UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE

SECURITIES EXCHANGE ACT OF 1934

Filed by the Registrant    ☒                Filed by a Party other than the Registrant  ☐

Check the appropriate box:

BIOGEN INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

20192020 Annual Meeting of

Stockholders and Proxy Statement

        Wednesday, June 19, 20193, 2020

        9:00 a.m. Eastern Time

        To be held online at our offices located at 225 Binney Street,

        Cambridge, Massachusetts 02142 and

        online atwww.virtualshareholdermeeting.com/BIIB2019BIIB2020

April 30, 201920, 2020

To My Fellow Stockholders:

On behalf of the Board of Directors, I want to thank you for your investment in Biogen and for the confidence you putplace in this Board to oversee your interests in our company. For more than 40 years, Biogen has played a key role in advancing the field of biotechnology as we work to solve some of the most challenging and complex diseases. Today, as we collectively face the challenges posed by the globalCOVID-19 pandemic, the importance of developing and assuring access to therapies for patients in need is more evident than ever.

Our view is that neurological diseases are deeply connected and becauseIn response to the pathways of these diseases are interrelated, so are the potential approaches for treating them. While we made progress in a numberCOVID-19 pandemic, which has directly affected many of our corecommunities and emerging growth areas in 2018, we also know it is the naturesome of drug development that many studies fail before one succeeds. In March 2019, togetherour employees, and consistent with our collaboration partner Eisai Co. Ltd., we decided to discontinue the global Phase 3 aducanumab studies ENGAGE and EMERGE based on analysis performed by an independent data monitoring committee that concluded that aducanumab was unlikely to meet the pre-determined efficacy targets. While a decision to discontinue a program is always disappointing, most importantly for patients who need effective treatments, we remain focused on the learnings and priorities that we take away from every clinical study.

Our philosophy of Caring Deeply. Working Fearlessly. Changing Lives.^™ informs, we have taken a number of actions to support our employees and their families, our stakeholders and society at large. These actions include implementing policies and practices to safeguard our employees and communities and reduce the spread of the virus, as well as supporting global relief and research efforts to help detect, treat and eradicate the virus. At the same time, we have remained committed to operating our business practices. to serve the needs of our patients and advance our mission of being pioneers in neuroscience.

We workentered 2020 following a remarkable year for Biogen. In 2019 we performed well across all of our core business areas, strengthened our pipeline and continued to haveexecute on our strategy. All while remaining focused on our goal of advancing pioneering science for the patients we serve, our communities, our employees and you, our fellow stockholders. We believe we are well positioned to continue developing transformational therapies for neurological diseases, an impact beyondarea with high disease prevalence and significant unmet need.

When I wrote to you last year, it was shortly after the announcement of the discontinuation of our medicinesglobal Phase 3 studies of aducanumab, the investigational treatment for early Alzheimer’s disease we are developing in collaboration with Eisai Co., Ltd. In the months following the discontinuation of these studies, we followed the science, as we strive to improve patient health outcomes, solve socialalways do, and environmental challenges, cultivate a workplace that enables our employees to thrive, support local communities and inspire future generations of scientists.

2018 marked our 40^th anniversary, a remarkable milestone honoring our legacy as oneanalysis of the oldest independent biotechnology companies. Looking back,larger dataset available from these studies showed that sufficient exposure to high dose aducanumab reduced clinical decline across multiple endpoints. We continue to actively engage with the U.S. Food and Drug Administration, as well as regulators in Europe and Japan, to pursue potential regulatory approval for aducanumab. If approved, aducanumab would become the first therapy to reduce clinical decline in Alzheimer’s disease.

The events of this past year serve as an important reminder that the path taken in the pursuit of discovering and developing breakthrough treatments is not always direct and straight forward. It is also a reminder of the importance of our commitment to following the science and doing the right thing for patients.

