16.69 Cancelled (135) $ 330.25 — $ — Outstanding at October 1, 2023 44 $ 330.25 16 $ 87.74 Exercisable at October 1, 2023 18 $ 330.25 — $ — _____________ (1) The number of units reflect awards that have been granted and for which it is assumed to be probable that the underlying performance goals will be achieved. Other Liability-Classified Awards We grant cash-based equity incentive awards to GRAIL employees. For purposes of valuation and performance measurement of the awards, GRAIL’s stand-alone valuation, as determined by GRAIL using a reasonable calculation and based on advice from independent valuation experts and analyses, is used. The awards generally have terms of four years with equal vesting annually, subject to continued employment through the vesting period. Cash-based equity incentive award activity was as follows: In millions Outstanding at January 1, 2023 $ 293 Granted 116 Vested and paid in cash (65) Cancelled (28) Change in fair value (8) Outstanding at October 1, 2023 $ 308 Estimated liability as of October 1, 2023 (included in accrued liabilities) $ 42 We recognized share-based compensation expense of $26 million and $72 million in Q3 2023 and YTD 2023, respectively, and $17 million and $46 million in Q3 2022 and YTD 2022, respectively. As of October 1, 2023, approximately $266 million of total unrecognized compensation cost related to awards issued to date was expected to be recognized over a weighted-average period of approximately 2.8 years. In connection with the acquisition of GRAIL, we assumed a performance-based award for which vesting is based on GRAIL’s future revenues. The award has an aggregate potential value of up to $78 million and expires, to the extent unvested, in August 2030. As of October 1, 2023, it was not probable that the performance conditions associated with the award will be achieved and, therefore, no share-based compensation expense, or corresponding liability, has been recognized in the condensed consolidated financial statements to-date. Employee Stock Purchase Plan The price at which common stock is purchased under the Employee Stock Purchase Plan (ESPP) is equal to 85% of the fair market value of the common stock on the first day of the offering period or purchase date, whichever is lower. During YTD 2023, approximately 0.4 million shares were issued under the ESPP. As of October 1, 2023, there were approximately 12.4 million shares available for issuance under the ESPP. The assumptions used and the resulting estimate of weighted-average fair value per share for stock purchased under the ESPP during YTD 2023 were as follows: Risk-free interest rate 0.78% - 5.54% Expected volatility 41% - 51% Expected term 0.5 - 1.1 year Expected dividends 0 % Weighted-average grant-date fair value per share $ 49.87 Share Repurchases We did not repurchase any shares during YTD 2023. As of October 1, 2023, authorizations to repurchase approximately $15 million of our common stock remained available under the $750 million share repurchase program authorized by our Board of Directors on February 5, 2020. The repurchases may be completed under a 10b5-1 plan or at management’s discretion. Share-Based Compensation Share-based compensation expense, which includes expense for both equity and liability-classified awards, reported in our condensed consolidated statements of operations was as follows: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Cost of product revenue $ 7 $ 7 $ 22 $ 20 Cost of service and other revenue 2 2 5 4 Research and development 36 37 117 112 Selling, general and administrative 41 37 142 130 Share-based compensation expense, before taxes 86 83 286 266 Related income tax benefits (19) (18) (65) (60) Share-based compensation expense, net of taxes $ 67 $ 65 $ 221 $ 206 As of October 1, 2023, approximately $582 million of total unrecognized compensation cost related to restricted stock, including RSU and PSU, stock options, including performance stock options, and ESPP shares issued to date was expected to be recognized over a weighted-average period of approximately 2.4 years.

Supplemental Balance Sheet Deta

Supplemental Balance Sheet Details	9 Months Ended
Supplemental Balance Sheet Details	Oct. 01, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Balance Sheet Details	6. SUPPLEMENTAL BALANCE SHEET DETAILS Accounts Receivable In millions October 1, January 1, Trade accounts receivable, gross $ 696 $ 675 Allowance for credit losses (6) (4) Total accounts receivable, net $ 690 $ 671 Inventory In millions October 1, January 1, Raw materials $ 278 $ 247 Work in process 423 386 Finished goods 35 28 Inventory, gross 736 661 Inventory reserve (121) (93) Total inventory, net $ 615 $ 568 Accrued Liabilities In millions October 1, January 1, Legal contingencies (1) $ 458 $ 473 Contract liabilities, current portion 242 245 Accrued compensation expenses 195 188 Accrued taxes payable 65 97 Operating lease liabilities, current portion 85 76 Liability-classified equity incentive awards 42 36 Other, including warranties (2) 155 117 Total accrued liabilities $ 1,242 $ 1,232 _____________ (1) See note “ 7. Legal Proceedings ” for additional details. (2) See table below for changes in the reserve for product warranties. Changes in the reserve for product warranties were as follows: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Balance at beginning of period $ 20 $ 21 $ 18 $ 22 Additions charged to cost of product revenue 10 5 30 17 Repairs and replacements (11) (7) (29) (20) Balance at end of period $ 19 $ 19 $ 19 $ 19 We generally provide a one-year warranty on instruments. Additionally, we provide a warranty on consumables through the expiration date, which generally ranges from six Restructuring In Q2 2023, we implemented a cost reduction initiative that included workforce reductions, the consolidation of certain facilities and other actions to reduce expenses, all as part of a plan to realign operating expenses while maintaining focus on our innovation roadmap and sustainable long-term growth. In Q3 2023 and YTD 2023, we recorded restructuring charges primarily consisting of asset impairment charges and employee separation costs. A summary of the pre-tax restructuring charges are as follows: In millions Q3 2023 YTD 2023 Employee separation costs $ 7 $ 33 Asset impairment charges (1) 49 56 Other costs 2 2 Total restructuring charges (2) $ 58 $ 91 _____________ (1) Primarily related to impairment of right-of-use assets and leasehold improvements for our i3 campus in San Diego, California. (2) For Q3 2023, $55 million was recorded in SG&A expense, $2 million in R&D expense, with the remainder recorded in cost of revenue. For YTD 2023 $74 million was recorded in SG&A expense, $13 million in R&D expense, with the remainder recorded in cost of revenue. We fully exited our i3 campus in San Diego, California in Q3 2023, which resulted in a right-of-use asset impairment of $33 million in Q3 2023 and $38 million in YTD 2023, recognized in selling, general and administrative expense. The impairment was determined by comparing the fair value of the impacted right-of-use asset to the carrying value of the asset as of the impairment measurement date. The fair value of the right-of-use asset was estimated using the discounted future cash flows method, which includes estimates and assumptions for future sublease rental rates that reflect current sublease market conditions, as well as a discount rate. The estimates and assumptions used in our assessment represent a Level 3 measurement because they are supported by little or no market activity and reflect our own assumptions in measuring fair value. We also recorded $14 million in Q3 2023 and $16 million in YTD 2023 of leasehold improvement impairment, recognized in selling, general and administrative expense, related to the exit of our i3 campus. We continue to evaluate our options with respect to our campus in Foster City, California. As of October 1, 2023, we had assets, consisting primarily of right-of-use assets and leasehold improvements, related to our Foster City campus of approximately $182 million. A summary of the restructuring liability is as follows: In millions Employee Separation Costs (1) Other Costs Total Expense recorded in YTD 2023 $ 33 $ 2 $ 35 Cash paid during YTD 2023 (30) (1) (31) Amount recorded in accrued liabilities as of October 1, 2023 $ 3 $ 1 $ 4 Estimated total restructuring costs to still be incurred $ 2 $ — $ 2 _____________ (1) It is expected that substantially all of the employee separation related restructuring charges will be incurred and paid by the end of 2023. Goodwill and Intangible Assets We test goodwill for impairment annually, as of