Masimo (NASDAQ: MASI) board member William Jellison steps down

Rhea-AI Filing Summary

Masimo Corporation reported that William Jellison, a member of its Board of Directors, resigned from the Board effective August 18, 2025. The company stated that his resignation was not due to any disagreement with Masimo on matters related to its operations, policies, or practices, indicating this is not being characterized as a conflict-driven departure.

Board Chair Michelle Brennan thanked Mr. Jellison for his service and contributions during what she described as a transformative period for the company, and extended well wishes for his future endeavors. The filing also includes a technical exhibit for the cover page interactive data file, but no financial results or major transactions are discussed.

8-K Event Classification

2 items: 5.02, 9.01

2 items

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers Governance

Key personnel changes including departures, elections, or appointments of directors and executive officers.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

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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): August 18, 2025

MASIMO CORPORATION

(Exact name of registrant as specified in its charter)

________________________________________________

DE

001-33642

33-0368882

(State or other jurisdiction of incorporation)

(Commission File Number)

(IRS Employer Identification No.)

52 Discovery

Irvine,

CA

92618

(Address of Principal Executive Offices)

(Zip Code)

(949)

297-7000

Registrant’s telephone number, including area code:

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:
☐			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 class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.001 par value

MASI

The 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 13(a) of the Exchange Act.

☐

Item 5.02......Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On August 18, 2025, Mr. William Jellison, a member of the Board of Directors (the “Board”) of Masimo Corporation (the “Company”), notified the Company of his decision to resign from the Board effective that same date. Mr. Jellison’s resignation was not due to any disagreement with the Company on any matter relating to the Company’s operations, policies, or practices. Michelle Brennan, the Chairman of the Board, said, “We thank Mr. Jellison for his service and contributions during a transformative period for the Company and we wish him well in his future endeavors.”

Item 9.01. Financial Statements and Exhibits.

(d) The following items are filed as exhibits to the Current Report on Form 8-K.

Exhibit  No.			Description
104			Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

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.

MASIMO CORPORATION

Date: August 19, 2025

By:

/s/ MICAH YOUNG

Micah Young

Executive Vice President & Chief Financial Officer

(Principal Financial Officer)

FAQ

What board change did Masimo (MASI) disclose in this 8-K?

Masimo Corporation disclosed that William Jellison, a member of its Board of Directors, resigned from the Board effective August 18, 2025.

Did William Jellison resign from Masimo due to a disagreement with the company?

No. Masimo stated that Mr. Jellison’s resignation was not due to any disagreement with the company regarding its operations, policies, or practices.

What did Masimo’s Board Chair say about William Jellison’s resignation?

Michelle Brennan, the Chairman of the Board, thanked Mr. Jellison for his service and contributions during a transformative period for the company and wished him well in his future endeavors.

Does this Masimo (MASI) filing include financial results or earnings data?

No. This report focuses on the resignation of a Board member and does not include financial results or earnings data.

Who signed this Masimo 8-K on behalf of the company?

The report was signed by Micah Young, Executive Vice President & Chief Financial Officer, identified as the Principal Financial Officer of Masimo Corporation.

What exhibit was filed with this Masimo (MASI) 8-K?

Masimo included Exhibit 104, described as the Cover Page Interactive Data File embedded within the Inline XBRL document.