MASIMO CORP — Director's Dealing 2010

May 17, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MASIMO CORP (MASI)
CIK: 0000937556
Period of Report: 2010-05-17

Reporting Person: Allan Anthony (Chief Operating Officer)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-05-17	Non-qualified stock option (right to buy)	$23.97	A	150000	Acquired	2020-05-17	Common Stock (150000)	Direct

Footnotes

F1: This option was granted on May 17, 2010 and is exercisable as the option vests. This option vests over a five-year period, with 20% of the shares subject to the option vesting on each anniversary of the grant date.