May, or more frequently if events or circumstances indicate it is more likely than not that the fair value of a reporting unit is less than its carrying amount. We performed our annual impairment test in Q2 2023, as of May 2023. We performed a quantitative assessment for our two reporting units: Core Illumina and GRAIL. No impairment was recorded for either Core Illumina or GRAIL in Q2 2023. In Q3 2023, we concluded the sustained decrease in the Company’s stock price and overall market capitalization during the quarter was a circumstance indicating the fair value of a reporting unit might be less than its carrying amount that required an interim goodwill and intangible impairment test be performed. Based on our interim assessment, we concluded that our GRAIL reporting unit’s carrying value exceeded its estimated fair value. As a result, we recorded $712 million of goodwill impairment related to our GRAIL reporting unit in Q3 2023, primarily due to a decrease in the company’s consolidated market capitalization and a higher discount rate selected for the fair value calculation of the GRAIL reporting unit. No impairment was recorded for our Core Illumina reporting unit, noting its fair value exceeded its carrying value by more than $20 billion. We performed our impairment test using a combination of an income and a market approach to determine the fair value of each reporting unit. The income approach utilized the estimated discounted cash flows for each reporting unit, while the market approach utilized comparable company information. Estimates and assumptions used in the income approach included projected cash flows and a discount rate for each reporting unit. Discount rates were determined using a weighted average cost of capital for risk factors specific to each reporting unit and other market and industry data. For GRAIL, the selected discount rate was 24.0%. The estimates and assumptions used in our assessment represent a Level 3 measurement because they are supported by little or no market activity and reflect our own assumptions in measuring fair value. The assumptions used are inherently subject to uncertainty and we note that small changes in these assumptions could have a significant impact on the concluded value. An increase of 50 to 100 basis points to the discount rate used in our assessment for GRAIL would have resulted in additional goodwill impairment of approximately $200 million to $350 million for GRAIL. In order to further validate the reasonableness of the fair values concluded for our reporting units, a reconciliation to market capitalization was performed by estimating a reasonable implied control premium and other market factors. As a result of the impairment taken in Q3 2023, the carrying value of our GRAIL reporting unit now approximates its fair value. As such, changes in our future operating results, cash flows, share price (our share price has declined approximately 18% during the period October 1, 2023 to November 6, 2023), market capitalization or discount rates, as well as future regulatory decisions related to our acquisition of GRAIL, including the decision adopted by the European Commission on October 12, 2023 requiring us to divest GRAIL (refer to note “ 7. Legal Proceedings ”), used when conducting future goodwill impairment tests could affect the estimated fair values of our reporting units and may result in additional impairment charges in the future. We will continue to monitor events and circumstances which may suggest that interim impairment indicators are present prior to the annual impairment test. As of October 1, 2023, remaining goodwill allocated to GRAIL was $1,466 million. In conjunction with the interim goodwill impairment test, we also evaluated the in-process research and development (IPR&D) asset assigned to the GRAIL reporting unit for potential impairment. We performed our impairment test by comparing the carrying value of the IPR&D asset to its estimated fair value, which was determined by the income approach, using a discounted cash flow model. Estimates and assumptions used in the income approach, which represent a Level 3 measurement, included projected cash flows and a selected discount rate of 19.0%. Based on our impairment test, the carrying value of the GRAIL IPR&D asset exceeded its estimated fair value and we recorded an impairment of $109 million in Q3 2023, primarily due to a decrease in projected cash flows and a higher discount rate selected for the fair value calculation of the GRAIL IPR&D asset. As of October 1, 2023, the carrying value of the GRAIL IPR&D asset was $561 million. We also performed a recoverability test for the definite-lived intangible assets assigned to the GRAIL reporting unit, which includes developed technology and trade name, noting no impairment. No impairment was noted for Core Illumina definite-lived intangible assets. Changes to goodwill during YTD 2023 were as follows: In millions Balance as of January 1, 2023 (1) $ 3,239 Impairment (712) Balance as of October 1, 2023 $ 2,527 _____________ (1) The balance as of January 1, 2023 is inclusive of a $3,914 million goodwill impairment related to our GRAIL reporting unit in Q3 2022. Derivative Financial Instruments We are exposed to foreign exchange rate risks in the normal course of business and use derivative financial instruments to partially offset this exposure. We do not use derivative financial instruments for speculative or trading purposes. Foreign exchange contracts are carried at fair value in other current assets, other assets, accrued liabilities, or other long-term liabilities, as appropriate, on the condensed consolidated balance sheets. We use foreign exchange forward contracts to manage foreign currency risks related to monetary assets and liabilities denominated in currencies other than the U.S. dollar. These derivative financial instruments have terms of one month or less and are not designated as hedging instruments. Changes in fair value of these derivatives are recognized in other expense, net, along with the re-measurement gain or loss on the foreign currency denominated assets or liabilities. As of October 1, 2023, we had foreign exchange forward contracts in place to hedge exposures in the euro, Japanese yen, Australian dollar, Canadian dollar, Singapore dollar, Chinese Yuan Renminbi, and British pound. As of October 1, 2023 and January 1, 2023, the total notional amounts of outstanding forward contracts in place for these foreign currency purchases were $912 million and $485 million, respectively. On July 25, 2023, we entered into forward contracts for a total notional amount of €432 million to hedge the foreign currency exposure for the fine imposed by the European Commission on July 12, 2023. We also use foreign currency forward contracts to hedge portions of our foreign currency exposure associated with forecasted revenue transactions. These derivative financial instruments have terms up to 24 months and are designated as cash flow hedges. Changes in fair value of our cash flow hedges are recorded as a component of accumulated other comprehensive income and are reclassified to revenue in the same period the underlying hedged transactions are recorded. We regularly review the effectiveness of our cash flow hedges and consider them to be ineffective if it becomes probable that the forecasted transactions will not occur in the identified period. Changes in fair value of the ineffective portions of our cash flow hedges, if any, are recognized in other expense, net. As of October 1, 2023, we had foreign currency forward contracts in place to hedge exposures associated with forecasted revenue transactions denominated in the euro, Japanese yen, Australian dollar, Canadian dollar, and Chinese Yuan Renminbi. As of October 1, 2023 and January 1, 2023, the total notional amounts of outstanding cash flow hedge contracts in place for these foreign currency purchases were $663 million and $425 million, respectively. We reclassified $5 million and $9 million to revenue in Q3 2023 and YTD 2023, respectively, and $16 million and $32 million in Q3 2022 and YTD 2022, respectively. As of October 1, 2023, the fair value of the foreign currency forward contracts recorded in total assets and total liabilities was $27 million and $1 million, respectively. As of January 1, 2023, the fair value of the foreign currency forward contracts recorded in total assets and total liabilities was $8 million and $6 million, respectively. The estimated net gains reported in accumulated other comprehensive income that are expected to be reclassified into earnings within the next 12 months are $22 million as of October 1, 2023.

