BIOGEN INC. — Director's Dealing 2023

Sep 6, 2023

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2023-09-01

Reporting Person: MCDONNELL MICHAEL R (EVP, Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2023-09-01	Common Stock	M	2682	—	Acquired	12829	Direct
2023-09-01	Common Stock	F	1372	$267.17	Disposed	11457	Direct
2023-09-01	Common Stock	M	2603	—	Acquired	14060	Direct
2023-09-01	Common Stock	F	1332	$267.17	Disposed	12728	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2023-09-01	Restricted Stock Unit	$0	M	2682	Disposed	2023-09-01	Common Stock (2682)	Direct
2023-09-01	Restricted Stock Unit	$0	M	2603	Disposed	2023-09-01	Common Stock (2603)	Direct
2023-09-01	Restricted Stock Unit	$0	J	2763	Disposed	2023-09-01	Common Stock (2763)	Direct

Footnotes

F1: The restricted stock units vested in three (3) equal annual installments commencing one year after the grant date of 09/01/2020.

F2: 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 average closing stock price for the 30 calendar days following and including the grant date and 30 calendar days prior to and including such vesting date]).

F3: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.