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 * Szyman Catherine M. 2. Issuer Name and Ticker or Trading Symbol MASIMO CORP [MASI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Executive Officer (Last) (First) (Middle) C/O MASIMO CORPORATION, 52 DISCOVERY 3. Date of Earliest Transaction (Month/Day/Year) 06/10/2026 (Street) IRVINE, CA 92618 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ 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 7,605 D $180(1)(2) 0 D

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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	(4)	06/10/2026		D			22,283	(1)(3)(4)	(1)(3)(4)	Common Stock	22,283	(3)	0	D
Restricted Stock Units	(5)	06/10/2026		D			6,306	(1)(3)(5)	(1)(3)(5)	Common Stock	6,306	(3)	0	D
Restricted Stock Units	(6)	06/10/2026		D			39,904	(1)(3)(6)	(1)(3)(6)	Common Stock	39,904	(3)	0	D
Non-Qualified Stock Option (Right to Buy)	$166.52	06/10/2026		D			18,617	(1)(7)	(1)(7)	Common Stock	18,617	$13.48(7)	0	D
Performance-Based Restricted Stock Unit	(9)	06/10/2026		D			49,243	(1)(8)(9)	(1)(8)(9)	Common Stock	49,243	$180(8)	0	D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Szyman Catherine M. C/O MASIMO CORPORATION 52 DISCOVERY IRVINE, CA 92618	X		Chief Executive Officer

Signatures

/s/ Micah W. Young, Attorney-In-Fact		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 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, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent (the "Merger").
(2)	On June 10, 2026, 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 prior to the effective time of the Merger (other than certain excluded shares and dissenting shares) was canceled, extinguished and converted into the right to receive an amount in cash equal to $180.00 per share, without interest (the "Per Share Merger Consideration").
(3)	On June 10, 2026, at the effective time of the Merger, each of the Issuer's restricted stock units ("RSUs") (other than certain RSUs held by the Issuer's non-employee directors) was assumed by Parent and converted into a number of RSUs of Parent equal to the product of the number of shares of Parent common stock equal to the number of shares of Common Stock underlying such RSU multiplied by the quotient of (a) the Per Share Merger Consideration, divided by (b) the volume-weighted average trading price per share of Parent's common stock for the ten trading day period ending on and including June 10, 2026 ($183.33).
(4)	Represents the unvested portion of RSUs granted on February 12, 2025, which award of RSUs was to vest ratably over three years.
(5)	Represents the unvested portion of RSUs granted on March 11, 2025, which award of RSUs was to vest ratably over four years.
(6)	Represents the unvested portion of RSUs granted on March 6, 2026, which award of RSUs was to vest ratably over four years.
(7)	On June 10, 2026, at the effective time of the Merger, each of the Issuer's stock options outstanding as of immediately prior to the effective time of the Merger, whether vested or unvested, were canceled and converted into the right to receive, for each share of Common Stock subject to such option, the excess, if any, of the Per Share Merger Consideration over the exercise price per share of such option, without interest and less any applicable tax withholding.
(8)	On June 10, 2026, at the effective time of the Merger, each of the Issuer's performance-based restricted stock units ("PSUs") outstanding as of immediately prior to the effective time of the Merger, as determined at target performance, were canceled and converted into the right to receive $180.00 for each share of Common Stock underlying such award of PSUs, without interest and less any applicable tax withholding.
(9)	Represents the PSUs granted on March 11, 2025, which represented the right to receive shares of Common Stock over a three year performance period, determined at target performance.

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