    <SEC-DOCUMENT>0001213900-24-079139-index.html : 20240917
    <SEC-HEADER>0001213900-24-079139.hdr.sgml : 20240917
    <ACCEPTANCE-DATETIME>20240917060603
    ACCESSION NUMBER:		0001213900-24-079139
    CONFORMED SUBMISSION TYPE:	DEFA14A
    PUBLIC DOCUMENT COUNT:		15
    FILED AS OF DATE:		20240917
    DATE AS OF CHANGE:		20240917

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MASIMO CORP
    		CENTRAL INDEX KEY:			0000937556
    		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS [3845]
    		ORGANIZATION NAME:           	08 Industrial Applications and Services
    		IRS NUMBER:				330368882
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1228

    	FILING VALUES:
    		FORM TYPE:		DEFA14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-33642
    		FILM NUMBER:		241302453

    	BUSINESS ADDRESS:
    		STREET 1:		52 DISCOVERY
    		CITY:			IRVINE
    		STATE:			CA
    		ZIP:			92618
    		BUSINESS PHONE:		949-297-7000

    	MAIL ADDRESS:
    		STREET 1:		52 DISCOVERY
    		CITY:			IRVINE
    		STATE:			CA
    		ZIP:			92618
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEFA14A
    <SEQUENCE>1
    <FILENAME>ea0214778-defa14a_masimo.htm
    <DESCRIPTION>DEFINITIVE ADDITIONAL MATERIALS
    <TEXT>
    Document 1 - file: ea0214778-defa14a_masimo.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>image_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: image_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>image_002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: image_002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>image_003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: image_003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>image_004.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: image_004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>image_005.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: image_005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>letter1_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: letter1_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>letter1_002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: letter1_002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>letter2_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: letter2_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>letter3_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: letter3_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>letter3_002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: letter3_002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>letter4_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: letter4_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>letter5_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: letter5_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>letter5_002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: letter5_002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>letter5_003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: letter5_003.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>