Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Politan Capital Management LP 2. Issuer Name and Ticker or Trading Symbol MASIMO CORP [MASI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) Director by deputization (Last) (First) (Middle) 106 WEST 56TH STREET, 10TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 06/10/2026 (Street) NEW YORK, NY 10019 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 06/10/2026 D 4,590,873 D $180(1)(2) 0 I See footnotes(3)(4)(5)(6)(7)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Units

(9)

06/10/2026

D

1,119

(1)(8)(9)

(1)(8)(9)

Common Stock

1,119

(8)

0

I

See footnotes(10)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Politan Capital Management LP 106 WEST 56TH STREET, 10TH FLOOR NEW YORK, NY 10019				Director by deputization
Koffey Quentin 106 WEST 56TH STREET, 10TH FLOOR NEW YORK, NY 10019				Director by deputization
Politan Capital Partners GP LLC 106 WEST 56TH STREET, 10TH FLOOR NEW YORK, NY 10019				Director by deputization
Politan Capital Management GP LLC 106 WEST 56TH STREET, 10TH FLOOR NEW YORK, NY 10019				Director by deputization

Signatures

Politan Capital Management LP By: Politan Capital Management GP LLC, its General Partner /s/ Quentin Koffey, Managing Member		06/12/2026
**Signature of Reporting Person		Date
Politan Capital Management GP LLC /s/ Quentin Koffey, Managing Member		06/12/2026
**Signature of Reporting Person		Date
Politan Capital Partners GP LLC /s/ Quentin Koffey, Managing Member		06/12/2026
**Signature of Reporting Person		Date
/s/ Quentin Koffey		06/12/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	On June 10, 2026, pursuant to the Agreement and Plan of Merger, dated as of February 16, 2026, by and among Masimo Corporation (the "Issuer"), Danaher Corporation ("Parent") and Mobius Merger Sub, Inc. ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent.
(2)	At the effective time of the Merger, each share of the Issuer's common stock, par value $0.001 per share (the "Common Stock") issued and outstanding immediately prior to the effective time (other than certain excluded and dissenting shares) was canceled and converted into the right to receive $180.00 in cash, without interest (the "Per Share Merger Consideration").
(3)	This Form 4 is being filed jointly by Politan Capital Management LP, a Delaware limited partnership ("Politan"), Politan Capital Management GP LLC, a Delaware limited liability company ("Politan Management"), Politan Capital Partners GP LLC, a Delaware limited liability company ("Politan GP"), and Quentin Koffey, a citizen of the United States of America (collectively, the "Reporting Persons"), each of whom has the same business address as Politan and may be deemed to have a pecuniary interest in the securities reported on this Form 4 (the "Subject Securities").
(4)	Politan is the investment advisor to certain funds, including Politan Capital Partners LP, a Delaware limited partnership ("Politan LP"), Politan Capital Offshore Partners LP, a Cayman Islands exempted limited partnership ("Politan Offshore"), and Politan Capital Partners Master Fund LP, a Cayman Islands exempted limited partnership ("Politan Master Fund" and, collectively with Politan LP and Politan Offshore, the "Politan Funds").
(5)	Politan, as the investment advisor of the Politan Funds, may be deemed to be the beneficial owner of the Subject Securities for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934. As the general partner of Politan, Politan Management may be deemed to be the beneficial owner of the Subject Securities for purposes of Rule 16a-1(a). As the general partner of the Politan Funds, Politan GP may be deemed to be the beneficial owner of the Subject Securities for purposes of Rule 16a-1(a).
(6)	By virtue of Mr. Koffey's position as managing partner and chief investment officer of Politan, and as the managing member of Politan Management and Politan GP, Mr. Koffey may be deemed to be the beneficial owner of the Subject Securities for purposes of Rule 16a-1(a). Each of the Reporting Persons disclaims beneficial ownership of the Subject Securities, except to the extent of any pecuniary interest therein.
(7)	Mr. Koffey is a member of the board of directors of the Issuer, and as a result, each of the other Reporting Persons may be directors by deputization for purposes of Section 16 of the Securities Exchange Act of 1934.
(8)	On June 10, 2026, at the effective time of the Merger, each of the Issuer's restricted stock units ("RSUs") held by the Issuer's non-employee directors was canceled and converted into the right to receive an amount in cash equal to the Per Share Merger Consideration.
(9)	Represents the unvested portion of RSUs granted on April 23, 2026, which award of RSUs was to vest on the earlier of the first anniversary of the grant date or the next annual meeting of stockholders following the date of grant.
(10)	These RSUs are held directly by Mr. Koffey.

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