The Board of Directors of Biogen Inc. is soliciting your proxy to vote at our 2015 annual meeting of stockholders (Annual Meeting) to be held at 9:00 a.m., local time, on Wednesday, June 10, 2015 at our offices located at 115 Broadway, Cambridge, Massachusetts 02142 for the purposes summarized in the accompanying Notice of 2015 Annual Meeting of Stockholders. Our 2014 Annual Report on Form 10-K is also available with this Proxy Statement.

In March 2015, we changed our corporate legal name from Biogen Idec Inc. to Biogen Inc. References in this Proxy Statement to “Biogen” or the “Company,” “we”, “us” and “our” refer to Biogen Inc.

Who can vote?

Each share of our common stock that you own as of the close of business on the record date of April 15, 2015 (Record Date) entitles you to one vote on each matter to be voted upon at the Annual Meeting. As of the Record Date, 235,230,221 shares of our common stock were outstanding and entitled to vote. We are making this Proxy Statement and other Annual Meeting materials available on the Internet or, upon request, sending printed versions of these materials on or about April 30, 2015 to all stockholders of record as of the Record Date. For 10 days before the Annual Meeting, a list of stockholders entitled to vote will be available for inspection at our offices located at 225 Binney Street, Cambridge, Massachusetts 02142. If you would like to review the list, please call our Investor Relations department at (781) 464-2442.

Who can attend the Annual Meeting?

Attendance at the Annual Meeting will be limited to stockholders of Biogen as of the Record Date (or their authorized representatives). If your shares are held by a bank, broker or other nominee, please bring to the Annual Meeting your bank or brokerage statement evidencing your beneficial ownership of Biogen stock to gain admission to the Annual Meeting. Stockholders who plan to attend the Annual Meeting must present valid photo identification. Stockholders of record will be verified against an official list available at the registration area. We reserve the right to deny admittance to anyone who cannot show sufficient proof of share ownership as of the Record Date.

How do proxies work?

Our Board of Directors is asking for your proxy authorizing the individuals named as proxies to vote your shares at the Annual Meeting in the manner you direct. You may abstain from voting on any matter. If you submit your proxy without specifying your voting instructions, we will vote your shares as follows:

Shares represented by valid proxies received in time for the Annual Meeting and not revoked before the Annual Meeting will be voted at the Annual Meeting. You can revoke your proxy and change your vote in the manner described below (under the heading “How can I change my vote?”). If your shares are held through a bank, broker or other nominee, please follow the instructions that you were provided by your bank, broker or other nominee.

How do I vote?

It is important that your shares are represented at the Annual Meeting, whether or not you attend the Annual Meeting in person.

If you are a registered stockholder (also called a “record holder”), there are four ways to vote:

If your shares are held in a brokerage account in your broker’s name (this is called “street name”), please follow the voting instructions provided by your bank, broker or other nominee. In most cases, you may submit voting instructions by telephone or by Internet to your bank, broker or other nominee, or you can sign, date and return a voting instruction form to your bank, broker or other nominee. If you provide specific voting instructions by telephone, Internet or mail, your bank, broker or other nominee must vote your shares as you have directed. If you wish to vote in person at the Annual Meeting, you must request a legal proxy from your bank, broker or other nominee.

Why did I receive a one-page notice in the mail regarding the Internet availability of proxy materials instead of a full set of proxy materials?

We have elected to provide access to our proxy materials on the Internet, consistent with the rules of the Securities and Exchange Commission (SEC). Accordingly, in most instances we are mailing a Notice of Internet Availability of Proxy Materials to our stockholders. You can access our proxy materials on the website referred to in the Notice of Internet Availability of Proxy Materials or you may request printed versions of our proxy materials for the Annual Meeting. Instructions on how to access our proxy materials on the Internet or to request printed versions are provided in the Notice of Internet Availability of Proxy Materials. In addition, you may request to receive proxy materials in printed form by mail or electronically by email on an ongoing basis.

What does it mean if I receive more than one notice regarding the Internet availability of proxy materials or more than one set of printed proxy materials?

If you hold your shares in more than one account, you may receive a separate Notice of Internet Availability of Proxy Materials or a separate set of printed proxy materials, including a separate proxy card or voting instruction form, for each account. To ensure that all of your shares are voted, please vote by telephone or by Internet or sign, date and return a proxy card or voting instruction form for each account.

How can I change my vote?

You may revoke your proxy and change your vote at any time before the Annual Meeting by:

Only your latest vote, in whatever form, will be counted.

Will my shares be counted if I do not vote?

If you are a record holder and do not vote by telephone, through the Internet or by signing, dating and returning a printed proxy card, your shares will not be voted.

If you are the beneficial owner of shares held in “street name,” your bank, broker or other nominee, as the record holder of the shares, is required to vote those shares in accordance with your instructions. If no voting instructions are provided, these record holders can vote your shares only on discretionary, or routine, matters and not on non-discretionary, or non-routine, matters. Uninstructed shares whose votes cannot be counted on non-routine matters result in what are commonly referred to as “broker non-votes.”

The proposal to ratify the selection of our independent registered public accounting firm is a routine matter and our other proposals are non-routine matters. If you do not give your broker voting instructions, your broker (1) will be entitled to vote your shares on the proposal to ratify the selection of our independent registered public accounting firm and (2) will not be entitled to vote your shares on the other proposals. We urge you to provide instructions to your bank, broker or other nominee so that your votes may be counted on all of these important matters.

You should vote your shares by telephone or by Internet according to the instructions provided by your bank, broker or other nominee or by signing, dating and returning a printed voting instruction form to your bank, broker or other nominee to ensure that your shares are voted on your behalf.

How many shares must be present to hold the Annual Meeting?

A majority of our issued and outstanding shares of common stock as of the Record Date must be present at the Annual Meeting to hold the Annual Meeting and conduct business. This is called a quorum. Shares voted in the manner described above (under the heading “How do I vote?”) will be counted as present at the Annual Meeting. Shares that are present and entitled to vote on one or more of the matters to be voted upon are counted as present for establishing a quorum. If a quorum is not present, we expect that the Annual Meeting will be adjourned until we obtain a quorum.

What vote is required to approve each proposal and how are votes counted?

Are there other matters to be voted on at the Annual Meeting?

We do not know of any other matters that may come before the Annual Meeting. If any other matters are properly presented at the Annual Meeting, your proxy authorizes the individuals named as proxies to vote, or otherwise act, in accordance with their best judgment.

Where do I find the voting results of the Annual Meeting?

