BIOGEN INC. — Director's Dealing 2010

Jan 6, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2010-01-04

Reporting Person: DORSA CAROLINE (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-01-04	Common Stock	A	965	—	Acquired	965	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-01-04	Stock Option (Right to Buy)	$53.64	A	2570	Acquired	2020-01-03	Common Stock (2570)	Direct
2010-01-04	Stock Option (Right to Buy)	$53.64	A	35000	Acquired	2020-01-03	Common Stock (35000)	Direct

Footnotes

F1: Granted under one of the Issuer's stock option plans, in an exempt transaction under SEC Rule 16(b)-3(d).

F2: The stock options become exercisable in three (3) equal annual installments commencing one year after the grant date of 01/04/2010.