Biogen Inc. Executive Severance Policy - U.S. Executive Vice President, as amended effective July 13, 2020

As an Executive Vice President, you are entitled to severance benefits in the event your employment is terminated by Biogen other than For Cause or for reason of death or Disability (as these terms are defined in the Biogen Inc. 2017 Omnibus Equity Plan, as amended from time to time, or any successor plan there to (“OEP”).

Your severance benefits are comprised of (i) a lump sum payment (as calculated below), (ii) upon completion of the appropriate forms, continuation of your participation in Biogen’s group medical and dental insurance plans, to the same extent permitted by COBRA and to the same extent such insurance is then provided to regular employees of Biogen, including payment by you of a portion of the insurance premiums (i.e., the “Insurance Benefit”) and (iii) the reasonable cost of up to 12 months of executive-level outplacement services from a recognized provider of such services selected by Biogen, at the expense of Biogen (upon receipt of appropriate documentation). Except as otherwise prohibited by local law, any severance payments contemplated by this plan will be reduced by the number of weeks’ pay corresponding to any periods during which the employee is not actively working, including statutory or contractual notice periods and any garden or other leave.

The lump sum severance payment is calculated as follows:

where:    A is the number of full years of service with Biogen (but A x 2 may not exceed 9), and B is the monthly equivalent of your target annual cash compensation at the time of your termination (i.e., one-twelfth of the sum of your then annual base salary plus target annual bonus).

The following are examples of how the lump sum payment and Insurance Benefit Period are determined:

If at any time within two years following a Corporate Transaction or Corporate Change in Control (as these terms are defined in Biogen’s OEP) your employment is terminated by Biogen

or the succeeding corporate entity, other than For Cause or for reason of death or Disability (as these terms are defined in Biogen’s OEP), or you experience an Involuntary Employment Action (defined below) and as a result you terminate your employment with Biogen or the succeeding corporate entity, then, regardless of the length of your service with Biogen and the succeeding corporate entity, and in lieu of the formula set forth above, you will receive a lump sum payment equivalent to 24 months of your target annual cash compensation at the time of your termination or at the time of a Corporate Transaction or Corporate Change in Control, whichever is higher. In addition, you will be entitled to continue participating in Biogen’s group medical and dental plans for 24 months, unless you become eligible to participate in another employer’s medical and dental plans before that date. The term “Involuntary Employment Action” shall have the definition set forth in Biogen’s OEP, provided, however, that the term “Corporate Transaction” used in that definition shall be deemed to mean either a Corporate Transaction or Change in Control, as the case may be, and provided also that prior to your termination of employment you have notified the Chief Legal Counsel or the Head of Human Resources of Biogen in writing of the basis for your Involuntary Employment Action, you have given such notice within one year of the circumstances giving rise to your Involuntary Employment Action and Biogen does not cure such circumstances within 30 days after the date of your notice.

Payment and provision of all the benefits provided under this arrangement are conditioned on your execution and delivery of all necessary forms and an irrevocable general release in favor of Biogen, in form and substance reasonably acceptable to Biogen, with respect to any and all claims relating to your employment and the termination of your employment with Biogen. If you retire or voluntarily terminate your employment with Biogen, or Biogen terminates your employment For Cause or for reason of death or Disability (as these terms are defined in Biogen’s OEP), or you do not provide the requisite general release, you will not be eligible to receive the severance benefits described above.

If all other conditions of this arrangement are met, a lump sum payment (less applicable taxes and other mandatory deductions as required by law) will be paid to you following the termination of your employment, no later than the first to occur of: a) 90 days following your termination of your employment with Biogen and b) March 15 of the year following the calendar year in which termination of employment occurs, unless you are a “specified employee” as defined in Section 409A of the Internal Revenue Code of 1986, as amended (i.e., “Section 409A”). (If all preconditions to payment, including the delivery of an irrevocable general release, are not satisfied prior to the earlier of these two dates, payment to you may be delayed and you may incur additional tax liabilities under Section 409A.) If you are a “specified employee”, to the extent required by Section 409A, payment will not be made to you before the date which is six months after you “separate from service” (or, if earlier, your date of death or Disability) unless the payment qualifies as excepted welfare benefits under Section 409A, does not constitute a “deferral of compensation” under Section 409A or is otherwise not subject to the requirements of Section 409A. Each payment made under this arrangement shall be treated as a separate payment and the right to receive a series of installment payments under this arrangement shall be treated as a right to a series of separate payments.

The Insurance Benefit will be paid on a monthly basis and will continue until the earlier of (i) the date you become eligible to participate in the medical and dental insurance plan of another employer or (ii) the date that is [12 + (A x 2)] months, but not more than 21 months (or 24 months in the case of a Corporate Transaction or Change in Control), following the termination of your employment with Biogen (the “Insurance Benefit Period”). You will have the right, at your own expense, to continue your participation in Biogen’s group medical and dental insurance plans at the expiration of the Insurance Benefit Period, pursuant to the provisions of COBRA, but only for an 18-month period that will be deemed to have commenced at the start of your severance. You will only be entitled to receive the Insurance Benefit if you timely and properly elect continuation coverage under COBRA. If Biogen determines in its sole discretion that it cannot provide the Insurance Benefit without the possibility of violating applicable law (including, without limitation, the Patient Protection and Affordable Care Act) or it or you incurring additional taxes, including but not limited to under Section 105(h) of the Internal Revenue Code, Biogen will in lieu thereof provide to you a taxable monthly payment in an amount equal to the monthly COBRA premium that Biogen Idec would have otherwise paid under this arrangement in respect of the Insurance Benefit (which amount will be based on the premium for the first month of COBRA coverage) for the Insurance Benefit Period in equal installments in accordance with Biogen’s normal payroll practices.

Biogen shall administer and shall have the discretionary authority to adopt rules for the management and operation of this arrangement, to interpret the provisions of the arrangement and to construe the terms of the severance arrangement in its sole discretion. The decision of Biogen, or the duly authorized delegate, is final and conclusive for all purposes.

The severance arrangement may be amended, modified, suspended or terminated by Biogen at any time; provided that the severance arrangement may not be amended or terminated without your written consent for a period of two years following a Corporate Transaction or a Change in Control.

This arrangement is unfunded. This arrangement will benefit and bind Biogen and its successors and permitted assigns and you and your heirs, executors and legal representatives. You do not have any right to transfer or assign your benefits under this arrangement.

This arrangement shall be construed, administered and enforced according to the laws of the State of Delaware, except to the extent that such laws are preempted by the federal laws of the United States of America.