We will publish the voting results of the Annual Meeting in a Current Report on Form 8-K filed with the SEC within four

business days after the end of the Annual Meeting. You may request a copy of this Form 8-K by contacting Investor Relations, Biogen Inc., 225 Binney Street, Cambridge, Massachusetts 02142, (781) 464-2442. You will also be able to find a copy of this Form 8-K on the Internet through the SEC’s electronic data system called EDGAR at www.sec.gov or through the “Investors” section of our website, www.biogen.com.

Who should I call if I have any questions?

If you have any questions or require any assistance with voting your shares, please contact your bank, broker or other nominee holding your shares, or our Investor Relations department at (781) 464-2442.

Important Notice Regarding the Availability of Proxy Materials for Annual Meeting of Stockholders

To Be Held on June 10, 2015:

The Notice of 2015 Annual Meeting of Stockholders, Proxy Statement, and 2014 Annual Report on Form 10-K are

available at the following website: www.edocumentview.com/BIIB.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE ELECTION OF EACH DIRECTOR NOMINEE NAMED ABOVE.

Our Audit Committee is directly responsible for the appointment, compensation, retention and oversight of the independent registered public accounting firm retained to audit our financial statements. The Audit Committee has selected PricewaterhouseCoopers LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2015. PricewaterhouseCoopers has served as our independent registered public accounting firm since 2003. In order to assure continuing auditor independence, the Audit Committee periodically considers whether there should be a rotation of the independent registered public accounting firm. Further, in conjunction with the rotation of the auditing firm’s lead engagement partner required by applicable SEC rules, the Audit Committee and its chairperson are directly involved in the selection of PricewaterhouseCoopers’ new lead engagement partner. The Audit Committee believes that the continued retention of PricewaterhouseCoopers at this time is in the best interest of Biogen and its stockholders.

Although stockholder approval of the Audit Committee’s selection of PricewaterhouseCoopers is not required, our Board of Directors believes that it is a matter of good corporate practice to solicit stockholder ratification of this selection. If our stockholders do not ratify the selection of PricewaterhouseCoopers as our independent registered public accounting firm, the Audit Committee will reconsider its selection. Even if the selection is ratified, the Audit Committee always has the ability to change the engagement of PricewaterhouseCoopers if it considers that a change is in Biogen’s best interest. Representatives of PricewaterhouseCoopers will attend the Annual Meeting, have the opportunity to make a statement if they so desire, and be available to respond to appropriate questions.

Audit and Other Fees

The following table shows fees for professional audit services billed to us by PricewaterhouseCoopers for the audit of our annual consolidated financial statements for the years ended December 31, 2014 and December 31, 2013, and fees billed to us by PricewaterhouseCoopers for other services provided during 2014 and 2013:

Audit fees are fees for the audit of our 2014 and 2013 consolidated financial statements included in our Annual Reports on Form 10-K, reviews of our condensed consolidated financial statements included in our Quarterly Reports on Form 10-Q, review of the consolidated financial statements incorporated by reference into our outstanding registration statements, and statutory audit fees in overseas jurisdictions.

Audit-related fees are fees that principally relate to assurance and related services that are reasonably related to the performance of the audits and reviews of our consolidated financial statements, including audits of employee benefit plan information.

Tax fees are fees for tax compliance and planning services.

All other fees in 2014 include $11,061 of fees incurred for services provided in assessing the technical structure and format of reports submitted to government authorities to ensure compliance with applicable regulations (“Technical Compliance Services”). All other fees also include license fees for a web-based accounting research tool, which totaled $7,100 in 2014 and 2013, respectively.

Policy on Pre-Approval of Audit and Non-Audit Services

The Audit Committee has the sole authority to approve the scope of the audit and any audit-related services as well as all audit fees and terms. The Audit Committee must pre-approve any audit and non-audit services provided by our independent registered public accounting firm. The Audit Committee will not approve the engagement of the independent registered public accounting firm to perform any services that the independent registered public accounting firm would be prohibited from providing under applicable securities laws, The NASDAQ Stock Market, Inc. (NASDAQ) requirements or Public Company Accounting Oversight Board rules. In assessing whether to approve the use of our independent registered public accounting firm to provide permitted non-audit services, the Audit Committee tries to minimize relationships that could appear to impair the objectivity of our independent registered public accounting firm. The Audit Committee will approve permitted non-audit services by our independent registered public accounting firm only when it will be more effective or economical to have such services provided by our independent registered public accounting firm than by another firm.

The Audit Committee annually reviews and pre-approves the audit, audit-related, tax, and other permissible non-audit services that can be provided by the independent registered public accounting firm. After the annual review, any proposed services exceeding pre-set levels or amounts or additional services not previously approved requires separate pre-approval by the Audit Committee or the Chair of the Audit Committee. Any pre-approval decision made by the Chair of the Audit Committee is reported to the Audit Committee at the next regularly scheduled Audit Committee meeting. Our Chief Accounting Officer and Chief Financial Officer can approve up to an additional $50,000 in the aggregate per calendar year for categories of services that the Audit Committee (or the Chair through its delegated authority) has pre-approved.

All of the services provided by PricewaterhouseCoopers during 2014 were pre-approved in accordance with this policy, except for $11,061 of fees for Technical Compliance Services described above under the caption All other fees, which were subsequently ratified by the Audit Committee.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE RATIFICATION OF

THE SELECTION OF PRICEWATERHOUSECOOPERS LLP AS OUR INDEPENDENT REGISTERED PUBLIC

ACCOUNTING FIRM FOR THE FISCAL YEAR ENDING DECEMBER 31, 2015.

Our Compensation Discussion and Analysis, which appears later in this Proxy Statement, describes our executive compensation program and the compensation decisions that the Compensation Committee and our Board of Directors made with respect to the 2014 compensation of our named executive officers (listed in the Summary Compensation Table). As required pursuant to Section 14A of the Securities Exchange Act, our Board of Directors is asking that stockholders cast a non-binding, advisory vote FOR the following resolution:

“RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the Compensation Discussion and Analysis, compensation tables and narrative discussion, is hereby APPROVED.”

As we describe in our Compensation Discussion and Analysis, our executive compensation program embodies a pay-for-performance philosophy that supports our business strategy and aligns the interests of our executives with our stockholders. In particular, our compensation program rewards financial, strategic and operational performance and the goals set for each performance category support our long-range plans. In addition, to discourage excessive risk taking, we maintain policies for share ownership and

recoupment of compensation, we cap payments under our annual bonus plan, and we require multi-year vesting of long-term incentive awards.

In light of our strong performance in 2014, we believe that the compensation paid to our named executive officers was appropriate. Highlights of our 2014 performance include: our revenue, adjusted free cash flow and non-GAAP earnings per share for 2014 exceeded the targets we set for our compensation programs; and common stock price performance, a key determinant of payouts under our market stock units, increased 21% in 2014.