Legal Proceedings

Legal Proceedings	9 Months Ended
Legal Proceedings	Oct. 01, 2023
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	7. LEGAL PROCEEDINGS We are involved in various lawsuits and claims arising in the ordinary course of business, including actions with respect to intellectual property, employment, and contractual matters. In connection with these matters, we assess, on a regular basis, the probability and range of possible loss based on the developments in these matters. A liability is recorded in the condensed consolidated financial statements if it is believed to be probable that a loss has been incurred and the amount of the loss can be reasonably estimated. Because litigation is inherently unpredictable and unfavorable resolutions could occur, assessing contingencies is highly subjective and requires judgments about future events. We regularly review outstanding legal matters to determine the adequacy of the liabilities accrued and related disclosures in consideration of many factors, which include, but are not limited to, past history, scientific and other evidence, and the specifics and status of each matter. We may change our estimates if our assessment of the various factors changes and the amount of ultimate loss may differ from our estimates, resulting in a material effect on our business, financial condition, results of operations, and/or cash flows. Acquisition of GRAIL Our acquisition of GRAIL remains subject to ongoing legal and regulatory proceedings in the United States and in the European Union. On March 30, 2021, the U.S. Federal Trade Commission (the FTC) filed an administrative complaint and a motion for a preliminary injunction in the United States District Court for the District of Columbia. In both actions, the FTC alleged that our acquisition of GRAIL would violate Section 7 of the Clayton Act, as amended, 15 U.S.C. § 18. We filed an answer to the FTC’s complaint in federal district court on April 6, 2021, and in the administrative court on April 13, 2021. On April 20, 2021, the United States District Court for the District of Columbia granted our motion to transfer venue to the United States District Court for the Southern District of California. On May 28, 2021, the district court granted the FTC’s motion to dismiss the complaint without prejudice. The administrative trial commenced on August 24, 2021. On September 1, 2022, the administrative law judge (the ALJ) ruled in favor of Illumina and found that the acquisition of GRAIL did not violate Section 7 of the Clayton Act. In the decision, the ALJ found that the FTC’s complaint counsel had failed to prove its prima facie case that Illumina’s acquisition of GRAIL would result in harm to competition in a putative market for multi-cancer early detection (MCED) tests. The FTC’s complaint counsel appealed the ALJ’s decision to the full FTC on September 2, 2022. The appeal was fully briefed as of November 10, 2022 and oral argument occurred on December 13, 2022. On March 31, 2023, the FTC issued an opinion and order (the FTC Order) requiring Illumina to divest GRAIL, reversing the ALJ’s ruling. On April 5, 2023, Illumina filed a petition for review of the FTC Order in the U.S. Court of Appeals for the Fifth Circuit. On April 24, 2023, the FTC granted a motion staying in its entirety the FTC Order pending resolution of Illumina’s Fifth Circuit appeal. The appeal was fully briefed as of August 16, 2023 and oral argument occurred on September 12, 2023. We intend to continue to vigorously defend against the FTC action. On April 19, 2021, the European Commission accepted a request for a referral of the GRAIL acquisition for European Union merger review, submitted by a Member State of the European Union (France), and joined by several other Member States (Belgium, Greece, Iceland, the Netherlands and Norway), under Article 22(1) of Council Regulation (EC) No 139/2004 (the EU Merger Regulation). The European Commission had never solicited referrals to take jurisdiction over an acquisition of a U.S. company that had no revenue in Europe. On April 29, 2021, we filed an action in the General Court of the European Union (the EU General Court) asking for annulment of the European Commission’s assertion of jurisdiction to review the acquisition under Article 22 of the EU Merger Regulation, as the acquisition does not meet the jurisdictional criteria under the EU Merger Regulation or under the national merger control laws of any Member State of the European Union. On December 16, 2021, the EU General Court held a hearing regarding the European Commission’s assertion of jurisdiction. On July 13, 2022, the EU General Court reached a decision in favor of the European Commission, holding that the European Commission has jurisdiction under the EU Merger Regulation to review the acquisition. On September 22, 2022, we filed an appeal in the Court of Justice of the European Union asking for annulment of the EU General Court’s decision. On October 29, 2021, the European Commission adopted an order imposing interim measures (the Initial Interim Measures Order). As the Initial Interim Measures Order was set to expire on November 3, 2022, the European Commission adopted a new order imposing interim measures (the New Interim Measures Order) on October 28, 2022. On December 1, 2021, we filed an action with the EU General Court asking for annulment of the Initial Interim Measures Order. The hearing of that application has been stayed pending our appeal of the judgment of the EU General Court regarding the European Commission’s assertion of jurisdiction. On January 10, 2023, we filed an action with the EU General Court asking for annulment of the New Interim Measures Order. On January 20, 2023, the European Commission requested that these proceedings be stayed pending our appeal on jurisdiction. We submitted a filing indicating that we had no objections to the European Commission’s request, and the EU General Court stayed the proceedings on February 21, 2023. On September 6, 2022, the European Commission announced that it had completed its Phase II review of the acquisition of GRAIL and adopted a final decision (the Prohibition Decision), which found that, in its view, our acquisition of GRAIL was incompatible with the internal market in Europe because it results in a significant impediment to effective competition. On November 17, 2022, we filed an action with the EU General Court asking for annulment of the Prohibition Decision. On October 12, 2023, the European Commission adopted a decision requiring us to (among other things) divest GRAIL, and replacing the interim measures set forth in the New Interim Measures Order with substantially equivalent transitional measures (the EC Divestment Decision). We intend to appeal the EC Divestment Decision. On July 12, 2023, the European Commission adopted a final decision finding that we breached the EU Merger Regulation by, in its view, acquiring the possibility to exert decisive influence over GRAIL and exerting such influence during the pendency of the European Commission’s review (the Article 14(2)(b) Decision). The European Commission therefore imposed a fine pursuant to Article 14(2)(b) of the EU Merger Regulation of approximately €432 million, representing the maximum fine of 10% of our consolidated annual revenues for fiscal year 2022. We provided guarantees in October 2023 to satisfy the obligation in lieu of cash payment while we appeal the European Commission’s jurisdictional decision and fine decision. The fine is accruing interest at a rate of 5.5% per annum, beginning in October 2023, while it is outstanding. As of October 1, 2023, we accrued $458 million, including related foreign currency gains (which were recorded in other expense, net), included in accrued liabilities. We appealed the Article 14(2)(b) Decision on September 26, 2023. SEC Inquiry Letter In July 2023, we were informed that the staff of the SEC was conducting an investigation relating to Illumina and was requesting documents and communications primarily related to Illumina’s acquisition of GRAIL and certain statements and disclosures concerning GRAIL, its products and its acquisition, and related to the conduct and compensation of certain members of Illumina and GRAIL management, among other things. Illumina is cooperating with the SEC in this investigation. Derivative and Class Action Complaint On October 17, 2023, a stockholder derivative and class action complaint captioned Icahn Partners LP, et al. v. deSouza, et al., purportedly brought on behalf of Illumina and public holders of Illumina’s common stock, was filed in the Delaware Court of Chancery against certain current and former directors (including our former Chief Executive Officer). We are named as a nominal defendant in the complaint. The lawsuit alleges the named directors breached their fiduciary duties by knowingly causing Illumina to unlawfully close the GRAIL acquisition, concealing material facts related to the GRAIL acquisition and making inadequate disclosures. Prior to the filing of the complaint, the purported stockholders did not make a demand that our Board of Directors pursue the claims asserted therein. The complaint seeks damages, costs and expenses, including attorney fees, the certification and consolidation of a putative class, the issuance of amended disclosures, the removal of conflicted directors and declaratory and other equitable relief. Since the lawsuit is brought in part on behalf of Illumina as a nominal defendant, the alleged damages were allegedly suffered by us. We deny the allegations in the complaint and intend to vigorously defend the litigation. In light of the fact that the lawsuit is in an early stage, we cannot predict the ultimate outcome of the suit.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Oct. 01, 2023
Income Tax Disclosure [Abstract]
Income Taxes	8. INCOME TAXES Our effective tax rate may vary from the U.S. federal statutory tax rate due to the change in the mix of earnings in tax jurisdictions with different statutory rates, benefits related to tax credits, and the tax impact of non-deductible expenses and other permanent differences between income before income taxes and taxable income. Our effective tax rates for Q3 2023 and YTD 2023 were 3.6% and (3.8)%, respectively, compared to (4.0)% and (2.3)% in Q3 2022 and YTD 2022, respectively. The variance from the U.S. federal statutory tax rate of 21% in Q3 2023 and YTD 2023 was primarily attributable to the $149 million income tax expense impact from the impairment of goodwill, which is nondeductible for tax purposes, the $20 million and $84 million income tax expense impact of research and development expense capitalization for tax purposes, respectively, and the $38 million and $63 million income tax expense impact of GRAIL pre-acquisition net operating losses on global intangible low-taxed income (GILTI) and the utilization of U.S. foreign tax credits, respectively. This was partially offset by the mix of earnings in jurisdictions with lower statutory tax rates than the U.S. federal statutory tax rate, such as in Singapore. Historically, we calculated the provision/(benefit) for income taxes for interim periods utilizing an estimated annual effective tax rate applied to the income/(loss) for the reporting period, except in Q2 2023 when a year-to-date effective tax rate method was utilized . We determined the estimated annual effective tax rate method would provide a more reliable estimate of the provision for income taxes for Q3 2023 and YTD 2023, since minor changes in the estimated income/(loss) before income taxes would not result in significant changes in the estimated annual effective tax rate. As of October 1, 2023 and January 1, 2023, prepaid income taxes, included within prepaid expenses and other current assets on the condensed consolidated balance sheets, were $78 million and $116 million, respectively.

Segment Information

Segment Information	9 Months Ended
Segment Information	Oct. 01, 2023
Segment Reporting [Abstract]
Segment Information	9. SEGMENT INFORMATION We have two reportable segments, Core Illumina and GRAIL. We report segment information based on the management approach, which designates the internal reporting used by the Chief Operating Decision Maker (CODM) for making decisions and assessing performance as the source of our reportable segments. The CODM allocates resources and assesses the performance of each operating segment using information about its revenue and income (loss) from operations. Our CODM does not evaluate our operating segments using discrete asset information. We do not allocate expenses between segments. Core Illumina sells products and provides services to GRAIL, and vice versa, in accordance with contractual agreements between the entities. Core Illumina: Core Illumina’s products and services serve customers in the research, clinical and applied markets, and enable the adoption of a variety of genomic solutions. Core Illumina includes all of our operations, excluding the results of GRAIL. GRAIL: GRAIL is a healthcare company focused on early detection of multiple cancers. In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Revenue: Core Illumina $ 1,106 $ 1,110 $ 3,341 $ 3,487 GRAIL 21 10 62 32 Eliminations (8) (5) (21) (18) Consolidated revenue $ 1,119 $ 1,115 $ 3,382 $ 3,501 Income (loss) from operations: Core Illumina $ 262 $ 445 $ 519 $ 411 GRAIL (1,015) (4,101) (1,424) (4,460) Eliminations (1) (1) — (3) Consolidated loss from operations $ (754) $ (3,657) $ (905) $ (4,052) Total other expense, net primarily relates to Core Illumina and we do not allocate income taxes to our segments.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended							9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Oct. 01, 2023	Jul. 02, 2023	Apr. 02, 2023	Jan. 01, 2023	Oct. 02, 2022	Jul. 03, 2022	Apr. 03, 2022	Oct. 01, 2023	Oct. 02, 2022
Pay vs Performance Disclosure
Net loss	$ (754)	$ (234)	$ 3	$ (139)	$ (3,816)	$ (535)	$ 86	$ (986)	$ (4,265)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
Insider Trading Arrangements	Oct. 01, 2023 shares	Oct. 01, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		ADOPTIONS, MODIFICATIONS OR TERMINATIONS OF TRADING PLANS During the quarterly period ended October 1, 2023, the following directors and officers adopted, modified or terminated 10b5-1 plans: • On September 26, 2023, Phil Febbo, our former Chief Medical Officer, terminated a trading arrangement he had previously adopted with respect to the sale of securities of the Company’s common stock (a “Rule 10b5-1 Trading Arrangement”) in connection with his departure from the Company. Mr. Febbo’s Rule 10b5-1 Trading Arrangement was adopted on May 30, 2023, had a termination date of December 31, 2024, and provided for the sale of up to 9,294 shares of common stock pursuant to the terms of the plan.
Rule 10b5-1 Arrangement Adopted	true
Non-Rule 10b5-1 Arrangement Adopted	false
Adoption Date	May 30, 2023
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Phil Febbo [Member]
Trading Arrangements, by Individual
Name	Phil Febbo
Title	Chief Medical Officer
Arrangement Duration	581 days
Aggregate Available	9,294	9,294

