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): April 29, 2025

MASIMO CORPORATION

(Exact name of registrant as specified in its charter)

52 Discovery
Irvine, CA 92618

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (949) 297-7000

Not Applicable

(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:

Securities registered pursuant to Section 12(b) of the Act:

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 13(a) of the Exchange Act. ¨

The Company held its annual meeting of the stockholders (the “Annual Meeting”) on April 29, 2025. At the Annual Meeting, a total of 50,760,206 shares, or approximately 93.93% of the Company’s common stock issued and outstanding as of the record date, were represented in person or by proxy. At the Annual Meeting, the Company’s stockholders considered three proposals, each of which is described in more detail in the Company’s definitive proxy statement filed with the Securities and Exchange Commission on March 26, 2025 (the “Proxy Statement”).

On April 29, 2025, American Election Services, LLC. (the “Inspector of Election”) issued its final report, which certified the final voting results for the Annual Meeting. Set forth below is a brief description of each matter voted upon at the Annual Meeting, which are more fully described in the Proxy Statement, and the final voting results with respect to each matter as provided by the Inspector of Election.

Proposal No. 1: To elect three Class II and two Class III nominees for director to serve until the Company’s 2026 Annual Meeting of Stockholders, or until his or her respective successor is duly elected and qualified.

The Company’s stockholders voted to elect William Jellison, Wendy Lane, Timothy Scannell, Darlene Solomon and Catherine Szyman as directors to serve until the Company’s 2026 Annual Meeting of Stockholders, or until his or her respective successor is duly elected and qualified.

Proposal No. 2: To ratify the selection of Grant Thornton LLP as the Company’s independent registered public accounting firm for the fiscal year ending January 3, 2026.

The Company’s stockholders voted to approve the ratification of the selection of Grant Thornton LLP as the Company’s independent registered public accounting firm.

Proposal No. 3: To provide an advisory vote to approve the compensation of the Company’s named executive officers.

The Company’s stockholders voted for the advisory vote to approve the compensation of the Company’s named executive officers.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, Masimo Corporation has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.