<SEC-DOCUMENT>0001104659-25-031494.txt : 20250403
<SEC-HEADER>0001104659-25-031494.hdr.sgml : 20250403
<ACCEPTANCE-DATETIME>20250403094004
ACCESSION NUMBER:		0001104659-25-031494
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20250401
FILED AS OF DATE:		20250403
DATE AS OF CHANGE:		20250403

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Schremser Christopher L.
		CENTRAL INDEX KEY:			0001998333
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42125
		FILM NUMBER:		25807745

	MAIL ADDRESS:	
		STREET 1:		1550 DIGITAL DRIVE, #300
		CITY:			LEHI
		STATE:			UT
		ZIP:			84043

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Waystar Holding Corp.
		CENTRAL INDEX KEY:			0001990354
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
		ORGANIZATION NAME:           	06 Technology
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1550 DIGITAL DRIVE, #300
		CITY:			LEHI
		STATE:			UT
		ZIP:			84043
		BUSINESS PHONE:		844-492-9782

	MAIL ADDRESS:	
		STREET 1:		1550 DIGITAL DRIVE, #300
		CITY:			LEHI
		STATE:			UT
		ZIP:			84043
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
<FILENAME>tm2511308-6_4seq1.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-04-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001990354</issuerCik>
        <issuerName>Waystar Holding Corp.</issuerName>
        <issuerTradingSymbol>WAY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001998333</rptOwnerCik>
            <rptOwnerName>Schremser Christopher L.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1550 DIGITAL DRIVE, #300</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LEHI</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Technology Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-04-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>264131</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>438044</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Reflects a grant of restricted stock units (&quot;RSUs&quot;) which vest over 4 years, with 40% vesting in year 3 and 60% vesting in year 4. Each RSU represents a contingent right to receive one share of common stock, $0.01 par value per share (the &quot;Common Stock&quot;) upon settlement.</footnote>
        <footnote id="F2">Includes unvested RSUs.</footnote>
    </footnotes>

    <remarks>Exhibit List: Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Gregory R. Packer, as Attorney-in-Fact</signatureName>
        <signatureDate>2025-04-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>tm2511308d6_ex24.htm
<DESCRIPTION>EXHIBIT 24
<TEXT>
<HTML>
<HEAD>
     <TITLE></TITLE>
</HEAD>
<BODY STYLE="font: 10pt Times New Roman, Times, Serif">

<P STYLE="text-align: right; margin: 0"><B>Exhibit 24</B></P>

<P STYLE="margin: 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Power of Attorney</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Know all by these presents that the undersigned, does hereby make,
constitute and appoint each of GREGORY R. PACKER and STEVEN M. ORESKOVICH, or any one of them, as a true and lawful attorney-in-fact of
the undersigned with full powers of substitution and revocation, for and in the name, place and stead of the undersigned (in the undersigned&rsquo;s
individual capacity), to execute and deliver such forms that the undersigned may be required to file with the U.S. Securities and Exchange
Commission as a result of the undersigned&rsquo;s ownership of or transactions in securities of WAYSTAR HOLDING CORP. (i)&nbsp;pursuant
to Section&nbsp;16(a)&nbsp;of the Securities Exchange Act of 1934, as amended, including without limitation, statements on Form&nbsp;3,
Form&nbsp;4 and Form&nbsp;5 (including any amendments thereto) and (ii)&nbsp;in connection with any applications for EDGAR access codes,
including without limitation the Form&nbsp;ID. The Power of Attorney shall remain in full force and effect until the undersigned is no
longer required to file Forms 3, 4 and 5 with regard to his or her ownership of or transactions in securities of WAYSTAR HOLDING CORP.,
unless earlier revoked in writing. The undersigned acknowledges that GREGORY R. PACKER and STEVEN M. ORESKOVICH are not assuming any of
the undersigned&rsquo;s responsibilities to comply with Section&nbsp;16 of the Securities Exchange Act of 1934, as amended.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; font: 10pt Times New Roman, Times, Serif; border-collapse: collapse">
  <TR STYLE="vertical-align: top">
    <TD STYLE="width: 50%; text-align: right">&nbsp;</TD>
    <TD STYLE="padding-right: 5pt; width: 5%; text-align: right">By:</TD>
    <TD STYLE="border-bottom: Black 1pt solid; width: 45%">/s/ Christopher L. Schremser</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD STYLE="text-align: right">&nbsp;</TD>
    <TD STYLE="padding-right: 5pt; text-align: right">Name:</TD>
    <TD>Christopher L. Schremser</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD STYLE="text-align: right">&nbsp;</TD>
    <TD STYLE="padding-right: 5pt; text-align: right">&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD>Date: March&nbsp;24, 2025</TD>
    <TD STYLE="padding-right: 5pt">&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
  </TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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</SEC-DOCUMENT>
