BIOGEN INC. - Director's Dealing 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2010-12-17

Reporting Person: SCHNEIER CRAIG ERIC (EVP, HR, Public Affairs & Comm)

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-12-17	Common Stock	M	19450	$49.31	Acquired	40566.2794	Direct
2010-12-17	Common Stock	S	19450	$68.20	Disposed	21116.2794	Direct

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-12-17	Stock Option (Right to Buy)	$49.31	M	19450	Disposed	2017-02-11	Common Stock (19450)	Direct

Security	Shares	Ownership
Common Stock	460	Indirect

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

F2: Granted under one of the Issuer's stock option plans, in an exempt transaction under SEC rule 16(b)-3(d).

F3: The stock option becomes exercisable in four (4) equal annual installments, commencing one year after the grant date of 02/12/07.