BIOGEN INC. — Director's Dealing 2026

Feb 10, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2026-02-06

Reporting Person: Godbout Sean (Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-02-06	Common Stock	M	257	—	Acquired	751.6667	Direct
2026-02-06	Common Stock	F	76	$201.18	Disposed	675.6667	Direct
2026-02-06	Common Stock	M	305	—	Acquired	980.6667	Direct
2026-02-06	Common Stock	F	103	$201.18	Disposed	877.6667	Direct
2026-02-06	Common Stock	M	517	—	Acquired	1394.6667	Direct
2026-02-06	Common Stock	F	180	$201.18	Disposed	1214.6667	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-02-06	Restricted Stock Unit	$0	M	257	Disposed	2026-02-08	Common Stock (257)	Direct
2026-02-06	Restricted Stock Unit	$0	M	305	Disposed	2027-02-07	Common Stock (305)	Direct
2026-02-06	Restricted Stock Unit	$0	M	517	Disposed	2028-02-06	Common Stock (517)	Direct

Footnotes

F1: The restricted stock units vest in three (3) equal annual installments commencing one year after the grant date of 02/08/2023.

F2: The restricted stock units vest in three (3) equal annual installments commencing one year after the grant date of 02/07/2024.

F3: The restricted stock units vest in three (3) equal annual installments commencing one year after the grant date of 02/06/2025.