BIOGEN INC. — Director's Dealing 2011

Sep 2, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2011-09-01

Reporting Person: YOUNG WILLIAM (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-09-01	Common Stock	M	10000	$34.34	Acquired	36859	Direct
2011-09-01	Common Stock	M	12500	$36.94	Acquired	49359	Direct
2011-09-01	Common Stock	M	12500	$66.29	Acquired	61859	Direct
2011-09-01	Common Stock	S	35000	$95.00	Disposed	26859	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-09-01	Stock Option (Right to Buy)	$34.34	M	10000	Disposed	2013-01-01	Common Stock (10000)	Direct
2011-09-01	Non-qualified Stock Option (Right to Buy)	$36.94	M	12500	Disposed	2014-01-01	Common Stock (12500)	Direct
2011-09-01	Stock Option (Right to Buy)	$66.29	M	12500	Disposed	2015-01-03	Common Stock (12500)	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 Issuer's 1993 Non-Employee Director's Stock Option Plan in a transaction exempt under 16(b)3(d).

F3: Immediately exercisable for all the option shares on 1/2/2004 subject to Issuer's repurchase rights which lapse on 1/2/2005.

F4: Granted under one of the Issuer's stock option plans, in an exempt transaction under SEC rule 16(b)-3(d).

F5: 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.