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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001476328-10-000002.txt : 20100223
<SEC-HEADER>0001476328-10-000002.hdr.sgml : 20100223
<ACCEPTANCE-DATETIME>20100223120932
ACCESSION NUMBER:		0001476328-10-000002
CONFORMED SUBMISSION TYPE:	D
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
ITEM INFORMATION:		Investment Company Act Section 3(c)
ITEM INFORMATION:		Section 3(c)(7)
FILED AS OF DATE:		20100223
DATE AS OF CHANGE:		20100223
EFFECTIVENESS DATE:		20100223

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			R3 (B), L.P.
		CENTRAL INDEX KEY:			0001484759
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		D
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-138964
		FILM NUMBER:		10624935

	BUSINESS ADDRESS:	
		STREET 1:		C/O BLACKROCK, INC.
		STREET 2:		PARK AVENUE PLAZA, 55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-810-5300

	MAIL ADDRESS:	
		STREET 1:		C/O BLACKROCK, INC.
		STREET 2:		PARK AVENUE PLAZA, 55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>D
<SEQUENCE>1
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        <cik>0001484759</cik>
        <entityName>R3 (B), L.P.</entityName>
        <issuerAddress>
            <street1>C/O BLACKROCK, INC.</street1>
            <street2>PARK AVENUE PLAZA, 55 EAST 52ND STREET</street2>
            <city>NEW YORK</city>
            <stateOrCountry>NY</stateOrCountry>
            <zipCode>10022</zipCode>
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        <issuerPhoneNumber>212-810-5300</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
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        <entityType>Limited Partnership</entityType>
        <yearOfInc>
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            <value>2009</value>
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    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>n/a</firstName>
                <lastName>BlackRock RRR (GenPar), LLC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Park Avenue Plaza, 55 East 52nd Street</street1>
                <city>New York</city>
                <stateOrCountry>NY</stateOrCountry>
                <zipCode>10022</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>n/a</firstName>
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                <street1>Park Avenue Plaza, 55 East 52nd Street</street1>
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                <zipCode>10022</zipCode>
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                <zipCode>10022</zipCode>
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                <zipCode>10022</zipCode>
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                <street1>BlackRock, Inc.</street1>
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                <city>New York</city>
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                <zipCode>10022</zipCode>
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            <relatedPersonRelationshipList>
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                <firstName>Michael</firstName>
                <lastName>Lipsky</lastName>
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                <street1>BlackRock, Inc.</street1>
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                <zipCode>10022</zipCode>
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            <relatedPersonRelationshipList>
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                <street1>BlackRock, Inc.</street1>
                <street2>Park Avenue Plaza, 55 East 52nd Street</street2>
                <city>New York</city>
                <stateOrCountry>NY</stateOrCountry>
                <zipCode>10022</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
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            <relationshipClarification></relationshipClarification>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Richard</firstName>
                <middleName>M</middleName>
                <lastName>Rieder</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>BlackRock, Inc.</street1>
                <street2>Park Avenue Plaza, 55 East 52nd Street</street2>
                <city>New York</city>
                <stateOrCountry>NY</stateOrCountry>
                <zipCode>10022</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
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            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Neeraj</firstName>
                <lastName>Seth</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>BlackRock, Inc.</street1>
                <street2>Park Avenue Plaza, 55 East 52nd Street</street2>
                <city>New York</city>
                <stateOrCountry>NY</stateOrCountry>
                <zipCode>10022</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
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            <relationshipClarification></relationshipClarification>
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            <relatedPersonName>
                <firstName>John</firstName>
                <lastName>Stein</lastName>
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            <relatedPersonAddress>
                <street1>BlackRock, Inc.</street1>
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            <relatedPersonRelationshipList>
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        <relatedPersonInfo>
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                <lastName>Tarnow</lastName>
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            <relatedPersonAddress>
                <street1>BlackRock, Inc.</street1>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Paul</firstName>
                <middleName>H</middleName>
                <lastName>Tice</lastName>
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        <relatedPersonInfo>
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                <firstName>C</firstName>
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    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Hedge Fund</investmentFundType>
                <is40Act>false</is40Act>
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        </industryGroup>
        <issuerSize>
            <aggregateNetAssetValueRange>Decline to Disclose</aggregateNetAssetValueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
            <item>3C</item>
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        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>false</isAmendment>
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            <dateOfFirstSale>
                <value>2009-10-01</value>
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        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
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        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
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        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
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        <minimumInvestmentAccepted>100000</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>2067174</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
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        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>6</totalNumberAlreadyInvested>
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        <salesCommissionsFindersFees>
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                <issuerName>R3 (B), L.P.</issuerName>
                <signatureName>C. Michael Weaver</signatureName>
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-----END PRIVACY-ENHANCED MESSAGE-----