Masimo (MASI) CEO converts RSUs and withholds shares to cover taxes

Rhea-AI Filing Summary

Masimo Corporation CEO Catherine M. Szyman reported equity compensation activity on February 12, 2026. She exercised 11,141 restricted stock units (RSUs), converting them into 11,141 shares of common stock at a price of $132.96 per share. Of these, 4,568 shares were withheld by Masimo to cover tax withholding obligations tied to the vesting of performance RSUs, leaving her with 6,573 shares of common stock held directly. Following the transaction, she also directly held 22,283 RSUs, which continue to represent the right to receive an equal number of common shares upon future vesting.

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

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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^*

Szyman Catherine M.

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/12/2026

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	02/12/2026		M		11,141	A	$132.96	11,141	D
Common Stock	02/12/2026		F		4,568(1)	D	$0	6,573	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
Restricted Stock Units	(2)	02/12/2026		M			11,141	(3)	02/12/2035	Common Stock	11,141	$0	22,283	D

Explanation of Responses:

1. 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.

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

3. 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.

Remarks:

	/s/ Micah W. Young, Attorney-In-Fact	02/13/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transaction did Masimo (MASI) CEO Catherine Szyman report?

Masimo CEO Catherine M. Szyman reported vesting and conversion of 11,141 restricted stock units into common shares, with a portion of those shares withheld to satisfy tax obligations, as shown in her Form 4 filing dated February 12, 2026.

How many Masimo (MASI) restricted stock units vested for the CEO on February 12, 2026?

On February 12, 2026, 11,141 of Catherine Szyman’s restricted stock units vested and were converted into an equal number of Masimo common shares. These RSUs are part of a 33,424-unit grant scheduled to vest ratably over three years from February 12, 2025.

Why were 4,568 Masimo (MASI) shares withheld in the CEO’s Form 4?

The 4,568 Masimo shares were withheld by the company to satisfy tax withholding obligations related to the vesting of performance restricted stock units. This “F” transaction code reflects a tax-withholding disposition, not an open-market sale by CEO Catherine Szyman.

How many Masimo (MASI) shares and RSUs does the CEO hold after this Form 4?

After the reported transactions, CEO Catherine Szyman directly holds 6,573 shares of Masimo common stock and 22,283 restricted stock units. Each RSU represents the contingent right to receive one Masimo common share upon future vesting milestones.

What does transaction code M mean in the Masimo (MASI) CEO’s Form 4?

Transaction code M in the CEO’s Form 4 indicates an exercise or conversion of a derivative security, in this case restricted stock units. Catherine Szyman’s 11,141 RSUs were converted into 11,141 Masimo common shares as part of scheduled vesting.

Are the Masimo (MASI) CEO’s Form 4 transactions open-market buys or sells?

The reported transactions are not open-market buys or sells. They reflect RSU vesting and conversion (code M) and share withholding for taxes (code F). Shares were issued to CEO Catherine Szyman and some were retained by Masimo to cover tax liabilities.