<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
    <periodOfReport>2003-08-22</periodOfReport>
    <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000811156</issuerCik>
        <issuerName>CMS ENERGY CORP</issuerName>
        <issuerTradingSymbol>CMS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001180661</rptOwnerCik>
            <rptOwnerName>RUSSELL JOHN G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>EVP-Sub, Consumers Energy</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
  <nonDerivativeTable>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>Common Stock (CMS)</value>
      </securityTitle>
      <transactionDate>
          <value>2003-08-22</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>A</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>20000</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>6.35</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>34621</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>Common Stock (CMS)</value>
      </securityTitle>
      <transactionDate>
          <value>2003-08-22</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>J</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
              <footnoteId id="F2" />
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>2000</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>0</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>D</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>32621</value>
              <footnoteId id="F3" />
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
    <nonDerivativeHolding>
      <securityTitle>
          <value>Common Stock (CMS)</value>
      </securityTitle>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>2972</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>I</value>
          </directOrIndirectOwnership>
          <natureOfOwnership>
              <value>401(k)</value>
          </natureOfOwnership>
      </ownershipNature>
   </nonDerivativeHolding>
  </nonDerivativeTable>
  <derivativeTable>
   <derivativeTransaction>
      <securityTitle>
          <value>Emp Stock Options-2003</value>
      </securityTitle>
      <conversionOrExercisePrice>
          <value>6</value>
      </conversionOrExercisePrice>
      <transactionDate>
          <value>2003-08-22</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>A</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
          <transactionShares>
              <value>76000</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>6.35</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
          <value>2003-08-22</value>
      </exerciseDate>
      <expirationDate>
          <value>2013-09-21</value>
      </expirationDate>
      <underlyingSecurity>
          <underlyingSecurityTitle>
              <value>Common Stock (CMS)</value>
          </underlyingSecurityTitle>
          <underlyingSecurityShares>
              <value>76000</value>
          </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>76000</value>
              <footnoteId id="F4" />
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
  </derivativeTable>
<footnotes>
   <footnote id="F2">Forfeiture of Restricted Stock granted in 2000 pursuant to provisions of CMS Performance Incentive Stock Plan.</footnote>
   <footnote id="F3">Total includes 32,000 shares of Restricted Stock of CMS, of which 3,000 shares are nominal. (The actual number of nominal shares received will be determined by the passage of time and achievement of performance objectives under CMS' Performance Incentive Stock Plan.). </footnote>
   <footnote id="F4">In addition, previous options were granted on various dates at various prices for 52,000 shares of Common Stock, totalling 128,000 options held directly; and 122 units considered phantom stock are held indirectly pursuant to the Deferred Salary Savings Plan of CMS.</footnote>
</footnotes>
    <ownerSignature>
       <signatureName>/s/MDVanHemert, Attny in Fact</signatureName>
       <signatureDate>2003-08-26</signatureDate>
    </ownerSignature>
</ownershipDocument>

