BIOGEN INC. — Director's Dealing 2011

Feb 18, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2011-02-17

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-02-17	Common Stock	S	1843	$67.0752	Disposed	13603.0411	Direct

Footnotes

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

F2: This represents the weighted average price for shares sold at a range between $66.97 (low) and 67.23 (high).

F3: 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.