BIOGEN INC. — Director's Dealing 2011

Jan 4, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2010-12-31

Reporting Person: YOUNG WILLIAM (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-12-31	Common Stock	M	15000	$59.25	Acquired	34315	Direct
2010-12-31	Common Stock	F	13256	$67.05	Disposed	21059	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-12-31	Stock Option (Right to Buy)	$59.25	M	15000	Disposed	2011-01-01	Common Stock (15000)	Direct