For the foregoing reasons, our Board of Directors is asking that stockholders support this proposal. Although the vote you are being asked to cast is non-binding, we value the views of our stockholders, and the Compensation Committee and our Board of Directors will consider the outcome of the vote when making future compensation decisions for our named executive officers.

We will hold a non-binding, advisory vote of our stockholders on the compensation of our named executive officers every year until the next required stockholder vote on the frequency of such advisory vote. The next stockholder vote on the frequency of such advisory vote currently is expected to be held at the 2017 annual meeting of stockholders.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE ADVISORY VOTE ON EXECUTIVE COMPENSATION.

At the Annual Meeting, stockholders will be asked to approve the adoption of our 2015 Employee Stock Purchase Plan (ESPP). The ESPP was adopted by our Board of Directors on December 10, 2014 and will become effective upon receiving stockholder approval at our Annual Meeting.

The purpose of the ESPP is to enable eligible employees of the Company and certain of its subsidiaries to use payroll deductions to purchase shares of our common stock and thereby acquire an ownership interest in the Company. The ESPP is intended to qualify as an “employee stock purchase plan” meeting the requirements of Section 423 of the Internal Revenue Code. If approved, the ESPP would replace the Biogen Idec Inc. 1995 Employee Stock Purchase Plan, which terminates on June 30, 2015.

The maximum aggregate number of shares of our common stock that may be purchased under the ESPP will be 6,200,000 (ESPP Share Pool), subject to adjustment as provided for in the ESPP. The ESPP Share Pool represents 2.64% of the total number of shares of our common stock outstanding as of April 10, 2015. In establishing the ESPP Share Pool, our Board of Directors considered the potential dilutive impact to stockholders, the projected participation rate over the ten-year term of the plan based on historic rates of participation under our existing employee stock purchase plan, equity plan guidelines established by certain proxy advisory firms and advice provided by Frederic W. Cook & Co., Inc., the compensation consultant to the Compensation Committee. For information about options and restricted stock units outstanding under our existing equity plans and the number of shares available for issuance under these plans, each as of December 31, 2014, please see “Equity Compensation Plan Information” elsewhere in this Proxy Statement.

The full text of the ESPP is set forth in Appendix A. The following description of certain features of the ESPP is qualified in its entirety by reference to the full text of the ESPP.

Summary of the ESPP

Administration. The ESPP will be administered by the Compensation Committee, which will have the authority to interpret and determine eligibility under the plan, prescribe forms, rules and procedures relating to the plan, and otherwise do all things necessary or appropriate to carry out the purposes of the plan. The Compensation Committee may

delegate its authority under the ESPP to a subcommittee comprised of one or more of its members, to members of our Board of Directors, or to officers or employees of the Company to the extent permitted by law.

Shares Subject to the Plan. As noted above, the ESPP Share Pool consists of 6,200,000 shares of our common stock, subject to adjustment, as described below. Shares delivered upon exercise of purchase rights under the ESPP may be either shares of authorized but unissued common stock, treasury stock, or common stock acquired in an open-market transaction. In the event of any change in our outstanding common stock by reason of a stock dividend, stock split, reverse stock split, split-up, recapitalization, merger, consolidation, reorganization, or other capital change, the aggregate number and type of shares available for purchase under the ESPP, the number and type of shares granted or purchasable during an offering period, and the purchase price per share under an outstanding purchase right will be appropriately adjusted in a manner that complies with Section 423 of the Internal Revenue Code.

If any purchase right granted under the ESPP expires or terminates for any reason without having been exercised in full or ceases for any reason to be exercisable in whole or in part, the unpurchased shares of common stock will again be available for purchase pursuant to offerings under the ESPP.

Eligibility. Participation in the ESPP will be limited to employees of Biogen and any of its designated subsidiaries (a) whose customary employment is for more than five months per calendar year, (b) who customarily work 20 hours or more per week, and (c) who satisfy the procedural enrollment and other requirements set forth in the ESPP. Under the ESPP, designated subsidiaries include any subsidiary (within the meaning of Section 424(f) of the Internal Revenue Code) of Biogen that has been designated by our Board of Directors or the Compensation Committee as eligible to participate in the plan.

No employee may be granted a purchase right under the ESPP if, immediately after the purchase right is granted, the employee would own (or, under applicable statutory attribution rules, would be deemed to own) stock possessing 5% or more of the total combined voting power or value of all classes of stock of the Company or any of its subsidiaries. In addition, employees who are citizens or residents of a foreign jurisdiction will not be eligible to participate in the

ESPP if the grant of a purchase right under the plan is prohibited under the laws of the foreign jurisdiction or compliance with the laws of the foreign jurisdiction would cause the plan to violate the requirements of Section 423 of the Internal Revenue Code. The Compensation Committee may establish additional eligibility requirements for offering periods that have not yet commenced that are not inconsistent with Section 423 of the Internal Revenue Code.

As of April 10, 2015, approximately 7,600 employees would be eligible to participate in the ESPP, including all of our executive officers.

General Terms of Participation.

Transferability. Purchase rights granted to participants under the ESPP are not assignable or transferable and may be exercised only by the participant during his or her lifetime.

Amendment and Termination of the ESPP. Our Board of Directors has the right to amend the ESPP to any extent and in any manner it may deem advisable, provided that any amendment that would be treated as the adoption of a new plan for purposes of Section 423 of the Internal Revenue Code will require stockholder approval.

Our Board of Directors also has the right at any time to suspend or terminate the ESPP. In connection with such a termination or suspension, our Board of Directors may provide, in its discretion, either that the outstanding purchase rights will be exercisable on the purchase date for the applicable offering period (or such earlier date as the Board of Directors may specify), or that each participant’s accumulated payroll deductions will be returned to the participant without interest.

Sub-Plans. Consistent with the requirements of Section 423 of the Internal Revenue Code, the Compensation Committee may amend the terms of the ESPP, or an offering, or provide for separate offerings under the ESPP to, among other things, reflect the impact of local law outside of the United States as applied to one or more eligible employees of a designated subsidiary and may, where appropriate, establish one or more sub-plans to reflect such amended provisions.

Effective Date and Term. If the ESPP is approved by stockholders at the Annual Meeting, the ESPP will become effective on the date of the Annual Meeting. No purchase rights will be granted under the ESPP after the earliest to occur of (i) the day before the 10-year anniversary of the effective date of the plan, (ii) the date on which all shares available for issuance under the ESPP have been issued or (iii) the termination of the ESPP by the Company.

