Ginger Gregory - 10 Feb 2023 Form 4 Insider Report for BIOGEN INC. (BIIB)

Role: EVP, Human Resources
Signature: /s/ Wendell Taylor, attorney in fact for Ginger Gregory
Issuer symbol: BIIB
Transactions as of: 10 Feb 2023
Net transactions value: -$946,508
Form type: 4
Filing time: 14 Feb 2023, 20:44:01 UTC
Previous filing: 10 Feb 2023
Next filing: 22 Feb 2023
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	BIIB	Common Stock	Options Exercise	$0	+2,158	+21%	$0.000000	12,321	10 Feb 2023	Direct
transaction	BIIB	Common Stock	Tax liability	$185,522	-648	-5.3%	$286.30	11,673	10 Feb 2023	Direct
transaction	BIIB	Common Stock	Options Exercise	$0	+1,132	+9.7%	$0.000000	12,805	10 Feb 2023	Direct
transaction	BIIB	Common Stock	Tax liability	$156,892	-548	-4.3%	$286.30	12,257	10 Feb 2023	Direct
transaction	BIIB	Common Stock	Tax liability	$604,093	-2,110	-17%	$286.30	10,147	10 Feb 2023	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	BIIB	Restricted Stock Unit	Options Exercise	$0	-2,158	-33%	$0.000000	4,317	10 Feb 2023	Common Stock	2,158	$0.000000	Direct	F2
transaction	BIIB	Restricted Stock Unit	Options Exercise	$0	-1,132	-45%	$0.000000	1,384	10 Feb 2023	Common Stock	1,132	$0.000000	Direct	F3
transaction	BIIB	Restricted Stock Unit	Other	$0	-1,384	-100%	$0.000000^*	0	10 Feb 2023	Common Stock	1,384	$0.000000	Direct	F3, F4

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents shares withheld to satisfy the withholding tax liability due upon vesting of shares, as previously disclosed by reporting person on January 27, 2023.
F2	The restricted stock units vest in three equal yearly installments beginning on the first anniversary of the grant date of February 10, 2022.
F3	This award was granted to the reporting person on February 12, 2020. 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	This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.