BIOGEN INC. - Director's Dealing 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2012-06-15

Reporting Person: ALEXANDER SUSAN H (EVP, General Counsel)

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-06-15	Common Stock	M	20000	$45.72	Acquired	30185	Direct
2012-06-15	Common Stock	M	29800	$49.31	Acquired	59985	Direct
2012-06-15	Common Stock	S	49800	$140.00	Disposed	10185	Direct

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-06-15	Stock Option (Right to Buy)	$45.72	M	20000	Disposed	2016-02-15	Common Stock (20000)	Direct
2012-06-15	Stock Option (Right to Buy)	$49.31	M	29800	Disposed	2017-02-12	Common Stock (29800)	Direct

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 02/15/06.

F4: The stock option becomes exercisable in four (4) equal annual installments, commencing one year after the grant date of 02/12/07.