We also have a great sense of responsibility about our role as corporate citizens and our impact on society both today and in the future. We care deeply about making a difference and are passionate about our commitment to corporate social responsibility and stewardship, including environmental sustainability, diversity and inclusion, STEM education and other key initiatives. We believe doing the right things for patients, employees, the environment and the communities we have always been pioneers, having the courage to take new approaches toserve will help people who suffer from devastating diseases. Thanks tobuild sustainable value for all our fearless mindset and groundbreaking research, thousands of patients today have access to life-changing treatments.stakeholders, including our stockholders.

Our Board takes its role in protecting the interest of our fellow stockholders and overseeing our long-term business strategy very seriously. We believe that good corporate governance and high ethical standards are key to our success. We are accountable to you, our fellow stockholders, and remain committed to investing time with you to increase transparency and better understand your perspectives. During 20182019 independent members of our Board met with several stockholders to discuss a variety of topics, including business strategy, capital allocation, corporate governance, executive compensation, sustainability and our corporate social responsibility initiatives. We look forward to continuing these dialogues in 2020 and beyond.

Last year, we added two new independent directors to our Board. These new directors, along with our existing directors, bring a range of skills and industry experience to our Board as we advance pioneering science for the betterment of humanity and work to build a multi-franchise neuroscience portfolio. Our Board believes ensuringhaving diverse perspectives, including a mix of skills, experience and backgrounds, areis key to representing the interests of stockholders effectively. This year we have nominated three new candidates to stand for election as directors at our 2019 annual meeting of stockholders.

We are proud of all of our accomplishments in 2018,2019, including:

The following notice of our annual meeting of stockholders contains details of the business to be conducted at the meeting. Only stockholders of record at the close of business on April 22, 2019,6, 2020, will be entitled to notice of, and to vote at, the annual meeting.

OnIt is an honor to serve as your Chairman and, on behalf of the Board of Directors, I thank you for your continued support and investment in Biogen.

Very truly yours,

STELIOS PAPADOPOULOS, Ph.D.

Chairman of the Board

On behalf of the Board of Directors of Biogen Inc.

225 Binney Street

Cambridge, Massachusetts 02142

By Order of Our Board of Directors,

SUSAN H. ALEXANDER,

Secretary

225 Binney Street

Cambridge, Massachusetts 02142

April 30, 201920, 2020

This Notice and Proxy Statement are first being sent to stockholders on or about April 30, 2019.20, 2020.

Our 20182019 Annual Report on Form10-K is being sent with this Notice and Proxy Statement.

This summary highlights important information you will find in this Proxy Statement. As it is only a summary, please review the complete Proxy Statement before you vote.

Vote Right Away Through Advance Voting Methods Vote by Internet Using Your Computer Go to www.proxyvote.com and enter the 16-digit control number provided on your proxy card or voting instruction form. Vote by Telephone Call 800-690-6903 or the number on your proxy card or voting instruction form. You will need the 16-digit control number provided on your proxy card or voting instruction form. Vote by Mail Complete, sign and date the proxy card or voting instruction form and mail it in the accompanying pre-addressed envelope. Vote During Meeting See Part 1 - "General Information About the Meeting" for details on how to vote during the Annual Meeting.

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We are focused on discovering, developing and delivering worldwide innovative therapies for people living with serious neurological and neurodegenerative diseases as well as related therapeutic adjacencies. Our core growth areas include multiple sclerosis (MS) and neuroimmunology,neuroimmunology; Alzheimer’s disease (AD) and dementia, movement disorders, including Parkinson’s disease, anddementia; neuromuscular disorders, including spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS).; movement disorders, including Parkinson’s disease; and ophthalmology. We are also focused on discovering, developing and delivering worldwide innovative therapies in our emerging growth areas of immunology; neurocognitive disorders; acute neurology, neurocognitive disorders, painneurology; and ophthalmology.pain. In addition, we are employing innovative technologies to discover potential treatments for rare and genetic disorders, including new ways of treating diseases through gene therapy in our core and emerging growth areas. We also commercialize biosimilars of advanced biologics. We support our drug discovery and development efforts through the commitment of significant resources to discovery, research and development programs and business development opportunities. For additional information, please see our 20182019 Annual Report on Form10-K.