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	9 Months Ended
Organization and Significant Accounting Policies (Policies)	Oct. 01, 2023
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements.
Consolidation	The unaudited condensed consolidated financial statements include our accounts, our wholly-owned subsidiaries, and majority-owned or controlled companies. All intercompany transactions and balances have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. In management’s opinion, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, considered necessary for a fair presentation of the results for the interim periods presented.
Fiscal Year	Our fiscal year is the 52 or 53 weeks ending the Sunday closest to December 31, with quarters of 13 or 14 weeks ending the Sunday closest to March 31, June 30, September 30, and December 31. References to Q3 2023 and Q3 2022 refer to the three months ended October 1, 2023 and October 2, 2022, respectively, which were both 13 weeks, and references to year-to-date (YTD) 2023 and 2022 refer to the nine months ended October 1, 2023 and October 2, 2022, respectively, which were both 39 weeks.
Loss per Share	Basic loss per share is computed based on the weighted average number of common shares outstanding during the period. Diluted loss per share is computed based on the sum of the weighted average number of common shares and potentially dilutive common shares outstanding during the period. In loss periods, basic and diluted loss per share are identical since the effect of potentially dilutive common shares is antidilutive and therefore excluded.Potentially dilutive common shares consist of shares issuable under convertible senior notes and equity awards. We utilize the if-converted method to calculate the impact of convertible senior notes on diluted loss per share. Potentially dilutive common shares from equity awards are determined using the average share price for each period under the treasury stock method. In addition, proceeds from exercise of equity awards and the average amount of unrecognized compensation expense for equity awards are assumed to be used to repurchase shares.
Warranties	We generally provide a one-year warranty on instruments. Additionally, we provide a warranty on consumables through the expiration date, which generally ranges from six
Derivatives	We are exposed to foreign exchange rate risks in the normal course of business and use derivative financial instruments to partially offset this exposure. We do not use derivative financial instruments for speculative or trading purposes. Foreign exchange contracts are carried at fair value in other current assets, other assets, accrued liabilities, or other long-term liabilities, as appropriate, on the condensed consolidated balance sheets.

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	9 Months Ended
Organization and Significant Accounting Policies (Tables)	Oct. 01, 2023
Accounting Policies [Abstract]
Schedule of Calculation of Weighted Average Shares Used to Calculate Basic and Diluted Net (Loss) Income Per Share	The following table presents the weighted average shares used to calculate basic and diluted loss per share: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Weighted average shares used in calculating basic loss per share 158 157 158 157 Weighted average shares used in calculating diluted loss per share 158 157 158 157 Antidilutive shares: Convertible senior notes 1 2 1 2 Equity awards 3 2 3 2 Potentially dilutive shares excluded from calculation due to antidilutive effect 4 4 4 4

Revenue (Tables)

Revenue (Tables)	9 Months Ended
Revenue (Tables)	Oct. 01, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Revenue by Source Q3 2023 Q3 2022 In millions Sequencing Microarray Total Sequencing Microarray Total Consumables $ 689 $ 71 $ 760 $ 720 $ 76 $ 796 Instruments 178 3 181 162 5 167 Total product revenue 867 74 941 882 81 963 Service and other revenue 162 16 178 133 19 152 Total revenue $ 1,029 $ 90 $ 1,119 $ 1,015 $ 100 $ 1,115 YTD 2023 YTD 2022 In millions Sequencing Microarray Total Sequencing Microarray Total Consumables $ 2,108 $ 219 $ 2,327 $ 2,237 $ 225 $ 2,462 Instruments 524 13 537 563 14 577 Total product revenue 2,632 232 2,864 2,800 239 3,039 Service and other revenue 456 62 518 390 72 462 Total revenue $ 3,088 $ 294 $ 3,382 $ 3,190 $ 311 $ 3,501 Revenue by Geographic Area Based on region of destination (in millions) Q3 2023 Q3 2022 (1) YTD 2023 YTD 2022 (1) Americas $ 663 $ 597 $ 1,920 $ 1,885 Europe 260 259 825 819 Greater China (2) 98 133 302 378 Asia-Pacific, Middle East, and Africa (3) 98 126 335 419 Total revenue $ 1,119 $ 1,115 $ 3,382 $ 3,501 _____________ (1) We implemented a new global commercial structure in Q1 2023 to improve operating efficiencies and better align with local markets. We integrated Asia-Pacific and Japan with emerging markets across the Middle East, Africa, Turkey, and Commonwealth of Independent States (CIS). Beginning in Q1 2023, and going forward, we will report regional results for the following regions: Americas, Europe, Greater China, and Asia-Pacific, Middle East and Africa (AMEA). Prior period amounts have been reclassified to conform to this new presentation. (2) Region includes revenue from China, Taiwan, and Hong Kong. (3) Region includes revenue from Russia and Turkey.

Investments and Fair Value Me_2

Investments and Fair Value Measurements (Tables)	9 Months Ended
Investments and Fair Value Measurements (Tables)	Oct. 01, 2023
Fair Value Disclosures [Abstract]
Schedule of Marketable Securities	Gains and losses recognized in other expense, net on our marketable equity securities were as follows: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Net gains (losses) recognized during the period on marketable equity securities $ — $ 3 $ (2) $ (66) Less: Net losses recognized during the period on marketable equity securities sold during the period — — (2) — Net unrealized gains (losses) recognized during the period on marketable equity securities still held at the reporting date $ — $ 3 $ — $ (66)
Schedule of Hierarchy for Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents the hierarchy for assets and liabilities measured at fair value on a recurring basis: October 1, 2023 January 1, 2023 In millions Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Money market funds (cash equivalents) $ 646 $ — $ — $ 646 $ 1,642 $ — $ — $ 1,642 Marketable equity securities 6 — — 6 26 — — 26 Helix contingent value right — — 66 66 — — 58 58 Deferred compensation plan assets — 57 — 57 — 52 — 52 Total assets measured at fair value $ 652 $ 57 $ 66 $ 775 $ 1,668 $ 52 $ 58 $ 1,778 Liabilities: Contingent consideration liabilities $ — $ — $ 330 $ 330 $ — $ — $ 412 $ 412 Deferred compensation plan liability — 54 — 54 — 51 — 51 Total liabilities measured at fair value $ — $ 54 $ 330 $ 384 $ — $ 51 $ 412 $ 463
Schedule of Changes in Estimated Fair Value of Acquisition Related Contingent Consideration Liabilities	Changes in the estimated fair value of our contingent consideration liabilities during YTD 2023 were as follows: In millions Balance as of January 1, 2023 $ 412 Change in estimated fair value (82) Balance as of October 1, 2023 $ 330

Debt (Tables)

Debt (Tables)	9 Months Ended
Debt (Tables)	Oct. 01, 2023
Debt Disclosure [Abstract]
Schedule of Debt Obligations	Summary of Term Debt Obligations In millions October 1, January 1, Principal amount of 2031 Term Notes outstanding $ 500 $ 500 Principal amount of 2027 Term Notes outstanding 500 500 Principal amount of 2025 Term Notes outstanding 500 500 Principal amount of 2023 Term Notes outstanding — 500 Unamortized discounts and debt issuance costs (11) (13) Net carrying amount of term notes 1,489 1,987 Less: current portion — (500) Term notes, non-current $ 1,489 $ 1,487 Fair value of term notes outstanding (Level 2) $ 1,375 $ 1,913

Stockholders_ Equity (Tables)

