BIIB

SEC source: 0001127602-23-020235 · form4.xml · derivative · entry 4

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 315 shares

Expires 2023-07-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on July 1, 2020 and vested in three equal installments on each anniversary of the grant date.

SEC source: 0001127602-23-020235 · form4.xml · nonDerivative · entry 2

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 3,005.0915

SEC source: 0001127602-23-020235 · form4.xml · nonDerivative · entry 1

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 3,158.0915

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-019548 · form4.xml · nonDerivative · entry 1

SHERWIN STEPHEN A · CIK 0001079462 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,738

SEC source: 0001127602-23-019547 · form4.xml · nonDerivative · entry 1

Rowinsky Eric K · CIK 0001318886 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,174

SEC source: 0001127602-23-019546 · form4.xml · nonDerivative · entry 1

Mantas Jesus B · CIK 0001777331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,048

SEC source: 0001127602-23-019545 · form4.xml · nonDerivative · entry 1

LANGER SUSAN · CIK 0001982640 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,419.1

SEC source: 0001127602-23-019543 · form4.xml · nonDerivative · entry 1

HAWKINS WILLIAM A · CIK 0001106508 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,150

SEC source: 0001127602-23-019542 · form4.xml · nonDerivative · entry 1

Freire Maria C · CIK 0001547999 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,105

SEC source: 0001127602-23-019541 · form4.xml · nonDerivative · entry 1

DORSA CAROLINE · CIK 0001181174 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 24,822

SEC source: 0001127602-23-014148 · form4.xml · derivative · entry 2

Keeney Adam · CIK 0001973607 · Head of Corporate Development

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,815

Underlying: Common Stock · 2,815 shares

Expires 2026-05-01

F1 · derivative.exercise_date: The restricted stock units vest in three equal yearly installments beginning on the first anniversary of the grant date of May 1, 2023.

SEC source: 0001127602-23-014146 · form4.xml · nonDerivative · entry 1

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 8,482.716

F1 · balance_after: Includes 91.6992 shares acquired under the Biogen Inc. employee stock purchase plan on 3/31/2023.

SEC source: 0001127602-23-012691 · form4.xml · nonDerivative · entry 1

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 2,843.0915

F1 · price: Includes 91.6992 shares acquired under the Biogen Inc. employee stock purchase plan.

SEC source: 0001127602-23-012361 · form4.xml · derivative · entry 3

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 240

Underlying: Common Stock · 239 shares

Expires 2024-04-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_date: This award was granted to the reporting person on April 1, 2021. The remaining portion of the award vests in equal installments on each of the second and third anniversary of the grant date.

SEC source: 0001127602-23-012361 · form4.xml · nonDerivative · entry 2

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,702.2903

SEC source: 0001127602-23-012361 · form4.xml · nonDerivative · entry 1

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,818.2903

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: Includes 91.6992 shares acquired under the Biogen Inc. employee stock purchase plan.

SEC source: 0001127602-23-011661 · form4.xml · nonDerivative · entry 1

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,842.3923

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended.

SEC source: 0001127602-23-009142 · form4.xml · derivative · entry 5

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 341 shares

Expires 2023-03-02

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

F2 · derivative.exercise_date: This award was granted to the reporting person on March 2, 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]).

SEC source: 0001127602-23-009142 · form4.xml · derivative · entry 4

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 341

Underlying: Common Stock · 297 shares

Expires 2023-03-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_date: This award was granted to the reporting person on March 2, 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]).

SEC source: 0001127602-23-009142 · form4.xml · nonDerivative · entry 3

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,410.3923

SEC source: 0001127602-23-009142 · form4.xml · nonDerivative · entry 2

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,554.3923

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-009142 · form4.xml · nonDerivative · entry 1

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,257.3923

F1 · kind: Represents shares withheld to satisfy the withholding tax liability due upon vesting of shares, as previously disclosed by reporting person on January 27, 2023.

SEC source: 0001127602-23-006524 · form4.xml · derivative · entry 4

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 908

Underlying: Common Stock · 426 shares

Expires 2024-02-18

F2 · kind: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. 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]).

SEC source: 0001127602-23-006524 · form4.xml · derivative · entry 3

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,334

Underlying: Common Stock · 480 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. 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]).