20182019 Operating Performance Highlights

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Proxy Statement Summary (continued)

Biogen Elements

Much like the periodic table of elements documents the building blocks of the universe around us, theBiogen Elements give shape to our company’s culture and are embedded into all our people processes, including performance management, goal setting and development programs and activities. The Biogen Elements drive the behaviors, actions and decisions required to achieve our strategy and promote a unified approach to our individual jobs – strengthening our mission, informing our leadership, expanding our impact and fueling our growth.

96 Cf CUSTOMER FOCUSED 13 In INCLUSIVE 14 P PIONEERING 71 Ag AGILE 02 A ACCOUNTABLE 11 E ETHICAL

As we remain focused on discovering, developing and delivering worldwide innovative therapies, we remaincustomer focused. We keep patients, payers and physicians front and center in our daily work and collaborate to solve critical scientific and business challenges. In doing so, we foster aninclusivecommunity, both internally and externally. We work in partnership to break down siloes and encourage diverse perspectives and backgrounds at all levels.

Apioneeringspirit permeates our work. We challenge the status quo and experiment to create new possibilities. We are not afraid to take calculated risks and learn from failure. We are resilient andagile, adapting in response to internal changes and external disruptors, and developing solutions quickly to take advantage of emerging opportunities.

As pioneers and leaders, we hold ourselvesaccountable for our work and results. We honor our commitments and we never compromise our integrity. We sustain anethicalenvironment of trust, honesty and transparency while ensuring appropriate confidentiality.

Environmental Sustainability

We are committed to solving environmental challenges. We work to improve our operational impact on the environment and have adopted strong sustainability policies. We aspire to be a catalyst for positive change by addressing environmental impacts resulting from our business, including carbon and water, and by increasing the environmental and social performance of our supply chain.

As part of this commitment, we utilize a science-based approach to reduce our environmental footprint, demonstrated by our Science Based Targets Initiative-approved 2030 absolute greenhouse gas reduction target of 35%. Our practice of using science to inform our targets when possible is part of our broader commitment to context-based sustainability. For example, we achieved our target to assess 100% of our major sites utilizing a context-based water approach by the end of 2019. These sites were determined to be within fair, just and proportional share of the local watersheds’ sustainable water supply. We embrace green chemistry as an opportunity to improve sustainability in our operations, and we work to find new and better ways to minimize waste and maintain zero waste to landfill in our manufacturing facilities.

Our 20182019 accomplishments include:

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Diversity and Inclusion

We believe that diversity in all forms is a key to our success. Different perspectives make us stronger as a business. Our diversity and inclusion strategy touches every facet of our business, focusing on three key components: expanding workforce diversity, improving health outcomes for underserved global patient populations and developing a sustainable, diverse supplier base.

We are honored to be recognized as a company of choice. In 20182019 Biogen was ranked #51#85 on theForbes list of World’s Best Employers as well as oneand #42 on theForbes list of theAmerica’s Best Employers for Women (at #38).Employers. We scored 100% on the 20182019 Disability Equality Index, which measures our policies and practices related to disability inclusion.inclusion, for the third consecutive year. Additionally, for the fifthsixth consecutive year, we were recognized as a Best Place to Work for LGBTQ Equality by the Human Rights Campaign, scoring 100% on their Corporate Equality Index.

Community Engagement

Our employees are not only passionate about how their work at Biogen may help improve lives, they are also engaged across a broad range of activities to improve our company’s work and role in the community, such as our Care Deeply Day. In 2019 alone, over 3,000 employees from over 30 countries volunteered at different service projects in the communities where we live and work during this annual day of service. Many Biogen employees at our manufacturing sites also participate in Communities of Practice (CoP),employee-led groups engaged in activities around a common interest. One such group is ourIMPACT, a CoP focused on furthering our environmental sustainability initiatives at Biogen. This group tackles issues such as reducing waste in the workplace through reuse programs, improving energy use in laboratories and bringing healthier and more climate-friendly meals into Biogen’s cafeterias.