Stockholders’ Equity (Tables)	9 Months Ended
Stockholders’ Equity (Tables)	Oct. 01, 2023
Equity [Abstract]
Schedule of Restricted Stock Activity and Related Information, Restricted Stock	Restricted stock activity was as follows: Restricted Performance Stock Units (PSU) (1) Weighted-Average Grant Date Fair Value per Share Units in thousands RSU PSU Outstanding at January 1, 2023 1,611 74 $ 311.23 $ 446.74 Awarded 2,000 62 $ 197.09 $ 245.08 Vested (118) — $ 296.25 $ — Cancelled (411) (96) $ 255.53 $ 300.09 Outstanding at October 1, 2023 3,082 40 $ 245.37 $ 198.25 _____________ (1) The number of units reflect the estimated number of shares to be issued at the end of the performance period. For market-based PSU, the number of units reflect the estimated number of shares to be issued based on performance as of the current reporting period. Awarded units are presented net of performance adjustments.
Schedule of Restricted Stock Activity and Related Information, Performance Units	Restricted stock activity was as follows: Restricted Performance Stock Units (PSU) (1) Weighted-Average Grant Date Fair Value per Share Units in thousands RSU PSU Outstanding at January 1, 2023 1,611 74 $ 311.23 $ 446.74 Awarded 2,000 62 $ 197.09 $ 245.08 Vested (118) — $ 296.25 $ — Cancelled (411) (96) $ 255.53 $ 300.09 Outstanding at October 1, 2023 3,082 40 $ 245.37 $ 198.25 _____________ (1) The number of units reflect the estimated number of shares to be issued at the end of the performance period. For market-based PSU, the number of units reflect the estimated number of shares to be issued based on performance as of the current reporting period. Awarded units are presented net of performance adjustments.
Schedule of Stock Option Activity Under all Stock Option Plans	Stock option activity was as follows: Units in thousands Options Weighted-Average Performance Options (1) Weighted-Average Outstanding at January 1, 2023 187 $ 319.72 17 $ 85.54 Exercised (8) $ 71.09 (1) $ 16.69 Cancelled (135) $ 330.25 — $ — Outstanding at October 1, 2023 44 $ 330.25 16 $ 87.74 Exercisable at October 1, 2023 18 $ 330.25 — $ — _____________ (1) The number of units reflect awards that have been granted and for which it is assumed to be probable that the underlying performance goals will be achieved.
Schedule of Share-based Payment Arrangement, Liability - Classified Awards, Activity	Cash-based equity incentive award activity was as follows: In millions Outstanding at January 1, 2023 $ 293 Granted 116 Vested and paid in cash (65) Cancelled (28) Change in fair value (8) Outstanding at October 1, 2023 $ 308 Estimated liability as of October 1, 2023 (included in accrued liabilities) $ 42
Schedule of Assumptions used to Estimate the Weighted-Average Fair Value Per Share for Stock Purchase under the Employee Stock Purchase Plan	The assumptions used and the resulting estimate of weighted-average fair value per share for stock purchased under the ESPP during YTD 2023 were as follows: Risk-free interest rate 0.78% - 5.54% Expected volatility 41% - 51% Expected term 0.5 - 1.1 year Expected dividends 0 % Weighted-average grant-date fair value per share $ 49.87
Schedule of Share-based Compensation Expense for all Stock Awards	Share-based compensation expense, which includes expense for both equity and liability-classified awards, reported in our condensed consolidated statements of operations was as follows: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Cost of product revenue $ 7 $ 7 $ 22 $ 20 Cost of service and other revenue 2 2 5 4 Research and development 36 37 117 112 Selling, general and administrative 41 37 142 130 Share-based compensation expense, before taxes 86 83 286 266 Related income tax benefits (19) (18) (65) (60) Share-based compensation expense, net of taxes $ 67 $ 65 $ 221 $ 206

Supplemental Balance Sheet De_2

Supplemental Balance Sheet Details (Tables)	9 Months Ended
Supplemental Balance Sheet Details (Tables)	Oct. 01, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Accounts Receivable	Accounts Receivable In millions October 1, January 1, Trade accounts receivable, gross $ 696 $ 675 Allowance for credit losses (6) (4) Total accounts receivable, net $ 690 $ 671
Schedule of Inventory	Inventory In millions October 1, January 1, Raw materials $ 278 $ 247 Work in process 423 386 Finished goods 35 28 Inventory, gross 736 661 Inventory reserve (121) (93) Total inventory, net $ 615 $ 568
Schedule of Accrued Liabilities	Accrued Liabilities In millions October 1, January 1, Legal contingencies (1) $ 458 $ 473 Contract liabilities, current portion 242 245 Accrued compensation expenses 195 188 Accrued taxes payable 65 97 Operating lease liabilities, current portion 85 76 Liability-classified equity incentive awards 42 36 Other, including warranties (2) 155 117 Total accrued liabilities $ 1,242 $ 1,232 _____________ (1) See note “ 7. Legal Proceedings ” for additional details. (2) See table below for changes in the reserve for product warranties.
Schedule of Changes in Reserve for Product Warranties	Changes in the reserve for product warranties were as follows: In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Balance at beginning of period $ 20 $ 21 $ 18 $ 22 Additions charged to cost of product revenue 10 5 30 17 Repairs and replacements (11) (7) (29) (20) Balance at end of period $ 19 $ 19 $ 19 $ 19
Schedule Of Restructuring and Related Costs	A summary of the pre-tax restructuring charges are as follows: In millions Q3 2023 YTD 2023 Employee separation costs $ 7 $ 33 Asset impairment charges (1) 49 56 Other costs 2 2 Total restructuring charges (2) $ 58 $ 91 _____________ (1) Primarily related to impairment of right-of-use assets and leasehold improvements for our i3 campus in San Diego, California. (2) For Q3 2023, $55 million was recorded in SG&A expense, $2 million in R&D expense, with the remainder recorded in cost of revenue. For YTD 2023 $74 million was recorded in SG&A expense, $13 million in R&D expense, with the remainder recorded in cost of revenue. A summary of the restructuring liability is as follows: In millions Employee Separation Costs (1) Other Costs Total Expense recorded in YTD 2023 $ 33 $ 2 $ 35 Cash paid during YTD 2023 (30) (1) (31) Amount recorded in accrued liabilities as of October 1, 2023 $ 3 $ 1 $ 4 Estimated total restructuring costs to still be incurred $ 2 $ — $ 2 _____________
Schedule of Goodwill and Intangible Assets	Changes to goodwill during YTD 2023 were as follows: In millions Balance as of January 1, 2023 (1) $ 3,239 Impairment (712) Balance as of October 1, 2023 $ 2,527 _____________ (1) The balance as of January 1, 2023 is inclusive of a $3,914 million goodwill impairment related to our GRAIL reporting unit in Q3 2022.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
Segment Information (Tables)	Oct. 01, 2023
Segment Reporting [Abstract]
Schedule of Operating Performance and Assets by Segment	In millions Q3 2023 Q3 2022 YTD 2023 YTD 2022 Revenue: Core Illumina $ 1,106 $ 1,110 $ 3,341 $ 3,487 GRAIL 21 10 62 32 Eliminations (8) (5) (21) (18) Consolidated revenue $ 1,119 $ 1,115 $ 3,382 $ 3,501 Income (loss) from operations: Core Illumina $ 262 $ 445 $ 519 $ 411 GRAIL (1,015) (4,101) (1,424) (4,460) Eliminations (1) (1) — (3) Consolidated loss from operations $ (754) $ (3,657) $ (905) $ (4,052) Total other expense, net primarily relates to Core Illumina and we do not allocate income taxes to our segments.

Organization and Significant _4

Organization and Significant Accounting Policies - Summary of Calculation of Weighted Average Shares used to Calculate Basic and Diluted Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Weighted average shares used to calculate basic and diluted earnings per share
Weighted average shares used in calculating basic loss per share (in shares)	158	157	158	157
Weighted average shares used in calculating diluted loss per share (in shares)	158	157	158	157
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares excluded from calculation due to antidilutive effect (in shares)	4	4	4	4
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares excluded from calculation due to antidilutive effect (in shares)	1	2	1	2
Equity awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares excluded from calculation due to antidilutive effect (in shares)	3	2	3	2

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Disaggregation of Revenue [Line Items]
Consolidated revenue	$ 1,119	$ 1,115	$ 3,382	$ 3,501
Americas
Disaggregation of Revenue [Line Items]
Consolidated revenue	663	597	1,920	1,885
Europe
Disaggregation of Revenue [Line Items]
Consolidated revenue	260	259	825	819
Greater China
Disaggregation of Revenue [Line Items]
Consolidated revenue	98	133	302	378
Asia-Pacific, Middle East, and Africa
Disaggregation of Revenue [Line Items]
Consolidated revenue	98	126	335	419
Total product revenue
Disaggregation of Revenue [Line Items]
Consolidated revenue	941	963	2,864	3,039
Consumables
Disaggregation of Revenue [Line Items]
Consolidated revenue	760	796	2,327	2,462
Instruments
Disaggregation of Revenue [Line Items]
Consolidated revenue	181	167	537	577
Service and other revenue
Disaggregation of Revenue [Line Items]
Consolidated revenue	178	152	518	462
Sequencing
Disaggregation of Revenue [Line Items]
Consolidated revenue	1,029	1,015	3,088	3,190
Sequencing \| Total product revenue
Disaggregation of Revenue [Line Items]
Consolidated revenue	867	882	2,632	2,800
Sequencing \| Consumables
Disaggregation of Revenue [Line Items]
Consolidated revenue	689	720	2,108	2,237
Sequencing \| Instruments
Disaggregation of Revenue [Line Items]
Consolidated revenue	178	162	524	563
Sequencing \| Service and other revenue
Disaggregation of Revenue [Line Items]
Consolidated revenue	162	133	456	390
Microarray
Disaggregation of Revenue [Line Items]
Consolidated revenue	90	100	294	311
Microarray \| Total product revenue
Disaggregation of Revenue [Line Items]
Consolidated revenue	74	81	232	239
Microarray \| Consumables
Disaggregation of Revenue [Line Items]
Consolidated revenue	71	76	219	225
Microarray \| Instruments
Disaggregation of Revenue [Line Items]
Consolidated revenue	3	5	13	14
Microarray \| Service and other revenue
Disaggregation of Revenue [Line Items]
Consolidated revenue	$ 16	$ 19	$ 62	$ 72

Revenue - Performance Obligatio

Revenue - Performance Obligation (Details) $ in Millions	9 Months Ended
Revenue - Performance Obligation (Details) $ in Millions	Oct. 01, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 743
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Product or service delivery period (in months)	3 months
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Product or service delivery period (in months)	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-02
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent of remaining performance obligation (as a percent)	83%
Expected timing of remaining performance obligation (in months)	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent of remaining performance obligation (as a percent)	10%
Expected timing of remaining performance obligation (in months)	12 months

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Revenue - Narrative (Details) - USD ($) $ in Millions	Oct. 01, 2023	Oct. 01, 2023	Jan. 01, 2023
Revenue from Contract with Customer [Abstract]
Contract asset	$ 19	$ 19	$ 17
Contract with customer, liability	315	315	308
Contract liabilities, current portion	242	242	$ 245
Revenue recognized	$ 43	$ 206

Investments and Fair Value Me_3

Investments and Fair Value Measurements - Narrative (Details) $ in Thousands		1 Months Ended	3 Months Ended								9 Months Ended
	Aug. 18, 2021 USD ($)	Apr. 30, 2019	Oct. 01, 2023 USD ($)	Jul. 02, 2023 USD ($)	Apr. 02, 2023 USD ($)	Jan. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Jul. 03, 2022 USD ($)	Apr. 03, 2022 USD ($)	Jan. 02, 2022 USD ($)	Oct. 01, 2023 USD ($) fund	Oct. 02, 2022 USD ($)
Schedule of Investments [Line Items]
Marketable equity securities			$ 6,000			$ 26,000					$ 6,000
Strategic equity investments, without readily determinable fair values			28,000			28,000					28,000
Total revenue			1,119,000				$ 1,115,000				3,382,000	$ 3,501,000
(Gain) loss on Helix contingent value right											8,000	(8,000)
Accumulated other comprehensive income			21,000			3,000					21,000
GRAIL Inc
Schedule of Investments [Line Items]
Contingent value right, terms (in years)	12 years
Covered revenues of GRAIL, contingent consideration liability				$ 65,000	$ 65,000	65,000		$ 32,000	$ 32,000	$ 32,000
Payment for contingent consideration											609	297
Contingent consideration liabilities			330,000			412,000					330,000
Contingent consideration, noncurrent			329,000			411,000					329,000
GRAIL Inc \| Payment Rights Of One Billion, Each Twelve Years
Schedule of Investments [Line Items]
Contingent payment rights (as a percent)	2.50%
Business acquisition, contingent value rights, revenue threshold	$ 1,000,000
GRAIL Inc \| Payment Rights Of Above One Billion, Each Twelve Years
Schedule of Investments [Line Items]
Business acquisition, contingent value rights, revenue threshold	$ 1,000,000
Contingent payment rights, second percentage (as a percent)	9%
Helix Holdings I, LLC
Schedule of Investments [Line Items]
Contingent value right, terms (in years)		7 years
(Gain) loss on Helix contingent value right			(5,000)				(5,000)				$ 8,000	(8,000)
Venture Capital Investment Fund (the Fund)
Schedule of Investments [Line Items]
Number of venture capital investment funds \| fund											2
Equity method investments			165,000			$ 183,000					$ 165,000
Unrealized (loss) gain on investments			(19,000)				(5,000)				(33,000)	(11,000)
Venture Capital Investment Fund (the Fund), One
Schedule of Investments [Line Items]
Commitment in new venture capital investment fund			100,000								100,000
Remaining capital commitment			5,000								5,000
Venture Capital Investment Fund (the Fund), Two
Schedule of Investments [Line Items]
Commitment in new venture capital investment fund			150,000								150,000
Remaining capital commitment			74,000								74,000
Investee
Schedule of Investments [Line Items]
Total revenue			$ 2,000				$ 27,000				$ 68,000	$ 83,000

Investments and Fair Value Me_4

Investments and Fair Value Measurements - Schedule of Marketable Equity Securities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Fair Value Disclosures [Abstract]
Net gains (losses) recognized during the period on marketable equity securities	$ 0	$ 3	$ (2)	$ (66)
Less: Net losses recognized during the period on marketable equity securities sold during the period	0	0	(2)	0
Net unrealized gains (losses) recognized during the period on marketable equity securities still held at the reporting date	$ 0	$ 3	$ 0	$ (66)

Investments and Fair Value Me_5

Investments and Fair Value Measurements - Fair Value Hierarchy of Assets and Liabilities (Details) - USD ($) $ in Millions	Oct. 01, 2023	Jan. 01, 2023
Assets:
Marketable equity securities	$ 6	$ 26
Fair Value, Measurements, Recurring
Assets:
Money market funds (cash equivalents)	646	1,642
Marketable equity securities	6	26
Helix contingent value right	66	58
Deferred compensation plan assets	57	52
Total assets measured at fair value	775	1,778
Liabilities:
Contingent consideration liabilities	330	412
Deferred compensation plan liability	54	51
Total liabilities measured at fair value	384	463
Fair Value, Measurements, Recurring \| Level 1
Assets:
Money market funds (cash equivalents)	646	1,642
Marketable equity securities	6	26
Helix contingent value right	0	0
Deferred compensation plan assets	0	0
Total assets measured at fair value	652	1,668
Liabilities:
Contingent consideration liabilities	0	0
Deferred compensation plan liability	0	0
Total liabilities measured at fair value	0	0
Fair Value, Measurements, Recurring \| Level 2
Assets:
Money market funds (cash equivalents)	0	0
Marketable equity securities	0	0
Helix contingent value right	0	0
Deferred compensation plan assets	57	52
Total assets measured at fair value	57	52
Liabilities:
Contingent consideration liabilities	0	0
Deferred compensation plan liability	54	51
Total liabilities measured at fair value	54	51
Fair Value, Measurements, Recurring \| Level 3
Assets:
Money market funds (cash equivalents)	0	0
Marketable equity securities	0	0
Helix contingent value right	66	58
Deferred compensation plan assets	0	0
Total assets measured at fair value	66	58
Liabilities:
Contingent consideration liabilities	330	412
Deferred compensation plan liability	0	0
Total liabilities measured at fair value	$ 330	$ 412

Investments and Fair Value Me_6

Investments and Fair Value Measurements - Changes in Estimated Fair Value of Acquisition Related Contingent Consideration Liabilities (Details) - Business Combination Contingent Consideration Liability $ in Millions	9 Months Ended
	Oct. 01, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 412
Change in estimated fair value	(82)
Ending balance	$ 330

Debt - Summary of Term Debt Obl

Debt - Summary of Term Debt Obligations (Details) - Term Notes - USD ($)	Oct. 01, 2023	Jan. 01, 2023	Dec. 13, 2022	Mar. 23, 2021
Debt Instrument [Line Items]
Unamortized discounts and debt issuance costs	$ (11,000,000)	$ (13,000,000)
Net carrying amount of term notes	1,489,000,000	1,987,000,000
Less: current portion	0	(500,000,000)
Term notes, non-current	1,489,000,000	1,487,000,000
Level 2
Debt Instrument [Line Items]
Fair value of term notes outstanding (Level 2)	1,375,000,000	1,913,000,000
2031 Term Notes
Debt Instrument [Line Items]
Principal amount outstanding	500,000,000	500,000,000		$ 500,000,000
2027 Term Notes
Debt Instrument [Line Items]
Principal amount outstanding	500,000,000	500,000,000	$ 500,000,000
2025 Term Notes
Debt Instrument [Line Items]
Principal amount outstanding	500,000,000	500,000,000	$ 500,000,000
2023 Term Notes
Debt Instrument [Line Items]
Principal amount outstanding	$ 0	$ 500,000,000		$ 500,000,000

Debt - Narrative (Details)

