<SEC-DOCUMENT>0001080997-18-000001.txt : 20180810
<SEC-HEADER>0001080997-18-000001.hdr.sgml : 20180810
<ACCEPTANCE-DATETIME>20180810200054
ACCESSION NUMBER:		0001080997-18-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180809
FILED AS OF DATE:		20180810
DATE AS OF CHANGE:		20180810

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MILLS THOMAS E IV
		CENTRAL INDEX KEY:			0001080997

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34460
		FILM NUMBER:		181010071

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KRATOS DEFENSE & SECURITY SOLUTIONS, INC.
		CENTRAL INDEX KEY:			0001069258
		STANDARD INDUSTRIAL CLASSIFICATION:	GUIDED MISSILES & SPACE VEHICLES & PARTS [3760]
		IRS NUMBER:				133818604
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1225

	BUSINESS ADDRESS:	
		STREET 1:		4820 EASTGATE MALL
		STREET 2:		SUITE 200
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		858-812-7300

	MAIL ADDRESS:	
		STREET 1:		4820 EASTGATE MALL
		STREET 2:		SUITE 200
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WIRELESS FACILITIES INC
		DATE OF NAME CHANGE:	19990817
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-08-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001069258</issuerCik>
        <issuerName>KRATOS DEFENSE &amp; SECURITY SOLUTIONS, INC.</issuerName>
        <issuerTradingSymbol>KTOS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001080997</rptOwnerCik>
            <rptOwnerName>MILLS THOMAS E IV</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4820 EASTGATE MALL</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, MS Division</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-08-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>73372</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.1914</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15768</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Open market sale of Issuer's common stock made in accordance with Issuer's trading policies.</footnote>
        <footnote id="F2">Includes approximately 9,518 shares held in Issuer's 401(k) Plan.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $13.0507 to $13.37 inclusive.  The Reporting Person undertakes to provide to Issuer, any security holder of Issuer, 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 ranges set forth in this footnote to this Form 4.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Thomas E. Mills, by Eva Yee, Attorney-In-Fact</signatureName>
        <signatureDate>2018-08-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