Our Community Lab, with locations at our headquarters in Cambridge, Massachusetts, which opened in 2002, and in Research Triangle Park, North Carolina, which opened in 2014, is the longest-running,hands-on corporate science lab in the nation, serving as the model for a growing number of similar initiatives in the biotech community. At our Community Labs, local middle and high school students can engage inhands-on biotechnology experiments and interact with scientists and other biotech professionals in astate-of-the-art laboratory classroom. It offers free daylong, interactive science activities, rigorous summer programs and teacher professional development. Since its inception, our Community Labs have engaged more than 54,000 students inhands-on learning to inspire their passion for science and, in 2019, 54% of our summer Community Lab students were from underrepresented and/orlow-income household groups.

In 2019 we opened anon-profit kitchen with Food for Free in our corporate headquarters in Cambridge, Massachusetts to give back to those in our neighborhood. Food for Free, a Cambridgenon-profit whose mission is to fight food insecurity, collects leftover and donated food that otherwise would go to waste and gets it to people in need in 15 communities in our area. As of March 31, 2020, we have produced almost 20,000 meals in the Biogen Family Meals kitchen that have been distributed to over 25 different agencies and schools in the Greater Boston area, including sevenK-12 schools and four community colleges.

The Biogen Foundation

The Biogen Foundation supports access to science education and to essential human services for children and their families in the communities in which we work and live. The Biogen Foundation is deeply committed to sparking a passion for science and discovery, supporting effective science education initiatives and strengthening efforts to make science education and science careers accessible to diverse populations. Most of all, we want young people to know that through science they have the ability to change the world.

The Biogen Foundation’s grant-making programs focus on two core areas: science education and strengthening our communities. As a result, the Biogen Foundation is committed to supporting nonprofit organizations that focus on four areas: providing access tohands-on science education, teacher development in science, college readiness and support and basic social needs (child hunger, poverty and social mobility). In 2019 the Biogen Foundation’s grant program donated $4.6 million to worthy organizations ranging from food banks and community services organizations to science education and teacher development programs.

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The Biogen Foundation also matches Biogen employee gifts to nonprofit organizations, up to $25,000 per employee, per year. In 2019 the matching grant program contributed $1.66 million to worthy organizations ranging from disease organizations and camps for children with serious illnesses to disaster relief efforts.

In March 2020 the Biogen Foundation committed $10 million to support global response efforts and communities around the world impacted by theProxy Statement SummaryCOVID-19 pandemic. The donations are focused on expanding testing options, easing the strain on medical systems and supporting access to necessities like food.

(continued)Our Pricing Principles

As a pioneer in neuroscience, we have the opportunity and responsibility to bring potentially transformative treatments to patients. Our patients remain at the center of everything we do as a company. We recognize that access and the price of our medicines are of concern to our patients, providers, payers and policy makers. We work collaboratively to help ensure that patients are not denied access to life-changing therapies and are guided by the following principles:

A copy of our Pricing Principles is posted on our website,www.biogen.com, under the “Guiding Principles” subsection of the “Who We Are” section of the website.

We regularly review our pricing strategy and prioritize patient access to our therapies. We have a value-based contracting program designed to align the price of our therapies to the value our therapies deliver to patients. We also work with regulators, clinical researchers, ethicists, physicians and patient advocacy organizations and communities, among others, to determine how best to address requests for access to our investigational therapies in a manner that is consistent with our patient-focused values and compliant with regulatory standards and protocols. In appropriate situations, patients may have access to investigational therapies through Early Access Programs, single patient access or emergency use based on humanitarian or compassionate grounds.

We believe biosimilar products benefit patients and help reduce the costs of healthcare systems. We estimate that theanti-TNF biosimilars we sell may have provided healthcare savings of approximately€1.8 billion in 2019 in the markets where they are sold.

Corporate Responsibility Report

For more information on our commitment to corporate social responsibility and stewardship, including environmental sustainability, diversity and inclusion, STEM education and other key initiatives, please see our Corporate Responsibility Report, which is posted on our website,www.biogen.com, under the “Corporate Responsibility” section of the website. We believe these efforts reflect the best interests of our patients, our stockholders, various stakeholders and the communities in which we operate and serve.