Corporate Transactions. In the event of a consolidation, merger or similar transaction, a sale or transfer of all or substantially all of the Company’s assets, or a dissolution or liquidation of the Company, the Compensation Committee may, in its discretion, provide that each outstanding purchase right will be assumed or substituted for a right granted by the acquiror or successor corporation or by a parent or subsidiary of such entity, or will be cancelled with accumulated payroll deductions returned to each participant, or that the offering period will end before the date of the proposed sale, merger or similar transaction.

New Plan Benefits. Benefits and purchases of shares of our common stock under the ESPP depend on elections made by employees and the fair market value of our common stock on dates in the future. As a result, it is not possible to determine the benefits that will be received by executive officers and other employees in the future under the ESPP. As described above, no employee may purchase shares under the ESPP at a rate that exceeds $25,000 in fair market value in any calendar year.

U.S. Federal Income Tax Consequences Relating to the ESPP

The following is a summary of certain material federal income tax consequences associated with the grant and exercise of purchase rights under the ESPP under current federal tax laws and certain other tax considerations associated with purchase rights under the ESPP. The summary does not address tax rates or non-U.S., state or local tax consequences, nor does it address employment tax or other federal tax consequences except as noted.

The ESPP is intended to qualify as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code. In general, an employee will not recognize U.S. taxable income until the sale or other disposition of the shares of our common stock purchased under the ESPP (ESPP Shares). Upon such sale or disposition, the

employee will generally be subject to tax in an amount that depends on the employee’s holding period with respect to the ESPP Shares.

We are not entitled to a deduction for amounts taxed as ordinary income or capital gain to an employee except to the extent of ordinary income recognized upon a sale or disposition of ESPP Shares prior to the expiration of the holding periods described above.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE APPROVAL OF OUR 2015 EMPLOYEE STOCK PURCHASE PLAN.

At the Annual Meeting, stockholders will be asked to approve an amendment to our 2006 Non-Employee Directors Equity Plan (Directors Plan) to extend the term of the plan. Only our non-employee directors may participate in this plan.

We believe that the ability to grant stock awards to our non-employee directors is critical to our efforts to attract and retain key talent on our Board of Directors and to encourage ownership of shares of our common stock by our non-employee directors. We currently grant stock awards to our non-employee directors under our Directors Plan, which originally was adopted by our Board of Directors on April 5, 2006 and approved by stockholders on May 25, 2006. Stockholders subsequently approved an amendment to the Directors Plan to increase the maximum number of shares of our common stock authorized for issuance under the plan by an additional 750,000 shares, from 850,000 to 1,600,000 shares on June 9, 2010.

The Directors Plan expires by its terms on May 25, 2016 and no further awards may be made under the plan after that date. Accordingly, on March 27, 2015 our Board of Directors amended the Directors Plan to extend the term of the plan for an additional ten years from the date of the Annual Meeting, subject to obtaining stockholder approval of the amendment at this Annual Meeting.

We are not asking stockholders to approve an increase to the number of shares of our common stock that may be issued under the Directors Plan. As of April 10, 2015, 745,250 shares of our common stock remained available for issuance under the Directors Plan. For information about options and restricted stock units outstanding under our existing equity plans, including the Directors Plan, and the number of shares available for issuance under these plans, each, as of December 31, 2014, please see “Equity Compensation Plan Information” elsewhere in this Proxy Statement.

The full text of the Directors Plan, as amended to date and as proposed to be amended, is set forth in Appendix B. The following description of certain features of the Directors Plan, as proposed to be amended, is qualified in its entirety by reference to the full text of the Directors Plan.

Summary of the Directors Plan

Administration and Awards. The Directors Plan is administered by the Compensation Committee, which has

the authority to exercise all powers and authorities granted to it under the plan, including the authority to grant awards; to determine the type and number of awards to be granted, the number of shares of our common stock underlying an award and the terms, conditions and restrictions relating to any award; to determine whether, to what extent and under what circumstances an award may be settled, cancelled, forfeited, exchanged or surrendered; to construe and interpret the plan and any award; to prescribe, amend and rescind rules and regulations relating to the plan; to determine the terms and provisions of award agreements; and to make all other determinations deemed necessary or advisable for the administration of the plan. The Compensation Committee may also waive or amend the operation of plan provisions related to the exercise of awards after a participant’s service on our Board of Directors terminates and, except as otherwise provided in the plan, accelerate or adjust the date on which any award becomes exercisable or vested, so long as the Compensation Committee determines that such acceleration, waiver or adjustment is necessary or desirable.

The Compensation Committee may grant stock options, stock appreciation rights, restricted stock units and other equity-based awards, including dividend equivalent rights, under the Directors Plan, subject to the limitations described below.

Eligibility. All non-employee directors of Biogen who are independent under applicable NASDAQ rules are eligible to participate in the Directors Plan. As of April 10, 2015, 10 non-employee directors were eligible to participate in the Directors Plan.

Shares Subject to the Plan; Share Counting. Subject to adjustment as described in the plan, the maximum aggregate number of shares of our common stock reserved for issuance under the Directors Plan is 1,600,000 shares. Each share underlying an award other than a stock option or a stock appreciation right reduces the number of shares of our common stock available for issuance under the Directors Plan by 1.5 shares, and each share underlying a stock option or a stock appreciation right reduces the number of available shares under the Directors Plan by one share (even if fewer shares are actually issued upon exercise of the stock appreciation right). Shares subject to an award that remain unissued upon the cancellation, surrender, exchange or termination of the award generally may again become available for issuance under the Directors Plan in an amount calculated in accordance with the share counting formula described in the preceding sentence. In the event of a dividend or other distribution or any recapitalization, reclassification, reorganization, merger, share exchange or other similar corporate transaction or event, unless otherwise determined by the Compensation Committee with respect to certain distributions, the number and kind of shares of stock that may be issued in connection with awards, the number and kind of shares of stock or other property issuable in connection with outstanding awards, the exercise price or purchase price relating to outstanding awards and the limits on awards under the Directors Plan will be equitably adjusted. On April 10, 2015, the closing price of our common stock as reflected on the NASDAQ Global Select Market was $425.65.

Types of Awards

Transferability. Awards under the Directors Plan may not be transferred other than by will or the laws of descent and distribution, pursuant to a qualified domestic relations order, or as otherwise determined by the Compensation Committee in its discretion. Awards may be exercisable during a non-employee director’s lifetime only by the director (or by his or her legal representative).

Corporate Transactions; Change in Control. In the event of certain mergers or consolidations of the Company, the liquidation or dissolution of the Company or the sale or disposition of all or substantially all of the Company’s assets, the Compensation Committee will provide for either the assumption or substitution of awards by the successor corporation or its parent, the acceleration of the vesting or exercisability of awards or, following the acceleration of the vesting or exercisability of awards, provide for the cash-out of awards or, upon notice to participants, for the termination of stock options and stock appreciation rights to the extent not exercised by a specified date. Unless otherwise determined by the Compensation Committee, in the event of a change in control of the Company, all awards will become fully vested.

