Professionals

Michael Kimberly

Partner

Co-Chair, Appellate and Critical Motions Practice

Overview
Experience
Credentials
Insights & News

Michael Kimberly heads the Firm’s Appellate and Critical Motions practice. He has argued more than 50 appeals in federal and state courts all across the country in matters of constitutional, administrative, ERISA, antitrust, criminal, banking, taxation, copyright, trademark, and labor and employment law. Michael’s appellate experience includes ten arguments before the Supreme Court of the United States, four arguments before the federal courts of appeals sitting en banc, and scores of additional arguments before every regional federal court of appeals and several state supreme courts. Across the 50-plus appeals that he has argued, all in private practice, Michael’s win record is better than two-for-three.

Michael is widely recognized as a leader of the Supreme Court bar. He was the youngest lawyer recognized as one of the “elite cadre of lawyers” who “dominate the Supreme Court bar” in Joan Biscupic’s 2014 special report for Reuters, The Echo Chamber. In the years since, his success litigating before the Supreme Court has earned him repeated recognition in various academic articles devoted to Supreme Court advocacy, including The Inside Track and The Elitification of the U.S. Supreme Court and Appellate Lawyering. Michael has also been ranked nationally by The Legal 500 since 2017 and Chambers USA since 2021 for his appellate work, having been praised as a “brilliant writer” and “incredibly strategic thinker.”

Michael is often retained to design and execute affirmative challenges to laws and regulations promulgated by local, state, and federal government entities. These cases typically include claims under the Administrative Procedure Act and, as often, various provisions of the Constitution important to the business community, including the Supremacy Clause, First Amendment, Commerce Clause, Takings Clause, and Due Process Clause.

Beyond that, Michael frequently collaborates with Winston’s renowned trial litigators, leveraging his depth of insight into appellate litigation to help shape strategies across cases and jurisdictions. He has briefed and argued scores of dispositive and other major motions in federal district courts across the country.

Michael is a graduate of the Yale Law School, where he was an editor of The Yale Law Journal and executive editor of Yale Law & Policy Review. Before that, Michael earned his master’s degree from the University of Pennsylvania and his undergraduate degree, summa cum laude, from Princeton University, where he majored in philosophy and molecular biology. Following law school, Michael clerked for Judge Michael Hawkins on the U.S. Court of Appeals for the Ninth Circuit. From 2015 through 2026, he was a member of the faculty of the Yale Law School, where he taught Supreme Court advocacy.

Key Matters

Some of the experience represented below may have been handled at a previous firm.

Recent Appellate Victories

Galette v. New Jersey Transit Corp., 146 S. Ct. 854 (2026) – secured a 9-0 Supreme Court decision holding that public corporations like NJ Transit are not “arms of the state” entitled to interstate sovereign immunity
Hewitt v. United States, 606 U.S. 419 (2025) – secured a surprise 5-4 Supreme Court victory in a criminal sentencing case that turned on detailed statutory text arguments
Nia v. Bank of America, --- F.4th ---, 2026 WL 981207 (9th Cir. 2026) – successfully defended summary judgment in a case concerning bank compliance policies adopted under the International Emergency Economic Powers Act
Boyette v. Montefiore Medical Center, 2025 WL 48108 (2d Cir. 2025) – successfully defended dismissal of ERISA breach-of-fiduciary-duty class action on standing and pleading grounds
Chamber of Commerce v. Lierman, 151 F.4th 530 (4th Cir. 2025); 90 F.4th 679 (4th Cir. 2024) – obtained repeat reversals and ultimate victory in a First Amendment challenge to a “no stating the tax” law
Medical Imaging Technology Association v. Library of Congress, 103 F.4th 830 (D.C. Cir. 2024) – successfully established that the Library of Congress is subject to suit under the APA
Appvion Retirement Savings and Employee Stock Ownership Plan v. Buth, 99 F.4th 928 (7th Cir. 2024) – successfully defended dismissal of an ERISA breach-of-fiduciary duty class action
Matter of Comptroller of Maryland, 328 A.3d 811 (Md. App. Ct. 2024) – retained by Potomac Edison to successfully appeal a tax court decision worth $10 million annually
Scott v. University of Chicago Medical Center, 107 F.4th 752 (7th Cir. 2024) – successfully defended the dismissal of a complaint concerning compelled vaccinations in the maternity ward
Medicaid & Medicare Advantage Products Association v. Emanuelli Hernandez, 58 F.4th 5 (1st Cir. 2023) – successfully defended invalidation of state law under Medicare preemption
BDO USA, LLP v. Jia-Sobota, 283 A.3d 699 (D.C. 2022) – obtained reversal of a denial of a motion to compel arbitration on waiver grounds
Louisiana Independent Pharmacies Association v. Express Scripts, 41 F.4th 473 (5th Cir. 2022) – successfully defended dismissal of a reverse-preemption suit on jurisdictional grounds
Virginia Hospital & Healthcare Association v. Kimsey, 2022 WL 604049 (4th Cir. 2022) – obtained reversal of the dismissal of a Medicaid preemption and Takings Clause case

