BIIB

SEC source: 0001127602-18-007393 · form4.xml · nonDerivative · entry 1

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,296.3821

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

SEC source: 0001127602-18-007209 · form4.xml · derivative · entry 4

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,254

Underlying: Common Stock · 787 shares

Expires 2020-02-15

F2 · shares: 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: 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]).

SEC source: 0001127602-18-007209 · form4.xml · derivative · entry 3

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,041

Underlying: Common Stock · 1,339 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007209 · form4.xml · nonDerivative · entry 2

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,590.3821

SEC source: 0001127602-18-007209 · form4.xml · nonDerivative · entry 1

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,186.3821

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: 0001127602-18-007215 · form4.xml · derivative · entry 4

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,002

Underlying: Common Stock · 3,144 shares

Expires 2020-02-15

F2 · shares: 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: 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]).

SEC source: 0001127602-18-007215 · form4.xml · derivative · entry 3

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,146

Underlying: Common Stock · 5,354 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007215 · form4.xml · nonDerivative · entry 2

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,356.458

SEC source: 0001127602-18-007215 · form4.xml · nonDerivative · entry 1

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,233.458

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: 0001127602-18-007206 · form4.xml · derivative · entry 4

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,674

Underlying: Common Stock · 864 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007206 · form4.xml · derivative · entry 3

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,538

Underlying: Common Stock · 1,472 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007206 · form4.xml · nonDerivative · entry 2

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,411.819

SEC source: 0001127602-18-007206 · form4.xml · nonDerivative · entry 1

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,853.819

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 56.628 shares, 14.094 shares, 12.029 shares and 7.625 shares acquired under the Biogen Inc. employee stock purchase plan on 3/31/2017, 6/30/2017, 9/29/2017 and 12/29/2017, respectively.

SEC source: 0001127602-18-007195 · form4.xml · derivative · entry 4

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,442

Underlying: Common Stock · 1,006 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007195 · form4.xml · derivative · entry 3

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,448

Underlying: Common Stock · 1,712 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007195 · form4.xml · nonDerivative · entry 2

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,898.359

SEC source: 0001127602-18-007195 · form4.xml · nonDerivative · entry 1

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,407.359

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 39.569 shares and 39.790 shares acquired under the Biogen Inc. employee stock purchase plan on 9/29/2017 and 12/29/2017, respectively.

SEC source: 0001127602-18-007189 · form4.xml · derivative · entry 4

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 514

Underlying: Common Stock · 95 shares

Expires 2020-02-15

F2 · shares: 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: 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]).

SEC source: 0001127602-18-007189 · form4.xml · derivative · entry 3

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 609

Underlying: Common Stock · 161 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007189 · form4.xml · nonDerivative · entry 2

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,544.3601

SEC source: 0001127602-18-007189 · form4.xml · nonDerivative · entry 1

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,600.3601

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: 0001127602-18-007183 · form4.xml · derivative · entry 4

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,442

Underlying: Common Stock · 1,006 shares

Expires 2020-02-15

F2 · shares: 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: 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]).

SEC source: 0001127602-18-007183 · form4.xml · derivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,448

Underlying: Common Stock · 1,712 shares

Expires 2020-02-15

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: 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]).

SEC source: 0001127602-18-007183 · form4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,460

SEC source: 0001127602-18-007183 · form4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,970

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: 0001127602-18-006193 · form4.xml · derivative · entry 2

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,840

Underlying: Common Stock · 11,840 shares

Expires 2021-02-12

F2 · derivative.exercise_date: 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: 0001127602-18-006193 · form4.xml · derivative · entry 1

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,735

Underlying: Common Stock · 4,735 shares

Expires 2020-02-12

F1 · derivative.exercise_date: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

SEC source: 0001127602-18-006188 · form4.xml · derivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,110

Underlying: Common Stock · 10,110 shares

Expires 2021-02-12

F2 · derivative.exercise_date: 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: 0001127602-18-006188 · form4.xml · derivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,045

Underlying: Common Stock · 4,045 shares

Expires 2020-02-12

F1 · derivative.exercise_date: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

SEC source: 0001127602-18-006187 · form4.xml · derivative · entry 2

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,390

Underlying: Common Stock · 1,390 shares

Expires 2021-02-12

F2 · derivative.exercise_date: 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: 0001127602-18-006187 · form4.xml · derivative · entry 1

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 345

Underlying: Common Stock · 345 shares

Expires 2020-02-12

F1 · derivative.exercise_date: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

SEC source: 0001127602-18-006186 · form4.xml · derivative · entry 2

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,470

Underlying: Common Stock · 9,470 shares

Expires 2021-02-12

F2 · derivative.exercise_date: 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: 0001127602-18-006186 · form4.xml · derivative · entry 1

