MASIMO CORP — Director's Dealing 2026

Mar 3, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MASIMO CORP (MASI)
CIK: 0000937556
Period of Report: 2026-02-27

Reporting Person: Young Micah W (EVP & Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-02-27	Common Stock	A	15000	—	Acquired	33347	Direct
2026-02-27	Common Stock	F	8093	$175.35	Disposed	25254	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-02-27	Restricted Stock Units	$	M	15000	Disposed		Common Stock (15000)	Direct

Footnotes

F1: As previously reported, the reporting person was granted 30,000 restricted stock units on March 1, 2024, 50% of which vested on March 1, 2025. The remaining 15,000 restricted stock units vested on February 27, 2026.

F2: For the vesting that occurred on March 1, 2026, the Issuer calculated the number of vested shares and shares withheld for tax liability based on its closing stock price on the immediately preceding business day. As a result, the Reporting person received 6,907 shares of common stock, as shown in Table I.

F3: 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 restricted stock units.

F4: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of the Issuer upon vesting of the RSU.