Amendment and Termination. The Board of Directors may amend, suspend, modify or terminate the Directors Plan at any time, subject to stockholder approval to the extent such approval is appropriate or required by the NASDAQ rules or other applicable law. No amendment or termination of the Directors Plan may reduce a non-employee director’s rights under any outstanding award without the consent of the affected director.

Term. If approved by stockholders, the term of the Directors Plan will be extended for an additional ten years from the date of the Annual Meeting and no award may be granted under the Directors Plan after June 10, 2025.

New Plan Benefits. Our Board of Directors has not granted any awards under the Directors Plan subject to stockholder approval of this Proposal 5. Subject to the limitations set

forth in the plan, the Compensation Committee has full discretion to determine the number of shares subject to awards to be granted under the Directors Plan. As a result, future benefits or amounts that would be received under the Directors Plan are not determinable at this time. For information regarding equity awards granted to our non-employee directors during our most recently completed fiscal year please see “Director Compensation” elsewhere in this Proxy Statement.

Other Information. If stockholders do not approve this Proposal 5, the Directors Plan will continue in accordance with its terms and no awards may be granted under the Directors Plan after May 25, 2016.

U.S. Federal Income Tax Consequences Relating to the Directors Plan

The following is a summary of certain material federal income tax consequences with respect to awards that may be granted under to the Directors Plan under current federal tax laws and certain other tax considerations associated with awards under the Directors Plan. The summary does not address tax rates or non-U.S., state or local tax consequences, nor does it address employment tax or other federal tax consequences except as noted.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE APPROVAL OF AN AMENDMENT TO OUR 2006 NON-EMPLOYEE DIRECTORS EQUITY PLAN.

Section 16(a) Beneficial Ownership Reporting Compliance

Section 16(a) of the Securities Exchange Act requires our executive officers, directors and greater than 10% stockholders to file initial reports of ownership and changes of ownership of our common stock. As a practical matter, we assist our directors and executive officers by monitoring transactions and completing and filing Section 16 forms on their behalf. Based solely on information provided to us by our directors and executive officers, we believe that during 2014 all such parties complied with all applicable filing requirements.

Corporate Governance Highlights

We strive to maintain effective corporate governance practices to ensure that our company is managed for the long-term benefit of our stockholders.

We review our corporate governance principles and practices on a regular basis. Since our last annual meeting of stockholders in 2014, we placed significant focus on our board committees and rights of our stockholders, and have enacted the following changes:

In addition to our recent board committee changes and implementation of proxy access, we believe that our overall governance features include a number of practices and policies that are favorable to our Company and stockholders, including the following:

Director Independence

Board of Directors. All of our directors and nominees for director, other than Dr. Scangos, our Chief Executive Officer, satisfy the independence requirements of NASDAQ. In determining that Dr. Papadopoulos is independent, our Board of Directors considered that Dr. Papadopoulos is a director or advisor to certain companies with which we collaborate.

Committees. The committees of our Board of Directors consist solely of independent directors, as defined by NASDAQ rules. The members of the Audit Committee also meet the additional SEC and NASDAQ independence and experience requirements applicable specifically to audit committee members. In addition, all of the members of the Compensation Committee are non-employee directors within the meaning of the rules under Section 16 of the Securities Exchange Act and outside directors for purposes of Section 162(m) of the Internal Revenue Code, and the Board of Directors has affirmatively determined that the members of our Compensation Committee satisfy the additional independence requirements specifically applicable to compensation committee members.

Leadership Structure. We currently separate the roles of Chairman of the Board of Directors and Chief Executive Officer. Stelios Papadopoulos, an independent director, is

Chairman of the Board and has served as such since June 2014. Among other responsibilities, our Chairman:

We believe that having an independent Chairman promotes a greater role for the independent directors in the oversight of the Company, including oversight of material risks facing the Company, encourages active participation by the independent directors in the work of our Board of Directors, enhances our Board of Directors’ role of representing stockholders’ interests, and improves our Board of Directors’ ability to supervise and evaluate our Chief Executive Officer and other executive officers.

Nominating Processes

The Corporate Governance Committee is responsible for identifying individuals qualified to become members of our Board of Directors and reviewing candidates recommended by stockholders. Stockholders may recommend nominees for consideration by the Corporate Governance Committee by submitting the names and supporting information to the Secretary, Biogen Inc., 225 Binney Street, Cambridge, Massachusetts 02142. Any such recommendation should include at a minimum the name(s) and address(es) of the stockholder(s) making the recommendation and appropriate biographical information for the proposed nominee(s). Candidates who are recommended by stockholders will be considered in the same manner as candidates from other sources. For all potential candidates, the Corporate Governance Committee will consider all factors it deems relevant, including at a minimum those listed below in the subsection

titled “Director Qualification Standards and Diversity.” Director nominations are recommended by the Corporate Governance Committee to our Board of Directors and must be approved by a majority of independent directors.

In addition, our Bylaws contain provisions that address the process by which a stockholder may nominate an individual to stand for election to our Board of Directors at an annual meeting of stockholders.

Information required by our Bylaws to be in the notice includes, among other things, the name, contact information and security ownership information for the candidate and the person making the nomination, any voting commitment by the candidate, whether the person making the nomination is part of a group that intends to deliver a proxy statement or solicit proxies, and other information about the proposed nominee that must be disclosed in proxy solicitations under Section 14 of the Securities Exchange Act and the related rules and regulations under that Section. The Corporate Governance Committee may also require any proposed nominee to furnish such other information as may be reasonably required to determine the eligibility of such proposed nominee to serve on our Board of Directors.

Annual Elections and Majority Voting

Our directors are elected annually to serve until the next annual meeting of stockholders and until their successors are duly elected and qualified. Our directors must be elected by a majority of votes cast in uncontested elections (meaning any election for which the number of directors nominated does not exceed the number of directors to be elected at such meeting), and by a plurality of votes cast in contested elections (meaning any election for which the number of directors nominated exceeds the number of directors to be elected at such meeting, regardless of whether such nominees were proposed by the Company or by stockholders). In addition, following their appointment or election by stockholders to our Board of Directors, directors must submit an irrevocable resignation that will be effective upon (1) the failure to receive the required number of votes for reelection at the next annual meeting of stockholders at which they face reelection and (2) acceptance of such resignation by our Board of Directors. If an incumbent director fails to receive the number of votes required for reelection, our Board of Directors (excluding the director in question) will, within 90 days after certification of the election results, decide whether to accept the director’s resignation taking into account such factors as it deems relevant. Such factors may include the stated reasons why stockholders voted against such director’s reelection, the qualifications of the director and whether

accepting the resignation would cause us to fail to meet any applicable listing standards or would violate state law. Our Board of Directors will promptly disclose its decision in a filing with the SEC.

