Masimo (MASI) CFO gets performance stock; 1,123 shares withheld for taxes

Rhea-AI Filing Summary

Masimo Corp executive Micah W. Young reported equity award activity involving company common stock. He acquired 2,034 shares at no cost in connection with the vesting of previously granted performance-based restricted stock units that vested upon achievement of three-year performance goals. To cover related tax withholding obligations, 1,123 shares were disposed of by being withheld by Masimo at a price of $175.22 per share, leaving him with 18,347 shares held directly after these transactions.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Young Micah W

Role EVP & Chief Financial Officer

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	2,034	$0.00	--
Tax Withholding	Common Stock	1,123	$175.22	$197K

Holdings After Transaction: Common Stock — 19,470 shares (Direct)

Footnotes (1)

1. On March 3, 2023, the Reporting Person was granted performance-based restricted stock units ("PSUs"), which vested on February 26, 2026 upon the Issuer's achievement of certain pre-established performance goals for the three-year performance period ended January 3, 2026. 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 PSUs.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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 for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Young Micah W

(Last) (First) (Middle)

C/O MASIMO CORPORATION

52 DISCOVERY

(Street)

IRVINE CA 92618

(City) (State) (Zip)

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
X	Officer (give title below)		Other (specify below)
	EVP & Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/26/2026

4. If Amendment, Date of 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

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	02/26/2026		A		2,034(1)	A	$0	19,470	D
Common Stock	02/26/2026		F		1,123(2)	D	$175.22	18,347	D

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 Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. On March 3, 2023, the Reporting Person was granted performance-based restricted stock units ("PSUs"), which vested on February 26, 2026 upon the Issuer's achievement of certain pre-established performance goals for the three-year performance period ended January 3, 2026.

2. 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 PSUs.

Remarks:

	/s/ Micah W. Young, Attorney-In-Fact	02/26/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did Masimo (MASI) CFO Micah W. Young report?

Masimo CFO Micah W. Young reported receiving 2,034 common shares through a vested performance-based stock award. In the same filing, 1,123 shares were withheld by Masimo to satisfy tax obligations tied to that vesting, leaving him with 18,347 directly held shares.

Were Masimo (MASI) shares bought or sold on the open market in this Form 4?

The Form 4 shows no open-market buying or selling. Shares were acquired via a vested performance-based restricted stock unit award, and a portion was disposed of through tax withholding, where Masimo withheld 1,123 shares to cover tax liabilities, not via market sales.

How many Masimo (MASI) shares did the CFO receive from performance-based awards?

The CFO received 2,034 Masimo common shares at no cost upon vesting of performance-based restricted stock units. These units were originally granted in March 2023 and vested after Masimo achieved specified performance goals over a three-year performance period ending January 3, 2026.

Why were 1,123 Masimo (MASI) shares disposed of in the Form 4 filing?

The 1,123 shares were disposed of solely to meet tax withholding obligations tied to the PSU vesting. Masimo withheld these shares at $175.22 per share instead of the executive selling shares in the market, a common method to satisfy income and payroll tax requirements.

What is Micah W. Young’s Masimo (MASI) share ownership after these transactions?

After the reported award and tax-withholding disposition, Micah W. Young directly owns 18,347 Masimo common shares. This balance reflects the 2,034-share PSU vesting credited to him and the 1,123 shares withheld by Masimo to cover associated tax liabilities.

What performance conditions were tied to the Masimo (MASI) PSUs that vested?

The PSUs were granted on March 3, 2023 and vested upon Masimo’s achievement of pre-established performance goals. These goals were measured over a three-year performance period that ended January 3, 2026, triggering issuance of 2,034 common shares to the CFO upon vesting.