MASIMO CORP — Director's Dealing 2018

May 5, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MASIMO CORP (MASI)
CIK: 0000937556
Period of Report: 2018-05-03

Reporting Person: Van Ramshorst David J (Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-03	Common Stock	M	1500	$37.84	Acquired	2500	Direct
2018-05-03	Common Stock	S	1500	$95	Disposed	1000	Direct
2018-05-04	Common Stock	M	3000	$29.90	Acquired	4000	Direct
2018-05-04	Common Stock	S	3000	$97.50	Disposed	1000	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2018-05-03	Non-Qualified Stock Option (Right to Buy)	$37.84	M	1500	Disposed	2026-03-01	Common Stock (1500.0)	Direct
2018-05-04	Non-Qualified Stock Option (Right to Buy)	$29.9	M	3000	Disposed	2025-02-20	Common Stock (3000.0)	Direct

Footnotes

F1: The shares covered by this Form 4 were exercised and sold pursuant to a Rule 10b5-1 Sales Plan dated as of March 14, 2018, which is intended to comply with Rule 10b5-1 promulgated under the Securities Exchange Act of 1934, as amended.

F2: This option was granted on February 29, 2016 and is exercisable as the option vests. The option vests over a five year period, with 20% of the shares subject to the option vesting on each anniversary of the grant date.

F3: This option was granted on February 20, 2015 and is exercisable as the option vests. The option vests over a five year period, with 20% of the shares subject to the option vesting on each anniversary of the grant date.