BIOGEN INC. — Director's Dealing 2010

Mar 23, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2010-03-19

Reporting Person: MacLean Michael F (SVP, Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-03-19	Common Stock	S	4085	$60.00	Disposed	20313.9467	Direct

Footnotes

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