Director Qualification Standards and Diversity

Our Corporate Governance Principles provide that directors should possess the highest personal and professional ethics and integrity, understand and be aligned with our core values, and be committed to representing the long-term interests of our stockholders. Our directors must also be inquisitive and objective and have practical wisdom and mature judgment. In accordance with our Corporate Governance Principles, we endeavor to have a Board of Directors that collectively represents diverse experience at strategic and policy-making levels in business, government, education, healthcare, science and technology, and the international arena, and collectively has knowledge and expertise in the functional areas of accounting and finance, risk management and compliance, strategic and business planning, corporate governance, human resources, marketing and commercial, and research and development. Consistent with our Corporate Governance Principles, in selecting nominees to our Board of Directors, the Corporate Governance Committee considers the diversity of skills and experience that a potential nominee possesses and the extent to which such diversity would enhance the perspective, background, knowledge and experience of our Board of Directors as a whole. The Board of Directors considers personal diversity, including gender, ethnic and racial diversity, as an additional benefit to the Board of Directors as a whole.

Our directors must be willing to devote sufficient time to carrying out their duties and responsibilities effectively. We

ask directors not to serve on more than six boards of public companies including ours. In addition, our Chief Executive Officer may not serve on more than two boards of directors of public companies in addition to ours.

Our Board of Directors does not believe that arbitrary term limits on directors’ service are appropriate, nor does it believe that directors should expect to be re-nominated. Regular evaluations are an important determinant for continued tenure, and, to that end, our Board of Directors and its committees perform a self-evaluation on a regular basis and as may be required by applicable laws, rules and regulations. Our Corporate Governance Principles provide that directors should offer their resignation in the event of any significant change in personal circumstances, including a significant change in principal job responsibilities or any circumstances that may adversely affect their ability to effectively carry out their duties and responsibilities or in the case of a significant conflict of interest that cannot otherwise be resolved. Our directors are also expected, but not required, to offer their resignation to our Board of Directors effective at the annual meeting of stockholders in the year of their 75^th birthday.

Our Board of Directors met 10 times in 2014. No current director attended fewer than 75% of the total number of meetings of our Board of Directors and the committees on which he or she served during 2014. Under our Corporate Governance Principles, our independent directors are required to meet without management present at least four times each year. Independent directors may also meet without management present at such other times as determined by our Chairman, or if requested by at least two other directors. In 2014, our independent directors met without management present four times. In addition, we expect all of our directors and director nominees to attend our annual meetings of stockholders. All of our directors attended our 2014 annual meeting of stockholders.

Risk Oversight

Our Board of Directors provides oversight of material risks facing the Company. Our Board of Directors regularly receives information about our material strategic, operational, financial and compliance risks and management’s

response to, and mitigation of, such risks. In addition, our risk management systems, including our risk assessment processes, internal controls over financial reporting, compliance programs and internal and external auditing procedures are designed, in part, to inform management and our Board of Directors about our material risks. As part of its risk oversight function, our Board of Directors and its committees review this framework, its operation and our strategies for generating long-term value for our stockholders to ensure that such strategies will not motivate management to take excessive risks.

In determining the allocation of risk oversight responsibilities, our Board of Directors and its committees generally oversee material risks within their identified area of concern. The Board and each committee meet regularly with management to ensure that management has identified relevant risks and is adequately assessing, monitoring, and taking appropriate action to mitigate risk. A summary of the key areas of risk oversight responsibility of the Board and each of its committees is set forth below:

Compensation Risk Assessment

The Compensation Discussion and Analysis (CD&A) section of this Proxy Statement describes our compensation policies, programs and practices for our executive officers. Our goal-setting, performance assessment and compensation decision-making processes described in the CD&A apply to all employees. Our long-term incentive program provides different forms of awards depending upon an employee’s level, but is otherwise consistent throughout the Company. We offer a limited number of cash incentive plans, with employees eligible for either our annual cash incentive plan or a sales incentive compensation plan; no employee is eligible to participate in more than one cash incentive plan at any time. Our annual cash incentive plan is consistent for all participants globally, with the same Company performance goals, payout curves and administrative provisions regardless of the participant’s job level, location or function in the Company. In the CD&A, we describe the risk-mitigation controls for our compensation programs, including the role of our Compensation Committee to review and approve the design, goals and payouts under our annual cash incentive plan and long-term incentive program as well as approving each executive officer’s compensation. In addition, we have reviewed the processes, controls and design of our sales incentive compensation plans. Based on our assessment, we believe that our compensation policies, programs and practices do not create risks that are reasonably likely to have a material adverse effect on the Company.

Audit Committee Report

The Audit Committee’s role is to act on behalf of our Board of Directors in the oversight of all aspects of Biogen’s financial reporting, internal control and audit functions. The roles and responsibilities of the Audit Committee are set forth in the written charter adopted by our Board of Directors, which is posted on our website, www.biogen.com, under the “Corporate Governance” subsection of the “Investors” section of the site. Management has primary responsibility for the financial statements and the reporting process, including the systems of internal controls.

In fulfilling its oversight responsibilities, the Audit Committee reviewed and discussed with management the audited consolidated financial statements contained in Biogen’s 2014 Annual Report on Form 10-K. The Audit Committee discussed with PricewaterhouseCoopers LLP, Biogen’s independent registered public accounting firm, the overall scope and plans for the audit. The Audit Committee met with PricewaterhouseCoopers, with and without management present, to discuss the results of its examination,

management’s response to any significant findings, its observations of Biogen’s internal controls, the overall quality of Biogen’s financial reporting, the selection, application and disclosure of critical accounting policies, new accounting developments and accounting-related disclosure, the key accounting judgments and assumptions made in preparing the financial statements and whether the financial statements would have materially changed had different judgments and assumptions been made, and other pertinent items related to Biogen’s accounting, internal controls and financial reporting. The Audit Committee also discussed with representatives of Biogen’s corporate internal audit staff their purpose and authority and their audit plan.

The Audit Committee also reviewed and discussed with PricewaterhouseCoopers the matters required to be discussed with the Audit Committee under generally accepted auditing standards (including Public Company Accounting Oversight Board — Auditing Standard No. 16). In addition, the Audit Committee discussed with PricewaterhouseCoopers the independence of PricewaterhouseCoopers from management and Biogen, including the written disclosures and letter concerning independence received from PricewaterhouseCoopers required by applicable requirements of the Public Company Accounting Oversight Board. The Audit Committee has determined that the provision of non-audit services to Biogen by PricewaterhouseCoopers is compatible with its independence.

