BIOGEN INC. — Director's Dealing 2013

Feb 7, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2013-02-06

Reporting Person: PANGIA ROBERT W (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-02-06	Common Stock	M	2500	$66.29	Acquired	21098	Direct
2013-02-06	Common Stock	S	2500	$165.55	Disposed	18598	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-02-06	Stock Option (Right to Buy)	$66.29	M	2500	Disposed	2015-01-03	Common Stock (2500)	Direct

Footnotes

F1: Exercise/sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

F2: Granted under one of the Issuer's stock option plans, in an exempt transaction under SEC rule 16(b)-3(d).

F3: Immediately exercisable for all the option shares on grant date of 01/03/2005 subject to Issuer's repurchase rights which lapse on 01/03/2006.