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,790

Underlying: Common Stock · 3,790 shares

Expires 2020-02-12

F1 · derivative.exercise_date: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

SEC source: 0001127602-18-006184 · form4.xml · derivative · entry 2

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,680

Underlying: Common Stock · 5,680 shares

Expires 2021-02-12

F2 · derivative.exercise_date: 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: 0001127602-18-006184 · form4.xml · derivative · entry 1

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,275

Underlying: Common Stock · 2,275 shares

Expires 2020-02-12

F1 · derivative.exercise_date: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

SEC source: 0001127602-18-006182 · form4.xml · derivative · entry 1

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,320

Underlying: Common Stock · 36,320 shares

Expires 2021-02-12

F1 · derivative.exercise_date: 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: 0001127602-18-006179 · form4.xml · derivative · entry 7

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,418

Underlying: Common Stock · 1,398 shares

Expires 2019-02-12

F4 · derivative.exercise_date: 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-fourth of these RSUs are eligible to vest each year for four years, beginning two years from the date of grant. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen Idec 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]).

SEC source: 0001127602-18-006179 · form4.xml · derivative · entry 6

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,816

Underlying: Common Stock · 2,012 shares

Expires 2019-02-12

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.

F4 · derivative.exercise_date: 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-fourth of these RSUs are eligible to vest each year for four years, beginning two years from the date of grant. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen Idec 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]).

SEC source: 0001127602-18-006179 · form4.xml · derivative · entry 5

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,290

Underlying: Common Stock · 8,290 shares

Expires 2021-02-12

F3 · derivative.exercise_date: 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: 0001127602-18-006179 · form4.xml · derivative · entry 4

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,315

Underlying: Common Stock · 3,315 shares

Expires 2020-02-12

F2 · derivative.exercise_date: The restricted stock units will vest in 2 annual installments. One-third will vest on the first anniversary of the grant date and two-thirds will vest on the second anniversary of the grant date.

SEC source: 0001127602-18-006179 · form4.xml · nonDerivative · entry 3

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,847.3821

SEC source: 0001127602-18-006179 · form4.xml · nonDerivative · entry 2

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,565.3821

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: 0001127602-18-006179 · form4.xml · nonDerivative · entry 1

Sandrock Alfred · CIK 0001577061 · EVP, Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,553.3821

F1 · balance_after: Includes 91.527 shares acquired under the Biogen Inc. Employee Stock Purchase Plan on 3/31/2017.

SEC source: 0001127602-18-001563 · form4.xml · derivative · entry 3

PANGIA ROBERT W · CIK 0001236188 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 5,832 shares

Expires 2018-06-18

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.

F2 · derivative.exercise_price: This option was previously reported as covering 5,700 shares at an exercise price of $59.17 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.

F1 · kind: Exercise/sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

F2 · shares: This option was previously reported as covering 5,700 shares at an exercise price of $59.17 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.

F2 · derivative.underlying_shares: This option was previously reported as covering 5,700 shares at an exercise price of $59.17 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.

SEC source: 0001127602-18-001563 · form4.xml · nonDerivative · entry 2

PANGIA ROBERT W · CIK 0001236188 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,707

F1 · kind: Exercise/sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-18-001563 · form4.xml · nonDerivative · entry 1

PANGIA ROBERT W · CIK 0001236188 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,539

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 · kind: Exercise/sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-18-001115 · form4.xml · derivative · entry 2

CAPELLO JEFFREY D · CIK 0001224108 · EVP & Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,390

Underlying: Common Stock · 5,390 shares

Expires not disclosed

F2 · shares: The number of performance stock units ("PSUs") reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. The actual number of PSUs that will vest will be determined based upon achievement of three-year performance goals adopted by the Compensation and Management Development Committee of the Board of Directors (the "Committee") in the first quarter of 2018.

F3 · derivative.exercise_date: All eligible PSUs will vest on the later of January 2, 2021 or the date of the Committee's determination of the degree to which the annual performance goals have been satisfied.

F3 · derivative.expiration_date: All eligible PSUs will vest on the later of January 2, 2021 or the date of the Committee's determination of the degree to which the annual performance goals have been satisfied.

SEC source: 0001127602-18-001115 · form4.xml · derivative · entry 1

CAPELLO JEFFREY D · CIK 0001224108 · EVP & Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,980

Underlying: Common Stock · 8,980 shares

Expires 2021-01-02

F1 · derivative.exercise_date: 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: 0001127602-18-000128 · form4.xml · nonDerivative · entry 1

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,879.458

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

SEC source: 0001127602-17-033939 · form4.xml · derivative · entry 2

Guindo Chirfi · CIK 0001722753 · EVP Glob. Mkt Acc & Cust Innov

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,755

Underlying: Common Stock · 1,755 shares

Expires 2020-12-01

F1 · derivative.exercise_date: 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]).