During 2014, the Audit Committee provided oversight and advice to management in connection with Biogen’s system of internal control over financial reporting in response to the requirements set forth in Section 404 of the Sarbanes-Oxley Act of 2002 and related regulations. In connection with this oversight, the Audit Committee reviewed a report by management on the effectiveness of Biogen’s internal control over financial reporting. The Audit Committee also reviewed PricewaterhouseCoopers’ Report of Independent Registered Public Accounting Firm included in Biogen’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014 related to its audit of the effectiveness of internal control over financial reporting.

In reliance on these reviews and discussions, the Audit Committee recommended to our Board of Directors that the audited consolidated financial statements be included in Biogen’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014 for filing with the SEC.

The Audit Committee of our Board of Directors:

Caroline D. Dorsa (Chair)

Nancy L. Leaming

Stelios Papadopoulos

Brian S. Posner

COMPENSATION DISCUSSION AND ANALYSIS

This Compensation Discussion and Analysis (CD&A) describes the compensation strategy, philosophy, policies, and practices underlying our executive compensation program for 2014. It also provides information regarding the manner and context in which compensation was earned by and awarded to our 2014 named executive officers listed below, whom we refer to collectively as “Named Executive Officers” or “NEOs”.

		George Scangos, Ph.D. Chief Executive Officer
		Paul Clancy, M.B.A. Executive Vice President, Chief Financial Officer
		Adriana Karaboutis, M.S. Executive Vice President, Technology & Business Solutions
		Alfred Sandrock, M.D., Ph.D. Group Senior Vice President, Chief Medical Officer
		Adam Koppel, M.B.A., M.D., Ph.D. Senior Vice President, Chief Strategy Officer

Executive Summary

2014 Highlights

2014 was a very good year for Biogen and the patients we serve, as we reached or exceeded many of our financial, operational and strategic goals. We successfully launched four products in two distinct therapeutic markets, advanced several potential therapeutic options across a broad set of disease areas, enhanced our pipeline through strategic transactions and collaborations, strengthened our research and development and leadership teams, and continued our leadership in a number of social and environmental initiatives.

Stockholder Alignment - Total Shareholder Return

Our stock price increased from $279.57 to $339.45 per share during 2014, reflecting strong stock price appreciation and a one-year total shareholder return (TSR) of 21%. This compares to our peer group median one-year TSR of 31% and the Standard & Poor’s 500 (S&P 500) one-year TSR of 15%. Our three-year TSR is 46% compared with our peer group median three-year TSR of 38% and the three-year S&P 500 TSR of 22%. Our peer group is described below under “External Market Competitiveness and Peer Group”.

Financial Performance

Significant financial growth was achieved in 2014 when compared to another year of strong performance in 2013, as demonstrated by our increase in revenues, net income and diluted earnings per share (EPS), as shown below.

A reconciliation of our GAAP to non-GAAP financial measures is provided in Appendix C to this Proxy Statement.

Product and Pipeline Developments

We solidified our leadership position in multiple sclerosis (MS), expanded our portfolio of therapies for patients and strengthened our research and development organization as described below.

2014 also marked an important milestone for our company as we launched treatments for hemophilia following the US approvals of ALPROLIX^® for hemophilia B and ELOCTATE^® for hemophilia A. These longer-acting therapies represent the first meaningful innovation in the treatment of hemophilia in many years. In furtherance of our commitment to the hemophilia community, we and our collaborator, Swedish Orphan Biovitrum AB, announced plans to donate up to one billion international units of ALPROLIX and ELOCTATE for humanitarian aid programs in the developing world. This reflects our mission to help provide underserved patients with access to our therapies.

We also advanced a number of programs in our pipeline and remained focused on bringing forward the next-generation of potential treatments.

We also increased the number of promising assets in our pipeline through strategic acquisitions and collaborations, including our agreement with Sangamo BioSciences to develop and commercialize product candidates using gene editing technologies for the treatment of two inherited blood disorders, sickle cell disease and beta-thalassemia, and our agreement with Eisai Co., Ltd. to jointly develop and commercialize two Eisai product candidates in Alzheimer’s Disease.

Through our biosimilar joint venture, Samsung Bioepis, we made important progress toward our objective of becoming active in the development of biosimilar pharmaceuticals. Samsung Bioepis’ marketing authorization application for a biosimilar version of Enbrel^® (etanercept) was recently accepted for review by the European Medicines Agency. It

is our belief that biosimilars will become increasingly important in the role of healthcare and we believe we are well positioned to contribute to this evolution.

Finally, during the year, we strengthened our research and development organization through the hiring of leading researchers to join our internal research team.

Leadership Team

At the core of what we do are our people and our leaders. As a result, our goal is to find top-tier talent with the skills necessary to imagine and lead us into the future. We advanced this goal in 2014 with the addition of two key members to our leadership team.

In determining the compensation of Ms. Karaboutis and Dr. Koppel, the Compensation Committee followed the same compensation philosophy and objectives described below and also took into consideration the value of compensation forfeited at their prior employment when determining their compensation and one-time sign-on awards. Each of Ms. Karaboutis and Dr. Koppel are Named Executive Officers in 2014, due primarily to the sign-on awards granted to each of them in connection with their hire.

Other Achievements

In 2014, we received a number of accolades for our workplace and community efforts and involvement, including the following:

The Compensation Committee considered the foregoing achievements when it reviewed and assessed each of the pay-for-performance compensation elements for each of the Named Executive Officers in 2014.

2014 Executive Compensation Programs

We believe our executive compensation programs are effectively designed and have worked well to implement a pay-for-performance culture that is aligned with the interests of our stockholders.

In 2014, our executive compensation programs consisted of base salary, short- and long-term incentives and other benefits. Approximately 81% of our compensation programs were performance-based and pay-at-risk for our NEOs

(other than Ms. Karaboutis and Dr. Koppel, who were not employed by us for the full year):

In 2013, we undertook a comprehensive review of our total rewards offerings to ensure that they were optimized not only in the dollars invested but also in the perceived value of the programs by all our employees including the NEOs. Our review indicated that the investment we make in our overall compensation programs correlates well with the perceived value of these programs by our employees.

In 2014, we made the following modest changes to our executive compensation programs to further align our programs with our peer group and general market practices, and to simplify our incentives to make it easier for our executives to stay focused on achieving our short- and long-term Company goals.

Other key decisions in recognition of the Company’s strong achievements against the 2014 pre-established performance goals can be found below under the heading “2014 Performance-Based Plans.”

