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ilmn-202602050001110803FALSE2/5/202600011108032026-02-052026-02-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549 Form 8-K Current Report

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 5, 2026

Illumina, Inc. (Exact name of registrant as specified in its charter)

001-35406 (Commission File Number) Delaware 33-0804655 (State or other jurisdiction of incorporation) (I.R.S. Employer Identification No.)

5200 Illumina Way, San Diego, CA 92122 (Address of principal executive offices) (Zip code)

(858) 202-4500 (Registrant’s telephone number, including area code)

N/A (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐     Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐     Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐     Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐     Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par valueILMNThe Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13a of the Exchange Act. o

TABLE OF CONTENTS

Item 2.02 Results of Operations and Financial Condition Item 9.01 Financial Statements and Exhibits

SIGNATURES

Exhibit Index

Table of Contents

Item 2.02 Results of Operations and Financial Condition.

On February 5, 2026, Illumina, Inc. (the “Company”) issued a press release announcing financial results for the fourth quarter and fiscal year ended December 28, 2025. The full text of the Company’s press release is attached hereto as Exhibit 99.1.

The information furnished pursuant to this Item 2.02 (including Exhibit 99.1) shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities under that Section and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933 or the Exchange Act.

Table of Contents

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

99.1    Press release dated February 5, 2026, announcing Illumina, Inc.’s financial results for the fourth quarter and fiscal year ended December 28, 2025

104    Cover Page Interactive Data File (embedded within the Inline XBRL document)

Table of Contents

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

ILLUMINA, INC.

Date:February 5, 2026By:  /s/ ANKUR DHINGRA

Name:Ankur Dhingra Title:Chief Financial Officer

Table of Contents

Exhibit Index

Exhibit NumberDescription 99.1 Press release dated February 5, 2026 announcing Illumina, Inc.’s financial results for the fourth quarter and fiscal year ended December 28, 2025

104Cover Page Interactive Data File (embedded within the Inline XBRL document)

ilmn-202601130001110803FALSEJanuary 13, 202600011108032026-01-132026-01-13

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549 Form 8-K Current Report

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 13, 2026

Illumina, Inc. (Exact name of registrant as specified in its charter)

001-35406 (Commission File Number) Delaware 33-0804655 (State or other jurisdiction of incorporation) (I.R.S. Employer Identification No.)

5200 Illumina Way, San Diego, CA 92122 (Address of principal executive offices) (Zip code)

(858) 202-4500 (Registrant’s telephone number, including area code)

N/A (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐     Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐     Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐     Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐     Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par valueILMNThe NASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13a of the Exchange Act. o

TABLE OF CONTENTS

Item 2.02 Results of Operations and Financial Condition Item 9.01 Financial Statements and Exhibits

SIGNATURES

Exhibit Index

Table of Contents

Item 2.02 Results of Operations and Financial Condition.

On January 13, 2026, in advance of a public webcast presentation at the J.P. Morgan Healthcare Conference in San Francisco, California, Illumina, Inc. (the "Company") issued a press release regarding the Company's unaudited preliminary financial results for the fourth quarter and fiscal year ended December 28, 2025. The webcast is accessible through the Investor Relations section of the Company’s website and will remain available for at least 30 days following. Pursuant to General Instruction F to Form 8-K, a copy of the press release is attached hereto as Exhibit 99.1 and is incorporated into this Item 2.02 by this reference.

The information furnished pursuant to this Item 2.02 (including Exhibit 99.1) shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities under that Section and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933 or the Exchange Act.

Table of Contents

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

99.1    Press release dated January 13, 2026, announcing Illumina, Inc.’s preliminary unaudited financial results for the fourth quarter and fiscal year ended December 28, 2025 104    Cover Page Interactive Data File (embedded within the Inline XBRL document)

Table of Contents

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

ILLUMINA, INC.

Date:January 13, 2026 By:/s/ ANKUR DHINGRA

Name:Ankur Dhingra Title:Chief Financial Officer

Table of Contents

Exhibit Index

Exhibit NumberDescription 99.1 Press release dated January 13, 2026, announcing Illumina, Inc.’s preliminary unaudited financial results for the fourth quarter and fiscal year ended December 28, 2025

104Cover Page Interactive Data File (embedded within the Inline XBRL document)