    <SEC-DOCUMENT>0000937556-19-000076-index.html : 20190412
    <SEC-HEADER>0000937556-19-000076.hdr.sgml : 20190412
    <ACCEPTANCE-DATETIME>20190412163225
    ACCESSION NUMBER:		0000937556-19-000076
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		59
    CONFORMED PERIOD OF REPORT:	20181229
    FILED AS OF DATE:		20190412
    DATE AS OF CHANGE:		20190412
    EFFECTIVENESS DATE:		20190412

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MASIMO CORP
    		CENTRAL INDEX KEY:			0000937556
    		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS [3845]
    		IRS NUMBER:				330368882
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1229

    	FILING VALUES:
    		FORM TYPE:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-33642
    		FILM NUMBER:		19746645

    	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
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    <FILENAME>masi-20190412xdef14a.htm
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    Document 1 - file: masi-20190412xdef14a.htm

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    <FILENAME>a5yeartotalreturnchart.jpg
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    Document 2 - file: a5yeartotalreturnchart.jpg

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    <FILENAME>adjustedproductrevenue2.jpg
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    Document 3 - file: adjustedproductrevenue2.jpg

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    Document 4 - file: adjustedproductrevenue.jpg

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    Document 5 - file: annualincentivepiea02.jpg

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    Document 6 - file: annualmtginfoa03.jpg

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    Document 7 - file: asampath.jpg

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    Document 8 - file: barcodex2a03.jpg

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    Document 9 - file: barcodex5a03.jpg

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    Document 10 - file: basesalarypie.jpg

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    Document 11 - file: bmuhsin.jpg

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    Document 12 - file: boardindependence.jpg

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    <FILENAME>boardqualifications.jpg
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    Document 13 - file: boardqualifications.jpg

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    Document 14 - file: boardtenure.jpg

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    Document 15 - file: calculatora03.jpg

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    Document 16 - file: cashflowa1.jpg

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    <FILENAME>cellphone.jpg
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    Document 17 - file: cellphone.jpg

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    <FILENAME>ceorisk2.jpg
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    Document 18 - file: ceorisk2.jpg

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    Document 19 - file: ceorisk3.jpg

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    <FILENAME>ceorisk.jpg
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    Document 20 - file: ceorisk.jpg

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    <FILENAME>earnings2.jpg
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    Document 21 - file: earnings2.jpg

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    <FILENAME>equitypiea1.jpg
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    Document 22 - file: equitypiea1.jpg

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    <FILENAME>genderdiversity.jpg
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    Document 23 - file: genderdiversity.jpg

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    <FILENAME>globalreach2.jpg
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    Document 24 - file: globalreach2.jpg

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    <FILENAME>jcoleman.jpg
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    Document 25 - file: jcoleman.jpg

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    <FILENAME>jkiani.jpg
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    Document 26 - file: jkiani.jpg

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    Document 27 - file: jksignature2019.jpg

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    <FILENAME>laptop.jpg
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    Document 28 - file: laptop.jpg

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    <FILENAME>legend.jpg
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    Document 29 - file: legend.jpg

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    <FILENAME>location.jpg
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    Document 30 - file: location.jpg

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    <FILENAME>mailbox.jpg
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    Document 31 - file: mailbox.jpg

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    Document 32 - file: masimo2019proxycover.jpg

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    <FILENAME>masimologo300x1a03.jpg
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    Document 33 - file: masimologo300x1a03.jpg

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    <FILENAME>masimologo2019.jpg
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    Document 34 - file: masimologo2019.jpg

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    Document 35 - file: masimologoblkwhtx3a03.jpg

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    Document 36 - file: masimologoq22016eaa14.jpg

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    <SEQUENCE>37
    <FILENAME>myoung.jpg
    <TEXT>
    Document 37 - file: myoung.jpg

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    <SEQUENCE>38
    <FILENAME>neorisk2.jpg
    <TEXT>
    Document 38 - file: neorisk2.jpg

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    <SEQUENCE>39
    <FILENAME>neorisk3.jpg
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    Document 39 - file: neorisk3.jpg

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    <SEQUENCE>40
    <FILENAME>neorisk.jpg
    <TEXT>
    Document 40 - file: neorisk.jpg

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    <SEQUENCE>41
    <FILENAME>nongaapeps2.jpg
    <TEXT>
    Document 41 - file: nongaapeps2.jpg

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    <SEQUENCE>42
    <FILENAME>nongaapeps.jpg
    <TEXT>
    Document 42 - file: nongaapeps.jpg

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    <SEQUENCE>43
    <FILENAME>profitmargin.jpg
    <TEXT>
    Document 43 - file: profitmargin.jpg

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    Document 44 - file: proxycardx1a03.jpg

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    Document 45 - file: qrcodeblk.jpg

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    Document 46 - file: qrcodemasimox2a03.jpg

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    <FILENAME>rearcover2019.jpg
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    Document 47 - file: rearcover2019.jpg

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    <SEQUENCE>48
    <FILENAME>recorddate2.jpg
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    Document 48 - file: recorddate2.jpg

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    <SEQUENCE>49
    <FILENAME>reduparrow.jpg
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    Document 49 - file: reduparrow.jpg

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    <SEQUENCE>50
    <FILENAME>revenue.jpg
    <TEXT>
    Document 50 - file: revenue.jpg

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    <SEQUENCE>51
    <FILENAME>setlnscsensora01.jpg
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    Document 51 - file: setlnscsensora01.jpg

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    <SEQUENCE>52
    <FILENAME>shareholderletterjk.jpg
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    Document 52 - file: shareholderletterjk.jpg

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    <FILENAME>shipments.jpg
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    Document 53 - file: shipments.jpg

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    Document 54 - file: spiralcalendarpad1f5d3.jpg

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    <FILENAME>tlevy.jpg
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    Document 55 - file: tlevy.jpg

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    <FILENAME>tmcclenahan.jpg
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    Document 56 - file: tmcclenahan.jpg

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    Document 57 - file: toplogowhtx1a03.jpg

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    <FILENAME>toplogowhtx1a05.jpg
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    Document 58 - file: toplogowhtx1a05.jpg

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    <FILENAME>ylee.jpg
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    Document 59 - file: ylee.jpg

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