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We are committed to the highest standards of ethics, business integrity and corporate governance, which we believe will ensure that our company is managed for the long-term benefit of our stockholders. Our governance practices are designed to establish and preserve accountability of our Board of Directors and management, provide a structure that allows our Board to set objectives and monitor performance, ensure the efficient use and accountability of resources and enhance stockholder value. Please see Part 2 – “Corporate Governance at Biogen” for more information.

Corporate Governance Highlights

Director Stockholder Engagement Initiative

We value the views of our stockholders and other stakeholders, and we solicit input throughout the year. During 20182019 independent members of our Board of Directors met with several stockholders to discuss a variety of issues, including business strategy, capital allocation, corporate governance, executive compensation, sustainability and our corporate social responsibility initiatives.

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Proposal 1 — Election of Directors

You are being asked to vote on the election of the following 1412 nominees for director. All directors are elected annually by the affirmative vote of a majority of votes cast. Detailed information about each director’s background, skill sets and areas of expertise can be found beginning on page 11.

						Committee Memberships*												Other Public   Boards						Committee Memberships*						Other Public Boards
Name, Occupation and Experience		Age*		Independent		AC		C&MDC		CGC		FC		RC		STC				Age*		Independent		AC		C&MDC		CGC
John R. Chiminski* Chair of the Board, President and Chief Executive Officer, Catalent, Inc.		55		Yes														1
Alexander J. Denner, Ph.D. Founding Partner and Chief Investment Officer, Sarissa Capital Management LP		49		Yes														1		50		Yes								—
Caroline D. Dorsa Retired Executive Vice President and Chief Financial Officer, Public Service Enterprise Group Incorporated		59		Yes														3		60		Yes								3
William A. Hawkins* Senior Advisor, EW Healthcare Partners		65		Yes														1
William A. Hawkins Senior Advisor, EW Healthcare Partners																				66		Yes								1
Nancy L. Leaming Retired Chief Executive Officer and President, Tufts Health Plan		71		Yes														—		72		Yes								—
Jesus B. Mantas* Managing Partner and General Manager, IBM Global Services		50		Yes														—
Jesus B. Mantas Senior Managing Partner for Global Strategy, Platforms and Innovation, IBM Global Business Services																				51		Yes								—
Richard C. Mulligan, Ph.D. Mallinckrodt Professor of Genetics, Emeritus, Harvard Medical School and Executive Vice Chairman, Sana Biotechnology		64		Yes														—		65		Yes								—
Robert W. Pangia Retired Chief Executive Officer, Ivy Sports Medicine, LLC		67		Yes														—		68		Yes								—
Stelios Papadopoulos, Ph.D. Chairman, Biogen Inc., Chairman, Exelixis, Inc. and Chairman, Regulus Therapeutics Inc.		70		Yes														2		71		Yes								2
Brian S. Posner Private Investor and Founder and Managing Partner, Point Rider Group LLC		57		Yes														2		58		Yes								2
Eric K. Rowinsky, M.D. President and Executive Chairman, RGenix, Inc.		62		Yes														3		63		Yes								3
The Honorable Lynn Schenk, J.D. Attorney, Former Chief of Staff to the Governor of California and Former U.S. Congresswoman		74		Yes														1
Stephen A. Sherwin, M.D. Clinical Professor of Medicine, University of California, San Francisco and Advisor to Life Sciences Companies		70		Yes														3		71		Yes								3
Michel Vounatsos Chief Executive Officer, Biogen Inc.		57		No														—		58		No								1

* Age and Committee memberships are as of April 22, 2019. Messrs. Chiminski, Hawkins and Mantas are each new director nominees standing for election to our Board of Directors at the Annual Meeting.6, 2020.

Chair:		Member:		Financial Expert:

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Proposal 2 – Ratification of Independent Registered Public Accounting Firm

You are being asked to vote to ratify the selection of PricewaterhouseCoopers LLP as our independent registered public accounting firm for the year ending December 31, 2019.2020. Detailed information about this proposal can be found beginning on page 27.26.