SEC source: 0001127602-23-006524 · form4.xml · nonDerivative · entry 2

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,099.2903

SEC source: 0001127602-23-006524 · form4.xml · nonDerivative · entry 1

Murphy Nicole · CIK 0001910644 · Head of Pharm Ops and Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,579.2903

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-006527 · form4.xml · derivative · entry 4

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 874

Underlying: Common Stock · 408 shares

Expires 2024-02-18

F2 · kind: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of Restricted Stock Units ("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]).

SEC source: 0001127602-23-006527 · form4.xml · derivative · entry 3

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,282

Underlying: Common Stock · 460 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of Restricted Stock Units ("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]).

SEC source: 0001127602-23-006527 · form4.xml · nonDerivative · entry 2

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,800.3923

SEC source: 0001127602-23-006527 · form4.xml · nonDerivative · entry 1

Singhal Priya · CIK 0001769608 · Head of Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,951.3923

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-006522 · form4.xml · derivative · entry 4

MCDONNELL MICHAEL R · CIK 0001121897 · EVP, Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,836

Underlying: Common Stock · 2,271 shares

Expires 2024-02-18

F2 · kind: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006522 · form4.xml · derivative · entry 3

MCDONNELL MICHAEL R · CIK 0001121897 · EVP, Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,107

Underlying: Common Stock · 2,561 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006522 · form4.xml · nonDerivative · entry 2

MCDONNELL MICHAEL R · CIK 0001121897 · EVP, Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,586

SEC source: 0001127602-23-006522 · form4.xml · nonDerivative · entry 1

MCDONNELL MICHAEL R · CIK 0001121897 · EVP, Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,147

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-006519 · form4.xml · derivative · entry 4

Kramer Robin · CIK 0001609222 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 968

Underlying: Common Stock · 454 shares

Expires 2024-02-18

F2 · kind: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006519 · form4.xml · derivative · entry 3

Kramer Robin · CIK 0001609222 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,422

Underlying: Common Stock · 512 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006519 · form4.xml · nonDerivative · entry 2

Kramer Robin · CIK 0001609222 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,331.7483

SEC source: 0001127602-23-006519 · form4.xml · nonDerivative · entry 1

Kramer Robin · CIK 0001609222 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,843.7483

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-006513 · form4.xml · derivative · entry 4

Izzar Rachid · CIK 0001875506 · Head of Global Product Strat.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,454

Underlying: Common Stock · 681 shares

Expires 2024-02-18

F2 · kind: This number represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. 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]).

SEC source: 0001127602-23-006513 · form4.xml · derivative · entry 3

Izzar Rachid · CIK 0001875506 · Head of Global Product Strat.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,135

Underlying: Common Stock · 767 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. 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]).

SEC source: 0001127602-23-006513 · form4.xml · nonDerivative · entry 2

Izzar Rachid · CIK 0001875506 · Head of Global Product Strat.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,117

SEC source: 0001127602-23-006513 · form4.xml · nonDerivative · entry 1

Izzar Rachid · CIK 0001875506 · Head of Global Product Strat.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,884

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-006507 · form4.xml · derivative · entry 4

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,386

Underlying: Common Stock · 1,590 shares

Expires 2024-02-18

F2 · kind: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006507 · form4.xml · derivative · entry 3

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,976

Underlying: Common Stock · 1,792 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006507 · form4.xml · nonDerivative · entry 2

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,280.0168

SEC source: 0001127602-23-006507 · form4.xml · nonDerivative · entry 1

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,072.0168

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-23-006502 · form4.xml · derivative · entry 4

ALEXANDER SUSAN H · CIK 0001263839 · EVP Chief Legal Off & Corp Sec

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,626

Underlying: Common Stock · 1,702 shares

Expires 2024-02-18

F2 · kind: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 12, 2020. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006502 · form4.xml · derivative · entry 3

ALEXANDER SUSAN H · CIK 0001263839 · EVP Chief Legal Off & Corp Sec

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,328

Underlying: Common Stock · 1,920 shares

Expires 2024-02-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This award was granted to the reporting person on February 12, 2020. The number of RSUs reported represented the maximum possible number of shares that were 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]).

SEC source: 0001127602-23-006502 · form4.xml · nonDerivative · entry 2

ALEXANDER SUSAN H · CIK 0001263839 · EVP Chief Legal Off & Corp Sec

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,911

SEC source: 0001127602-23-006502 · form4.xml · nonDerivative · entry 1

ALEXANDER SUSAN H · CIK 0001263839 · EVP Chief Legal Off & Corp Sec

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 46,840

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.