Debt - Narrative (Details)		1 Months Ended	3 Months Ended		9 Months Ended
Debt - Narrative (Details)	Jan. 04, 2023 USD ($) consecutive_fiscal_quarter one_year_extension	Aug. 31, 2018 USD ($)	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Jan. 01, 2023 USD ($)	Dec. 13, 2022 USD ($)	Mar. 23, 2021 USD ($)
Term Notes
Debt Instrument [Line Items]
Interest expense recognized			$ 18,000,000	$ 4,000,000	$ 55,000,000	$ 13,000,000
Redemption price (as a percent)					100%
2023 Term Notes \| Term Notes
Debt Instrument [Line Items]
Stated rate (as a percent)									0.55%
Principal amount outstanding			0		$ 0		$ 500,000,000		$ 500,000,000
2031 Term Notes \| Term Notes
Debt Instrument [Line Items]
Stated rate (as a percent)									2.55%
Principal amount outstanding			500,000,000		500,000,000		500,000,000		$ 500,000,000
2025 Term Notes \| Term Notes
Debt Instrument [Line Items]
Stated rate (as a percent)								5.80%
Principal amount outstanding			500,000,000		500,000,000		500,000,000	$ 500,000,000
2027 Term Notes \| Term Notes
Debt Instrument [Line Items]
Stated rate (as a percent)								5.75%
Principal amount outstanding			$ 500,000,000		$ 500,000,000		$ 500,000,000	$ 500,000,000
2023 Convertible Notes \| Convertible Senior Notes
Debt Instrument [Line Items]
Stated rate (as a percent)			0%		0%
Principal amount outstanding		$ 750,000,000
Debt conversion ratio		0.0021845
The Credit Agreement \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 750,000,000
The Credit Agreement \| Line of Credit \| Swingline Borrowings
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 40,000,000
Number of one year extension, credit facility \| one_year_extension	2
One year extension, credit facility	1 year
Debt instrument term (in years)	5 years
The Credit Agreement \| Line of Credit \| Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 50,000,000
The Credit Agreement \| Unsecured Debt
Debt Instrument [Line Items]
Debt instrument, face amount, optional increase in additional borrowings	$ 250,000,000
Number of consecutive fiscal quarters, minimum debt to EBITDA ratio \| consecutive_fiscal_quarter	4
Debt instrument, covenant, minimum debt to EBITDA ratio	3.50
Debt instrument, covenant, minimum debt to EBITDA ratio upon consummation of acquisition	4
Number of consecutive fiscal quarters, minimum debt to EBITDA ratio upon consummation of acquisition \| consecutive_fiscal_quarter	3
The Credit Agreement \| Unsecured Debt \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Credit spread adjustment rate (as a percent)	0.10%

Debt - Summary of Convertible D

Debt - Summary of Convertible Debt Obligations (Details) - 2023 Convertible Notes - Convertible Senior Notes - USD ($)	Oct. 01, 2023	Aug. 31, 2018
Debt Instrument [Line Items]
Stated rate (as a percent)	0%
Principal amount outstanding		$ 750,000,000

Stockholders_ Equity - Narrativ

Stockholders’ Equity - Narrative (Details) shares in Thousands	9 Months Ended
	Oct. 01, 2023 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized	8,000
Liability-Classified RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	557,000
Market-Based PSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation vesting performance period (in years)	3 years
Granted award (as a percent)	175%
Granted (in shares)	119
2015 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance (in shares)	8,200

Stockholders_ Equity - Summary

Stockholders’ Equity - Summary of Restricted Stock Activity and Related Information (Details) shares in Thousands	9 Months Ended
	Oct. 01, 2023 $ / shares shares
Restricted Stock Units (RSUs)
Stock Units
Outstanding at period start (in shares) \| shares	1,611,000
Awarded (in shares) \| shares	2,000,000
Vested (in shares) \| shares	(118,000)
Cancelled (in shares) \| shares	(411,000)
Outstanding at period end (in shares) \| shares	3,082,000
Weighted-Average Grant Date Fair Value per Share
Outstanding at period start (in dollars per share) \| $ / shares	$ 311.23
Awarded (in dollars per share) \| $ / shares	197.09
Vested (in dollars per share) \| $ / shares	296.25
Cancelled (in dollars per share) \| $ / shares	255.53
Outstanding at period end (in dollars per share) \| $ / shares	$ 245.37
Performance Stock Units (PSU)
Stock Units
Outstanding at period start (in shares) \| shares	74
Awarded (in shares) \| shares	62
Vested (in shares) \| shares	0
Cancelled (in shares) \| shares	(96)
Outstanding at period end (in shares) \| shares	40
Weighted-Average Grant Date Fair Value per Share
Outstanding at period start (in dollars per share) \| $ / shares	$ 446.74
Awarded (in dollars per share) \| $ / shares	245.08
Vested (in dollars per share) \| $ / shares	0
Cancelled (in dollars per share) \| $ / shares	300.09
Outstanding at period end (in dollars per share) \| $ / shares	$ 198.25

Stockholders_ Equity - Summar_2

Stockholders’ Equity - Summary of Stock Option Activity Under all Stock Option Plans (Details) shares in Thousands	9 Months Ended
	Oct. 01, 2023 $ / shares shares
Options
Options
Outstanding at period start (in shares) \| shares	187
Exercised (in shares) \| shares	(8)
Cancelled (in shares) \| shares	(135)
Outstanding at period end (in shares) \| shares	44
Exercisable at period end (in shares) \| shares	18
Weighted-Average Exercise Price
Outstanding at period start (in dollars per share) \| $ / shares	$ 319.72
Exercised (in dollars per share) \| $ / shares	71.09
Cancelled (in dollars per share) \| $ / shares	330.25
Outstanding at period end (in dollars per share) \| $ / shares	330.25
Exercisable at period end (in dollars per share) \| $ / shares	$ 330.25
Performance stock options
Options
Outstanding at period start (in shares) \| shares	17
Exercised (in shares) \| shares	(1)
Cancelled (in shares) \| shares	0
Outstanding at period end (in shares) \| shares	16
Exercisable at period end (in shares) \| shares	0
Weighted-Average Exercise Price
Outstanding at period start (in dollars per share) \| $ / shares	$ 85.54
Exercised (in dollars per share) \| $ / shares	16.69
Cancelled (in dollars per share) \| $ / shares	0
Outstanding at period end (in dollars per share) \| $ / shares	87.74
Exercisable at period end (in dollars per share) \| $ / shares	$ 0

Stockholders_ Equity - Narrat_2

Stockholders’ Equity - Narrative - Other Liability - Classified Awards (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before taxes	$ 86	$ 83	$ 286	$ 266
Unrecognized compensation cost	582		$ 582
Weighted-average period of unrecognized compensation cost (in years)			2 years 4 months 24 days
Liability-Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation vesting performance period (in years)			4 years
Share-based compensation expense before taxes	26	$ 17	$ 72	$ 46
Unrecognized compensation cost	266		$ 266
Weighted-average period of unrecognized compensation cost (in years)			2 years 9 months 18 days
Aggregated potential value	$ 78		$ 78

Stockholders_ Equity - Other Li

Stockholders’ Equity - Other Liability - Classified Awards (Details) - USD ($) $ in Millions	9 Months Ended
	Oct. 01, 2023	Jan. 01, 2023
Share-Based Compensation Arrangement By Share-Based Payment Award Liability-Classified Awards, Outstanding [Roll Forward]
Liability-classified equity incentive awards	$ 42	$ 36
Liability-Based Awards
Share-Based Compensation Arrangement By Share-Based Payment Award Liability-Classified Awards, Outstanding [Roll Forward]
Estimated liability, Beginning balance	293
Granted	116
Vested and paid in cash	(65)
Cancelled	(28)
Change in fair value	(8)
Estimated liability, Ending balance	308
Liability-classified equity incentive awards	$ 42

Stockholders_ Equity - Narrat_3

Stockholders’ Equity - Narrative - Employee Stock Purchase Plan (Details) - ESPP - Employee Stock shares in Millions	9 Months Ended
	Oct. 01, 2023 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Specified percentage of the fair market value of the common stock on the first or last day of the offering period whichever is lower at which stock is purchased (as a percent)	85%
Total shares issued under the ESPP (in shares)	0.4
Shares available for issuance (in shares)	12.4

Stockholders_ Equity- Summary o

Stockholders’ Equity- Summary of Assumptions Used to Estimate the Weighted Average Fair Value Per Share (Details) - Employee Stock	9 Months Ended
	Oct. 01, 2023 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate minimum (as a percent)	0.78%
Risk free interest rate maximum (as a percent)	5.54%
Expected volatility, minimum (as a percent)	41%
Expected volatility, maximum (as a percent)	51%
Expected dividends	0%
Weighted-average fair value per share (in dollars per share)	$ 49.87
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	1 year 1 month 6 days

Stockholders_ Equity - Narrat_4

Stockholders’ Equity - Narrative - Share Repurchases (Details) - Common Stock - USD ($)	9 Months Ended
	Oct. 01, 2023	Feb. 05, 2020
Class of Stock [Line Items]
Repurchased common stock (in shares)	0
Dollar amount remaining in authorized stock repurchase program	$ 15,000,000
Stock repurchase program, authorized amount		$ 750,000,000

Stockholders_ Equity - Summar_3

Stockholders’ Equity - Summary of Share-based Compensation Expense for all Stock Awards (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before taxes	$ 86	$ 83	$ 286	$ 266
Related income tax benefits	(19)	(18)	(65)	(60)
Share-based compensation expense, net of taxes	67	65	221	206
Cost of product revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before taxes	7	7	22	20
Cost of service and other revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before taxes	2	2	5	4
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before taxes	36	37	117	112
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before taxes	$ 41	$ 37	$ 142	$ 130

Supplemental Balance Sheet De_3

Supplemental Balance Sheet Details - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Oct. 01, 2023	Jan. 01, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Trade accounts receivable, gross	$ 696	$ 675
Allowance for credit losses	(6)	(4)
Total accounts receivable, net	$ 690	$ 671