Proposal 3 – Advisory Vote on Executive Compensation

Our Board of Directors recommends that stockholders vote to approve, on an advisory basis, the compensation paid to the Company’s named executive officers (NEOs) as described in this Proxy Statement (the“say-on-pay” vote). Detailed information about the compensation paid and awarded to our NEOs can be found beginning on page 30.29.

Our executive compensation programs embody apay-for-performance philosophy that supports our business strategy and aligns executive interests with those of our stockholders. Highlights of our executive compensation programs for 20182019 and our executive compensation best practices follow.

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This Proxy Statement contains forward-looking statements, including statements relating to: our strategy and plans; potential of our commercial business and pipeline programs; capital allocation and investment strategy; clinical development programs, clinical trials and data readouts and presentations; regulatory filings and the timing thereof; the potential benefits, safety, and efficacy of our products and investigational therapies; the anticipated benefits and potential of investments, collaborations and business development activities.activities; and the impact related to the effect ofCOVID-19 or other public health epidemics on our sales and operations, including employees, manufacturing and clinical trials. These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “plan,” “potential,” “possible,” “will,” “would” and other words and terms of similar meaning. You should not place undue reliance on these statements or the scientific data presented.

These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including the risks and uncertainties that are described in the Risk Factors section of our most recent annual or quarterly report and in other reports we have filed with the U.S. Securities and Exchange Commission (SEC). These statements are based on our current beliefs and expectations and speak only as of the date of this Proxy Statement. We do not undertake any obligation to publicly update any forward-looking statements, whether as a result of new information, future developments or otherwise, except as required by law.

AVONEX^®, PLEGRIDY^®, SPINRAZA^®, TECFIDERA^® and ZINBRYTAVUMERITY^® are registered trademarks of Biogen. BENEPALI^™, FLIXABI^™ and IMRALDI^™ is a trademarkare trademarks of Biogen. HUMIRALUCENTIS^®, EYLEA^® and other trademarks referenced in this Proxy Statement are the property of their respective owners.

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Biogen Inc.

225 Binney Street

Cambridge, Massachusetts 02142

The Board of Directors of Biogen Inc. is soliciting your proxy to vote at our 20192020 annual meeting of stockholders (Annual Meeting) to be held at 9:00 a.m. Eastern Time on Wednesday, June 19, 2019,3, 2020, for the purposes summarized in the accompanying Notice of 20192020 Annual Meeting of Stockholders. Our 20182019 Annual Report on Form10-K is also available with this Proxy Statement.

References in this Proxy Statement to “Biogen” or the “Company,” “we,” “us” and “our” refer to Biogen Inc.

1

We are asking our stockholders to elect the 1412 director nominees listed below to serve aone-year term extending until the 20202021 annual meeting of stockholders and until their successors are duly elected and qualified, unless they resign or are removed:

Our Board of Directors has nominated these 1412 individuals based on its carefully considered judgment that the experience, qualifications, attributes and skills of our nominees qualify them to serve on our Board of Directors. As described in detail below, our nominees have considerable professional and business expertise. We know of no reason why any nominee would be unable to accept nomination or election.

If any nominee is unable to serve on our Board of Directors, the shares represented by your proxy will be voted for the election of such other person as may be nominated by our Board of Directors. In addition, in compliance with all applicable state and federal laws and regulations, we will file an amended proxy statement and proxy card that, as applicable, (1) identifies the alternate nominee(s), (2) discloses that such nominees have consented to being named in the revised proxy statement and to serve if elected and (3) includes the disclosure required by Item 7 of Schedule 14A with respect to such nominees. All nominees have consented to be named in this Proxy Statement and to serve if elected.

Director Skills and Qualifications

The Corporate Governance Committee believes that the 1412 director nominees collectively have the skills, experience, diversity and character to execute the Board’s responsibilities. The following is a summary of those qualifications:

11

Our Nominees for Director

(Information is as of April 22, 2019)6, 2020)

12