BIOGEN INC. — Director's Dealing 2011

Oct 7, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2011-10-05

Reporting Person: Gagnon Robert E. (Chief Acct Officer VP & Contr)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-10-05	Common Stock	S	252	$97.6595	Disposed	7383	Direct

Footnotes

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

F2: Full information regarding the number of shares sold at each separate price will be provided upon request by the SEC staff, the issuer, or a security holder of the issuer.

F3: This represents the weighted average price for shares sold at a range between $97.5901 (low) and $97.765 (high).