    <SEC-DOCUMENT>0001437749-21-014666-index.html : 20210614
    <SEC-HEADER>0001437749-21-014666.hdr.sgml : 20210614
    <ACCEPTANCE-DATETIME>20210614081748
    ACCESSION NUMBER:		0001437749-21-014666
    CONFORMED SUBMISSION TYPE:	SC 13D/A
    PUBLIC DOCUMENT COUNT:		27
    FILED AS OF DATE:		20210614
    DATE AS OF CHANGE:		20210614
    GROUP MEMBERS:		MARK J. PENN

    SUBJECT COMPANY:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MDC PARTNERS INC
    		CENTRAL INDEX KEY:			0000876883
    		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ADVERTISING AGENCIES [7311]
    		IRS NUMBER:				980364441
    		STATE OF INCORPORATION:			A6
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		SC 13D/A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	005-53561
    		FILM NUMBER:		211013362

    	BUSINESS ADDRESS:
    		STREET 1:		ONE WORLD TRADE CENTER, FLOOR 65
    		CITY:			NEW YORK
    		STATE:			NY
    		ZIP:			10007
    		BUSINESS PHONE:		646 429 1800

    	MAIL ADDRESS:
    		STREET 1:		ONE WORLD TRADE CENTER, FLOOR 65
    		CITY:			NEW YORK
    		STATE:			NY
    		ZIP:			10007

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MDC CORP INC
    		DATE OF NAME CHANGE:	20001204

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MDC COMMUNICATIONS CORP
    		DATE OF NAME CHANGE:	19961028

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MDC CORPORATION
    		DATE OF NAME CHANGE:	19950419

    FILED BY:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Stagwell Agency Holdings LLC
    		CENTRAL INDEX KEY:			0001771728
    		IRS NUMBER:				833870147
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		SC 13D/A

    	BUSINESS ADDRESS:
    		STREET 1:		1808 I STREENET, NW
    		STREET 2:		6TH FLOOR
    		CITY:			WASHINGTON
    		STATE:			DC
    		ZIP:			20006
    		BUSINESS PHONE:		9177652638

    	MAIL ADDRESS:
    		STREET 1:		1808 I STREENET, NW
    		STREET 2:		6TH FLOOR
    		CITY:			WASHINGTON
    		STATE:			DC
    		ZIP:			20006
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>SC 13D/A
    <SEQUENCE>1
    <FILENAME>sah20210613_sc13da.htm
    <DESCRIPTION>SCHEDULE 13D/A
    <TEXT>
    Document 1 - file: sah20210613_sc13da.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.N
    <SEQUENCE>2
    <FILENAME>ex_257051.htm
    <DESCRIPTION>EXHIBIT 99.N
    <TEXT>
    Document 2 - file: ex_257051.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.O
    <SEQUENCE>3
    <FILENAME>ex_257052.htm
    <DESCRIPTION>EXHIBIT 99.O
    <TEXT>
    Document 3 - file: ex_257052.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.P
    <SEQUENCE>4
    <FILENAME>ex_257053.htm
    <DESCRIPTION>EXHIBIT 99.P
    <TEXT>
    Document 4 - file: ex_257053.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>a01.jpg
    <TEXT>
    Document 5 - file: a01.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>a02.jpg
    <TEXT>
    Document 6 - file: a02.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>a03.jpg
    <TEXT>
    Document 7 - file: a03.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>a04.jpg
    <TEXT>
    Document 8 - file: a04.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>a05.jpg
    <TEXT>
    Document 9 - file: a05.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>a06.jpg
    <TEXT>
    Document 10 - file: a06.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>a07.jpg
    <TEXT>
    Document 11 - file: a07.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>a08.jpg
    <TEXT>
    Document 12 - file: a08.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>a09.jpg
    <TEXT>
    Document 13 - file: a09.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>a10.jpg
    <TEXT>
    Document 14 - file: a10.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>a11.jpg
    <TEXT>
    Document 15 - file: a11.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>a12.jpg
    <TEXT>
    Document 16 - file: a12.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>a13.jpg
    <TEXT>
    Document 17 - file: a13.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>a14.jpg
    <TEXT>
    Document 18 - file: a14.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>a15.jpg
    <TEXT>
    Document 19 - file: a15.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>a16.jpg
    <TEXT>
    Document 20 - file: a16.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>a17.jpg
    <TEXT>
    Document 21 - file: a17.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>a18.jpg
    <TEXT>
    Document 22 - file: a18.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>a19.jpg
    <TEXT>
    Document 23 - file: a19.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>a20.jpg
    <TEXT>
    Document 24 - file: a20.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>logo.jpg
    <TEXT>
    Document 25 - file: logo.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>logoa.jpg
    <TEXT>
    Document 26 - file: logoa.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>27
    <FILENAME>sig.jpg
    <TEXT>
    Document 27 - file: sig.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>