BIOGEN INC. — Director's Dealing 2019

Feb 26, 2019

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2019-02-22

Reporting Person: ALEXANDER SUSAN H (EVP Chief Legal Officer & Sec.)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2019-02-22	Common Stock	M	1663	—	Acquired	29690	Direct
2019-02-22	Common Stock	M	6395	$48.52	Acquired	36085	Direct
2019-02-22	Common Stock	F	3370	$325.33	Disposed	32715	Direct
2019-02-22	Common Stock	F	739	$325.33	Disposed	31976	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2019-02-22	Restricted Stock Unit	$0	M	1663	Disposed	2019-02-22	Common Stock (1663)	Direct
2019-02-22	Restricted Stock Unit	$0	J	819	Disposed	2019-02-22	Common Stock (819)	Direct
2019-02-22	Stock Option (Right to Buy)	$49.65	M	6395	Disposed	2019-02-24	Common Stock (6395)	Direct

Footnotes

F1: The stock option was automatically exercised on a net share settlement basis immediately before its expiration, in accordance with its terms. The Company delivered to the reporting person the number of shares underlying the stock option less the number of shares having a Fair Market Value on the date of such exercise equal to (i) the aggregate exercise price for the stock option and (ii) the amount necessary to satisfy any federal, state and local withholding taxes related to such exercise.

F2: This option was previously reported as covering 6,250 shares at an exercise price of $49.65 per share, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

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 on the grant date]).

F4: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F5: The stock options become exercisable in four (4) equal annual installments commencing one year after the grant date of 02/24/09.