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        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001998332</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>CRAIG BRIDGE</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <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>85000</noOfUnitsSold>
            <aggregateMarketValue>3119500.00</aggregateMarketValue>
            <noOfUnitsOutstanding>173018999</noOfUnitsOutstanding>
            <approxSaleDate>07/21/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>07/19/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Previously Exercised Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>85000</amountOfSecuritiesAcquired>
            <paymentDate>07/19/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for CRAIG BRIDGE</name>
                <address>
                    <ns2:street1>1550 Digital Drive, #300</ns2:street1>
                    <ns2:city>Lehi</ns2:city>
                    <ns2:stateOrCountry>UT</ns2:stateOrCountry>
                    <ns2:zipCode>84043</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>06/11/2025</saleDate>
            <amountOfSecuritiesSold>15946</amountOfSecuritiesSold>
            <grossProceeds>649177.61</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>07/21/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>11/27/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Craig Bridge</signature>
        </noticeSignature>
    </formData>
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144
0001998332
XXXXXXXX
LIVE
0001990354
WAYSTAR HOLDING CORP
001-42125
1550 Digital Drive, #300
Lehi
UT
84043
8444929782
CRAIG BRIDGE
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
85000
3119500.00
173018999
07/21/2025
NASDAQ
Common
07/19/2024
Previously Exercised Options
Issuer
N
85000
07/19/2024
Cash
N
10b5-1 Sales for CRAIG BRIDGE
1550 Digital Drive, #300
Lehi
UT
84043
Common
06/11/2025
15946
649177.61
07/21/2025
11/27/2024
/s/ Craig Bridge