<SEC-DOCUMENT>0001181431-11-034756.txt : 20110603
<SEC-HEADER>0001181431-11-034756.hdr.sgml : 20110603
<ACCEPTANCE-DATETIME>20110603162859
ACCESSION NUMBER:		0001181431-11-034756
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110601
FILED AS OF DATE:		20110603
DATE AS OF CHANGE:		20110603

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MILLER FREDERICK V MD
		CENTRAL INDEX KEY:			0001443060

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12111
		FILM NUMBER:		11892574

	MAIL ADDRESS:	
		STREET 1:		1301 CONCORD TERRACE
		CITY:			SUNRISE
		STATE:			FL
		ZIP:			33323

	FORMER NAME:	
		FORMER CONFORMED NAME:	MILLER FREDERICK V
		DATE OF NAME CHANGE:	20080814

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MEDNAX, INC.
		CENTRAL INDEX KEY:			0000893949
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-HOSPITALS [8060]
		IRS NUMBER:				650271219
		STATE OF INCORPORATION:			FL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1301 CONCORD TERRACE
		CITY:			SUNRISE
		STATE:			FL
		ZIP:			33323
		BUSINESS PHONE:		9543840175

	MAIL ADDRESS:	
		STREET 1:		1301 CONCORD TERRACE
		CITY:			SUNRISE
		STATE:			FL
		ZIP:			33323

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PEDIATRIX MEDICAL GROUP INC
		DATE OF NAME CHANGE:	19950801
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd313994.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-06-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000893949</issuerCik>
        <issuerName>MEDNAX, INC.</issuerName>
        <issuerTradingSymbol>MD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001443060</rptOwnerCik>
            <rptOwnerName>MILLER FREDERICK V MD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1301 CONCORD TERRACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SUNRISE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33323-2825</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Pediatrix Division</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9268</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30949</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5833</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>55.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36782</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5833</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>73.6144</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30949</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Options (Right to Buy)</value>
                <footnoteId id="F4"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>55.43</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2011-06-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5833</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>55.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2011-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5833</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted shares granted pursuant to the Issuer's 2008 Incentive Compensation Plan in connection with annual equity award.  The vesting of the restricted shares is subject to performance based criteria but will not vest any earlier than in three equal installments on June 1, 2012, June 1, 2013 and June 1, 2014.</footnote>
        <footnote id="F2">Sales of shares were made pursuant to the Reporting Person's 10b5-1 trading plan.</footnote>
        <footnote id="F3">Sales of shares were executed in fifty-three (53) separate transactions with prices ranging from $72.72 to $74.66 for a weighted average sales price of $73.6144.</footnote>
        <footnote id="F4">Stock Options granted pursuant to Issuer's 2008 Incentive Compensation Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Thomas W. Hawkins Attorney-in-fact</signatureName>
        <signatureDate>2011-06-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
