Catherine M. Szyman - 12 Feb 2026 Form 4 Insider Report for MASIMO CORP (MASI)

Role: CEO, Director
Signature: /s/ Micah W. Young, Attorney-In-Fact
Issuer symbol: MASI
Transactions as of: 12 Feb 2026
Net transactions value: +$1,481,307
Form type: 4
Filing time: 13 Feb 2026, 17:28:49 UTC
Previous filing: 13 Mar 2025
Next filing: 10 Mar 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Szyman Catherine M.	CEO, Director	C/O MASIMO CORPORATION, 52 DISCOVERY, IRVINE	/s/ Micah W. Young, Attorney-In-Fact	13 Feb 2026	0001438538

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MASI	Common Stock	Options Exercise	$1,481,307	+11,141		$132.96	11,141	12 Feb 2026	Direct
transaction	MASI	Common Stock	Tax liability	$0	-4,568	-41%	$0.000000	6,573	12 Feb 2026	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	MASI	Restricted Stock Units	Options Exercise	$0	-11,141	-33%	$0.000000	22,283	12 Feb 2026	Common Stock	11,141		Direct	F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	These shares were withheld by the Issuer in order to satisfy certain tax withholding obligations in connection with the issuance of shares upon the vesting of certain performance restricted stock units.
F2	Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of the Issuer upon vesting of the RSU.
F3	As previously reported, the reporting person was granted 33,424 RSUs on February 12, 2025 and will vest ratably over three years. One-third of the RSUs vested on February 12, 2026, and the remaining RSUs will vest in two equal installments on the second and third anniversaries of the grant date.