Supplemental Balance Sheet De_4

Supplemental Balance Sheet Details - Summary of Inventory (Details) - USD ($) $ in Millions	Oct. 01, 2023	Jan. 01, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 278	$ 247
Work in process	423	386
Finished goods	35	28
Inventory, gross	736	661
Inventory reserve	(121)	(93)
Total inventory, net	$ 615	$ 568

Supplemental Balance Sheet De_5

Supplemental Balance Sheet Details - Summary of Accrued Liabilities (Details) - USD ($) $ in Millions	Oct. 01, 2023	Jan. 01, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Legal contingencies	$ 458	$ 473
Contract liabilities, current portion	242	245
Accrued compensation expenses	195	188
Accrued taxes payable	65	97
Operating lease liabilities, current portion	85	76
Liability-classified equity incentive awards	42	36
Other, including warranties	155	117
Total accrued liabilities	$ 1,242	$ 1,232

Supplemental Balance Sheet De_6

Supplemental Balance Sheet Details - Summary of Changes in Reserve for Product Warranties (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Reserve for product warranties [Roll Forward]
Balance at beginning of period	$ 20	$ 21	$ 18	$ 22
Additions charged to cost of product revenue	10	5	30	17
Repairs and replacements	(11)	(7)	(29)	(20)
Balance at end of period	$ 19	$ 19	$ 19	$ 19

Supplemental Balance Sheet De_7

Supplemental Balance Sheet Details - Pre-Tax Restructuring Charge (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Oct. 01, 2023	Oct. 01, 2023
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 58	$ 91
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	55	74
Research and development
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	2	13
Employee separation costs
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	7	33
Asset impairment charges
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	49	56
Other Costs
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 2	$ 2

Supplemental Balance Sheet De_8

Supplemental Balance Sheet Details - Narrative - Restructuring (Details) $ in Millions	3 Months Ended	9 Months Ended
	Oct. 01, 2023 USD ($)	Oct. 01, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Right-of-use asset impairment	$ 33	$ 38
CALIFORNIA
Restructuring Cost and Reserve [Line Items]
Right-of-use assets and leasehold improvements	182	182
Leasehold improvements
Restructuring Cost and Reserve [Line Items]
Right-of-use asset impairment	$ 14	$ 16

Supplemental Balance Sheet De_9

Supplemental Balance Sheet Details - Pre-Tax Charges and Total Costs (Details) $ in Millions	9 Months Ended
	Oct. 01, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Expense recorded in YTD 2023	$ 35
Cash paid during YTD 2023	(31)
Amount recorded in accrued liabilities as of October 1, 2023	4
Estimated total restructuring costs to still be incurred	2
Employee separation costs
Restructuring Cost and Reserve [Line Items]
Expense recorded in YTD 2023	33
Cash paid during YTD 2023	(30)
Amount recorded in accrued liabilities as of October 1, 2023	3
Estimated total restructuring costs to still be incurred	2
Other Costs
Restructuring Cost and Reserve [Line Items]
Expense recorded in YTD 2023	2
Cash paid during YTD 2023	(1)
Amount recorded in accrued liabilities as of October 1, 2023	1
Estimated total restructuring costs to still be incurred	$ 0

Supplemental Balance Sheet D_10

Supplemental Balance Sheet Details - Narrative - Warranties (Details)	9 Months Ended
	Oct. 01, 2023
Instruments
Product Warranty Liability [Line Items]
Warranty period (in months)	1 year
Consumables \| Minimum
Product Warranty Liability [Line Items]
Warranty period (in months)	6 months
Consumables \| Maximum
Product Warranty Liability [Line Items]
Warranty period (in months)	12 months

Supplemental Balance Sheet D_11

Supplemental Balance Sheet Details - Narrative - Goodwill and Intangible Assets (Details) $ in Millions	1 Months Ended	3 Months Ended			9 Months Ended
	Nov. 06, 2023	Oct. 01, 2023 USD ($)	Jul. 02, 2023 unit	Oct. 02, 2022 USD ($)	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Jan. 01, 2023 USD ($)
Indefinite-lived Intangible Assets [Line Items]
Number of reporting units \| unit			2
Impairment		$ (821)		$ (3,914)	$ (821)	$ (3,914)
Goodwill		2,527			$ 2,527		$ 3,239
Subsequent Event
Indefinite-lived Intangible Assets [Line Items]
Decline in share price (in percent)	0.18
In-process research and development (IPR&D)
Indefinite-lived Intangible Assets [Line Items]
Fair value of discount rate (as a percent)					19%
Goodwill fair value recorded impairment		109
Goodwill carrying value		561			$ 561
Core Illumina
Indefinite-lived Intangible Assets [Line Items]
Fair value in excess of carrying amount (more than)		20,000			20,000
GRAIL
Indefinite-lived Intangible Assets [Line Items]
Impairment				$ (3,914)	$ (712)
Fair value of discount rate (as a percent)					24%
Goodwill		$ 1,466			$ 1,466
GRAIL \| Minimum
Indefinite-lived Intangible Assets [Line Items]
Fair value of discount rate (as a percent)					0.50%
Goodwill impairment loss upon increase in discount rate					$ 200
GRAIL \| Maximum
Indefinite-lived Intangible Assets [Line Items]
Fair value of discount rate (as a percent)					1%
Goodwill impairment loss upon increase in discount rate					$ 350

Supplemental Balance Sheet D_12

Supplemental Balance Sheet Details - Changes to Goodwill (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Indefinite-lived Intangible Assets [Line Items]
Goodwill and intangible impairment	$ 821	$ 3,914	$ 821	$ 3,914
Goodwill [Roll Forward]
Goodwill, beginning balance			3,239
Impairment	(821)	(3,914)	(821)	$ (3,914)
Goodwill, ending balance	2,527		2,527
GRAIL
Indefinite-lived Intangible Assets [Line Items]
Goodwill and intangible impairment		3,914	712
Goodwill [Roll Forward]
Impairment		$ (3,914)	(712)
Goodwill, ending balance	$ 1,466		$ 1,466

Supplemental Balance Sheet D_13

Supplemental Balance Sheet Details - Narrative - Derivatives (Details) € in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Jul. 12, 2023 EUR (€)	Jan. 01, 2023 USD ($)
Derivative [Line Items]
Reclassification to revenue	$ 5	$ 16	$ 9	$ 32
Estimated net gains reported in accumulated other comprehensive income	22		22
GRAIL
Derivative [Line Items]
Loss contingency accrual \| €					€ 432
Foreign Exchange Forward
Derivative [Line Items]
Foreign currency forward contracts assets	27		27
Foreign currency forward contracts liabilities	1		$ 1
Derivative asset, current amount						$ 8
Derivative liability, current amount						6
Foreign Exchange Forward \| Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative, term of contract (in months)			1 month
Derivative, notional amount	912		$ 912			485
Foreign Exchange Forward \| Designated as Hedging Instrument
Derivative [Line Items]
Derivative, term of contract (in months)			24 months
Derivative, notional amount	$ 663		$ 663			$ 425

Legal Proceedings (Details)

Legal Proceedings (Details) € in Millions, $ in Millions	12 Months Ended
Legal Proceedings (Details) € in Millions, $ in Millions	Jan. 01, 2023 USD ($)	Oct. 01, 2023 USD ($)	Jul. 12, 2023 EUR (€)
Loss Contingencies [Line Items]
Legal contingencies \| $	$ 473	$ 458
GRAIL
Loss Contingencies [Line Items]
Loss contingency accrual \| €			€ 432
Potential fine as a percent of consolidated annual revenues	0.10
Long-term debt, fine percentage rate		0.055

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022	Jan. 01, 2023
Income Tax Examination [Line Items]
Effective tax rate (as a percent)	3.60%	(4.00%)	(3.80%)	(2.30%)
Income tax expense			$ 149
Impact on tax rate due to capitalization of research and development expenses	$ 20		84
Impact on tax rate due to GILTI and U.S. foreign tax credits	38
Foreign income tax expense (benefit)			63
Income tax receivable	$ 78		$ 78		$ 116
US
Income Tax Examination [Line Items]
Effective tax rate (as a percent)	21%		21%

Segment Information - Summary o

Segment Information - Summary of Operating Performance and Assets by Segment (Details) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Oct. 01, 2023 USD ($) segment	Oct. 02, 2022 USD ($)
Segment Reporting [Abstract]
Number of reportable segments \| segment			2
Segment Reporting Information [Line Items]
Consolidated revenue	$ 1,119	$ 1,115	$ 3,382	$ 3,501
Consolidated loss from operations	(754)	(3,657)	(905)	(4,052)
Operating Segments \| Core Illumina
Segment Reporting Information [Line Items]
Consolidated revenue	1,106	1,110	3,341	3,487
Consolidated loss from operations	262	445	519	411
Operating Segments \| GRAIL
Segment Reporting Information [Line Items]
Consolidated revenue	21	10	62	32
Consolidated loss from operations	(1,015)	(4,101)	(1,424)	(4,460)
Eliminations
Segment Reporting Information [Line Items]
Consolidated revenue	(8)	(5)	(21)	(18)
Consolidated loss from operations	$ (1)	$ (1)	$ 0	$ (3)