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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-06-22</periodOfReport>

    <issuer>
        <issuerCik>0001258602</issuerCik>
        <issuerName>NELNET INC</issuerName>
        <issuerTradingSymbol>NNI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001417993</rptOwnerCik>
            <rptOwnerName>Rath Kimberly Kay</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>121 SOUTH 13TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>LINCOLN</rptOwnerCity>
            <rptOwnerState>NE</rptOwnerState>
            <rptOwnerZipCode>68508</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-06-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2334</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>51.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2334</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>42603</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1-for-1.</footnote>
        <footnote id="F2">The shares of phantom stock were granted pursuant to the issuer's Directors Stock Compensation Plan.  They will become payable in shares of Class A Common Stock at the time of termination of the reporting person's service as a member of the issuer's Board of Directors.  The shares will be payable in a lump sum at the time of termination of the reporting person's service as a member of the issuer's Board, or in up to five annual installments, commencing at the time of termination of the reporting person's service on the issuer's Board, as elected by the reporting person.</footnote>
        <footnote id="F3">Includes 461 shares acquired since June 27, 2017 pursuant to the dividend reinvestment feature of the issuer's Directors Stock Compensation Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Audra Hoffschneider, Attorney-in-Fact for Kimberly Kay Rath</signatureName>
        <signatureDate>2018-06-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
