Emergent BioSolutions Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule 14a-101)

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Emergent BioSolutions Inc.

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2026NOTICE OFANNUALMEETING OFSTOCKHOLDERSAND PROXYSTATEMENT

Our Mission

At Emergent, our mission is to protect and save lives.

Our Vision

Our vision is to become the leader in solving health threats for communities around the world.

Our Capabilities

We are a leading public health company that delivers protective and life-saving solutions to communities around the world.

Commercial Products

We offer commercialized products that address endemic public health threats such as the opioid epidemic.

Medical Countermeasures

We specialize in developing, manufacturing, and stockpiling medical countermeasures for military and civilian populations that target some of the deadliest public health threats.

Dear Fellow Stockholders,

On behalf of the Board of Directors, I invite you to attend Emergent’s 2026 annual meeting of stockholders, to be held virtually on Wednesday, April 29, 2026, at 9:00 a.m., Eastern Time. You can attend the annual meeting by visitingwww.virtualshareholdermeeting.com/EBS2026, where you will be able to listen to the meeting live, submit questions and vote online.

Emergent has a long history of working with the U.S. government, allied nations and customers around the world to deliver products that protect against health threats. Over the past year, Emergent has taken strategic actions to strengthen the business and make significant progress in its turnaround. With a diverse portfolio of medical countermeasures and opioid overdose emergency products, Emergent is well positioned to execute its transformation strategy.

The Board of Directors is confident in Emergent’s ability to transform the business to deliver long-term, sustainable value for stockholders, while continuing the important work of protecting communities from health threats. We will continue working to provide strong governance and independent oversight to represent your interests as Emergent continues its turnaround and transformation for the future.

Thank you for your continued investment in Emergent and joining us in our mission to protect and save lives.

Sincerely,

Zsolt Harsanyi, Ph.D.

Chairman of the Board of Directors

March 20, 2026

YOUR VOTE IS IMPORTANTPLEASE TAKE TIME TO VOTE AS PROMPTLY AS POSSIBLE

Notice of 2026 Annual Meeting of Stockholders

TO OUR STOCKHOLDERS

The 2026 annual meeting of stockholders of Emergent BioSolutions Inc. will be held on April 29, 2026, at 9:00 a.m., Eastern Time. You will be able to attend the annual meeting, vote, and submit questions via live webcast by visitingwww.virtualshareholdermeeting.com/EBS2026.

The annual meeting will be held for the following purposes:

Only holders of our common stock at the close of business on March 6, 2026, the record date, are entitled to receive this notice and to attend and vote at the annual meeting. We are mailing this notice beginning on or about March 20, 2026 with instructions on how to access our proxy materials and vote online.

We have designed the format of the annual meeting to provide our stockholders with similar rights and opportunities to participate that they would have at an in-person meeting. You will be able to attend and participate in the annual meeting online, vote your shares electronically and submit your questions during the meeting by visitingwww.virtualshareholdermeeting.com/EBS2026, and entering the 16-digit control number on your Notice of Internet Availability of Proxy Materials, proxy card or voting instruction card. If you encounter any difficulties accessing the virtual meeting website, please call the technical support number that will be posted on the meeting log-in page.

By Order of the Board of Directors,

Jessica Perl

Senior Vice President, General Counsel and Corporate Secretary

Gaithersburg, MD

March 20, 2026

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON APRIL 29, 2026

The Company’s proxy statement for the 2026 annual meeting of stockholders and Annual Report on Form 10-K for the fiscal year ended December 31, 2025, are available atwww.proxyvote.com.

YOUR VOTE IS VERY IMPORTANT. WHETHER OR NOT YOU PLAN TO ATTEND THE MEETING VIA LIVE WEBCAST, WE URGEYOU TO VOTE PROMPTLY.

Table of Contents

Proxy Statement Summary

This summary highlights information contained elsewhere in this proxy statement and does not contain all of the information you should consider. You should read the entire proxy statement before voting.

Attend and Vote at Annual Meeting

Proposals, Board Recommendations and Required Vote

*The nominees who receive the most votes will be elected by stockholders.

How to Vote

If you are a stockholder of record, you may vote your shares:

Please review the section at the end of this proxy statement titled “QUESTIONS AND ANSWERS ABOUT THE ANNUAL MEETING” if you have additional questions about how to attend the meeting or other procedural questions about voting on matters to be presented at the meeting.