2014 Advisory Vote on Executive Compensation

At our 2014 annual meeting of stockholders, 97% of the votes cast were in favor of the compensation of our Named Executive Officers in our annual “Say on Pay” proposal. The Compensation Committee viewed this as very positive support for our executive compensation programs and their alignment with long-term stockholder value creation and took note that the Company’s executive compensation programs have been effective in implementing the Company’s stated compensation philosophy and objectives.

Our Compensation Committee is committed to continually reviewing our executive compensation programs on a proactive basis to ensure the ongoing alignment of our Company and stockholders as discussed above.

Roles & Responsibilities

Role of the Compensation Committee

The Compensation Committee oversees and administers our executive compensation programs. The roles and responsibilities of the Compensation Committee are set forth in its written charter adopted by our Board of Directors, which can be found on our website, www.biogen.com, under the “Corporate Governance” subsection of the “Investors” section of the site.

Role of the Independent Compensation Consultant

The Compensation Committee believes that independent advice is important in developing Biogen’s executive compensation programs. Frederic W. Cook & Co., Inc. (FWC) is currently engaged as the Compensation Committee’s independent compensation consultant. FWC does not provide any other services to Biogen.

Reporting directly to the Compensation Committee, FWC provides guidance on trends in CEO, executive and non-employee director compensation, the development of specific executive compensation programs, and the composition of the Company’s compensation peer group. Additionally, FWC prepares a report on CEO pay that compares each element of

compensation to chief executive officers in comparable positions at companies in our peer group. Using this and other similar information, the Compensation Committee recommends, and our Board of Directors approves, the elements and target levels of our CEO’s compensation. FWC also engages in other matters as needed and as directed solely by the Compensation Committee.

During 2014, the Company paid FWC approximately $196,490 in consulting fees directly related to these services. The Compensation Committee assesses FWC’s independence annually and, in accordance with applicable SEC and NASDAQ rules, confirmed in December 2014 that FWC’s work did not raise any conflict of interest and that FWC remains independent under applicable rules.

Role of our CEO

Each year, our CEO provides an assessment of each executive officer’s performance during the prior year and recommends to the Compensation Committee the compensation to be awarded to each executive officer other than for himself. The recommended compensation is based on numerous factors including: Company, team and individual performance; potential for future contributions; leadership behaviors; external market competitiveness; internal pay comparisons; and other factors deemed relevant.

To understand external market competitiveness of the compensation for our executive officers, our CEO and the Compensation Committee review a report analyzing publicly available information and surveys prepared by our internal compensation group and reviewed by FWC. The report compares the compensation of each executive officer, other than our CEO, relative to data for comparable positions at companies in our peer group, by compensation element (see “External Market Competitiveness and Peer Group” below for further details). The Compensation Committee considers all of the information presented, discusses the recommendations with our CEO and with FWC, and applies its judgment to determine the elements of compensation and target compensation levels for each executive officer.

Our CEO also provides a self-assessment of his achievements for the prior year. The Compensation Committee reviews and considers this in determining the CEO’s performance and in recommending for approval by the Board of Directors the compensation of our CEO. Our CEO does not participate in the deliberations regarding his own compensation.

Executive Compensation Philosophy and Objectives

Our executive compensation programs are designed to drive the creation of long-term stockholder value by delivering performance-based compensation that is competitive with our peer group in order to attract and retain extraordinary leaders who can perform effectively and succeed in a demanding business environment. We achieve this by designing programs that are:

External Market Competitiveness and Peer Group

Market practices are one of our considerations when determining the executive compensation levels and program designs at Biogen. While we review external market practices to ensure that we provide programs designed to attract, retain and inspire extraordinary talent, we do not target a specific market percentile or simply replicate the market practice. Instead, we strive to provide meaningful rewards that are tied to our mission of delivering innovative therapies to our patients so that our leaders are inspired and rewarded appropriately for their achievements.

Each year our compensation consultant reviews the external market landscape and evaluates the composition of our peer group for appropriateness. Our peer group is primarily composed of biotechnology and pharmaceutical companies, as we compete with companies in both of these sectors for executive talent. Also included is a life sciences tools and services company, Life Technologies, as it meets our size criteria, is in a similar industry code, and has been selected by proxy advisory firms as a comparator. The companies included in the peer group used in connection with our compensation decisions in February 2014 were the following:

The Compensation Committee selects our peer group based on comparable companies that approximate (1) our scope of business, including revenue and market capitalization, (2) our global geographical reach, (3) our research-based business with multiple marketed products, and (4) a comparable pool of talent for which we compete.

As of March 2013, at the time the Compensation Committee reviewed and set Biogen’s peer group that was used as a reference when making compensation decisions in February 2014, Biogen compared to its peer group in the following financial metrics as follows:

Data Source: Standard & Poor’s Research Insight

In March 2014, after compensation decisions for the prior year were determined, the Compensation Committee conducted a comprehensive review of our peer group and determined that AbbVie would be added to the peer group going forward due to the consolidation of companies in the peer group due to then pending acquisitions of Life Technologies and Forest Laboratories.

For each of the companies in our peer group, we analyze the company’s Compensation Discussion and Analysis and other data publicly filed during the prior year to identify the executives at such companies whose positions are comparable to those held by our executive officers. We then compile and analyze the data for each comparable position. Our competitive analysis includes the structure and design of the compensation programs as well as the targeted value of the compensation.

For our NEOs other than our Chief Executive Officer, we also use compensation surveys to assess competitive

practices and levels of compensation as the data available in publicly available filings of companies in our peer group addresses only a limited number of our executive positions. For 2014, consistent with past years, we used the Towers Watson U.S. CDB Pharmaceutical Executive Compensation Database survey (Towers Watson). We chose this survey because of the number of companies in our peer group that participate in it, the number of positions reported by the survey which continue to be comparable to our executive positions, and the high standards under which we understand the survey is conducted (including data collection and analysis methodologies). All of the companies in our peer group are represented in a special cross-section of the survey focused on our peer group, other than Life Technologies due to its 2014 acquisition by Thermo Fisher Scientific.

Compensation Elements

The Compensation Committee determines the elements of compensation we provide to our executive officers. The elements of our executive compensation programs and their objectives are as follows:

Compensation Pay Mix

The Compensation Committee determines the general mix of the elements of our executive compensation programs. It does not target a specific mix of value for our compensation elements in either the program design or pay decisions. Rather, the Compensation Committee reviews the pay mix to ensure an appropriate level of performance-based compensation is apportioned to the short-term and even more to the long-term to ensure alignment with our business goals and performance.

Additionally, the Compensation Committee believes the greater the leadership responsibilities, the greater the impact an individual will have on Biogen’s future strategic direction. Therefore, for our executive officers, additional emphasis is placed on performance-based compensation, with a particular emphasis on long-term incentives.

The 2014 pay mix for our CEO and our other Named Executive Officers is set forth below: