<SEC-DOCUMENT>0000080255-15-000348-index.html : 20150212
<SEC-HEADER>0000080255-15-000348.hdr.sgml : 20150212
<ACCEPTANCE-DATETIME>20150212143008
ACCESSION NUMBER:		0000080255-15-000348
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20150212
DATE AS OF CHANGE:		20150212

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BIOGEN IDEC INC.
		CENTRAL INDEX KEY:			0000875045
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				330112644
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-42028
		FILM NUMBER:		15605125

	BUSINESS ADDRESS:	
		STREET 1:		225 BINNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142
		BUSINESS PHONE:		7814642000

	MAIL ADDRESS:	
		STREET 1:		225 BINNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BIOGEN IDEC INC
		DATE OF NAME CHANGE:	20031112

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IDEC PHARMACEUTICALS CORP / DE
		DATE OF NAME CHANGE:	19970530

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRICE T ROWE ASSOCIATES INC /MD/
		CENTRAL INDEX KEY:			0000080255
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY & COMMODITY BROKERS, DEALERS, EXCHANGES & SERVICES [6200]
		IRS NUMBER:				520556948
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		100 EAST PRATT ST
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202
		BUSINESS PHONE:		(410)345-6603

	MAIL ADDRESS:	
		STREET 1:		P.O. BOX 89000
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21289
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>biib13gdec14.htm
<DESCRIPTION>BIIB AS OF 12/31/2014
<TEXT>
Document 1 - file: biib13gdec14.htm

</DOCUMENT>
</SEC-DOCUMENT>