BIOGEN INC. — Director's Dealing 2011

Apr 25, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2011-04-21

Reporting Person: Cox John (EVP Pharmaceutical Oper & Tech)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-04-21	Common Stock	M	4350	$72.87	Acquired	14703.0295	Direct
2011-04-21	Common Stock	S	4350	$100.00	Disposed	10353.0295	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-04-21	Stock Option (Right to Buy)	$72.87	M	4350	Disposed	2017-11-01	Common Stock (4350)	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: The stock options vest in four (4) equal annual installments commencing one year after the grant date of 11/1/2007.