BIOGEN INC. — Director's Dealing 2018

Feb 14, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2018-02-12

Reporting Person: Sandrock Alfred (EVP, Chief Medical Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-02-12	Common Stock	F	598	$316.63	Disposed	6553.3821	Direct
2018-02-12	Common Stock	M	2012	—	Acquired	8565.3821	Direct
2018-02-12	Common Stock	F	718	$316.63	Disposed	7847.3821	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2018-02-12	Restricted Stock Unit	$0	A	3315	Acquired	2020-02-12	Common Stock (3315)	Direct
2018-02-12	Restricted Stock Unit	$0	A	8290	Acquired	2021-02-12	Common Stock (8290)	Direct
2018-02-12	Restricted Stock Unit	$0	M	2012	Disposed	2019-02-12	Common Stock (2012)	Direct
2018-02-12	Restricted Stock Unit	$0	J	1398	Disposed	2019-02-12	Common Stock (1398)	Direct

Footnotes

F1: Includes 91.527 shares acquired under the Biogen Inc. Employee Stock Purchase Plan on 3/31/2017.

F2: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

F3: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price following and including the grant date]).

F4: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-fourth of these RSUs are eligible to vest each year for four years, beginning two years from the date of grant. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen Idec common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).