BIOGEN INC. — Director's Dealing 2010

May 3, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2010-04-30

Reporting Person: DORSA CAROLINE (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-04-30	Common Stock	P	187	$53.3785	Acquired	1152	Direct

Footnotes

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