<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001998256</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001990354</issuerCik>
            <issuerName>WAYSTAR HOLDING CORP</issuerName>
            <secFileNumber>001-42125</secFileNumber>
            <issuerAddress>
                <ns2:street1>1550 Digital Drive, #300</ns2:street1>
                <ns2:city>Lehi</ns2:city>
                <ns2:stateOrCountry>UT</ns2:stateOrCountry>
                <ns2:zipCode>84043</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>8444929782</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MATTHEW J HAWKINS</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</relationshipToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>139999</noOfUnitsSold>
            <aggregateMarketValue>5739959.00</aggregateMarketValue>
            <noOfUnitsOutstanding>172151839</noOfUnitsOutstanding>
            <approxSaleDate>02/21/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/21/2025</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>139999</amountOfSecuritiesAcquired>
            <paymentDate>02/21/2025</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <remarks>The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.&#13;
</remarks>
        <noticeSignature>
            <noticeDate>02/21/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>11/22/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Matthew J. Hawkins</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
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144
0001998256
XXXXXXXX
LIVE
0001990354
WAYSTAR HOLDING CORP
001-42125
1550 Digital Drive, #300
Lehi
UT
84043
8444929782
MATTHEW J HAWKINS
Director
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
139999
5739959.00
172151839
02/21/2025
NASDAQ
Common
02/21/2025
Exercise of Stock Options
Issuer
N
139999
02/21/2025
Cash
Y
The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.
02/21/2025
11/22/2024
/s/ Matthew J. Hawkins