EVRG: amended insider filing

<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2026-06-15</periodOfReport>

    <dateOfOriginalSubmission>2026-06-16</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0001711269</issuerCik>
        <issuerName>Evergy, Inc.</issuerName>
        <issuerTradingSymbol>EVRG</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001514004</rptOwnerCik>
            <rptOwnerName>Caisley Charles A.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O EVERGY, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1200 MAIN STREET</rptOwnerStreet2>
            <rptOwnerCity>KANSAS CITY</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>64105</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>EVP &amp; CHIEF CUST OFFCR</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1198</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>83.46</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36591</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On June 16, 2026, the reporting person filed a Form 4 which inadvertently omitted the sale of 1,198 shares of common stock.  In total, the reporting person sold 11,985 shares of common stock.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $83.45 to $83.50, inclusive. The reporting person undertakes to provide to Evergy, Inc., any security holder of Evergy, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range indicated in this footnote.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Executed on behalf of Charles A. Caisley by Amy Abrams, attorney-in-fact</signatureName>
        <signatureDate>2026-10-09</signatureDate>
    </ownerSignature>
</ownershipDocument>