Recent Regulatory Litigation Victories

Medicaid & Medicare Advantage Products Association v. Vega (D.P.R. 2026 & 2023) – following victory in the First Circuit in 58 F.4th 5 (1st Cir. 2023), obtained two additional victories invalidating, under Medicare preemption, various state-law enforcement efforts by the Puerto Rico Insurance Commissioner
Americans for Beneficiary Choice v. DHHS, 2024 WL 3297527 (N.D. Tex. 2024) – obtained preliminary injunction against enforcement of the Medicare Compensation Rule
International Fresh Produce Association v. DOL, – F. Supp. 3d – (S.D. Miss. 2024) – obtained preliminary injunction on preclusion grounds against a farm worker union rights regulation
Wild Virginia v. Council on Environmental Quality, 56 F.4th 281 (4th Cir. 2022) – intervened for trade groups in defense of favorable regulation, successfully obtaining dismissal of the suit

Recent Experience

End of the Line: Winston Wins Unanimous Supreme Court Victory Against NJ Transit

Capabilities

Advertising Litigation

Antitrust/Competition

Appellate & Critical Motions

Bankruptcy Litigation & Investigations

Class Actions & Group Litigation

Commercial Litigation & Disputes

Environmental Litigation & Enforcement

ERISA Litigation

Financial Services Litigation

Litigation/Trials

Mergers & Acquisitions

Product Liability & Mass Torts

Project Finance

Securities, M&A & Corporate Governance Litigation

Tax Controversy & Criminal Tax

Technology Antitrust

Trademark Litigation, Prosecution & Brand Protection

Construction

Key Matters

Some of the experience represented below may have been handled at a previous firm.

Recent Appellate Victories

Galette v. New Jersey Transit Corp., 146 S. Ct. 854 (2026) – secured a 9-0 Supreme Court decision holding that public corporations like NJ Transit are not “arms of the state” entitled to interstate sovereign immunity
Hewitt v. United States, 606 U.S. 419 (2025) – secured a surprise 5-4 Supreme Court victory in a criminal sentencing case that turned on detailed statutory text arguments
Nia v. Bank of America, --- F.4th ---, 2026 WL 981207 (9th Cir. 2026) – successfully defended summary judgment in a case concerning bank compliance policies adopted under the International Emergency Economic Powers Act
Boyette v. Montefiore Medical Center, 2025 WL 48108 (2d Cir. 2025) – successfully defended dismissal of ERISA breach-of-fiduciary-duty class action on standing and pleading grounds
Chamber of Commerce v. Lierman, 151 F.4th 530 (4th Cir. 2025); 90 F.4th 679 (4th Cir. 2024) – obtained repeat reversals and ultimate victory in a First Amendment challenge to a “no stating the tax” law
Medical Imaging Technology Association v. Library of Congress, 103 F.4th 830 (D.C. Cir. 2024) – successfully established that the Library of Congress is subject to suit under the APA
Appvion Retirement Savings and Employee Stock Ownership Plan v. Buth, 99 F.4th 928 (7th Cir. 2024) – successfully defended dismissal of an ERISA breach-of-fiduciary duty class action
Matter of Comptroller of Maryland, 328 A.3d 811 (Md. App. Ct. 2024) – retained by Potomac Edison to successfully appeal a tax court decision worth $10 million annually
Scott v. University of Chicago Medical Center, 107 F.4th 752 (7th Cir. 2024) – successfully defended the dismissal of a complaint concerning compelled vaccinations in the maternity ward
Medicaid & Medicare Advantage Products Association v. Emanuelli Hernandez, 58 F.4th 5 (1st Cir. 2023) – successfully defended invalidation of state law under Medicare preemption
BDO USA, LLP v. Jia-Sobota, 283 A.3d 699 (D.C. 2022) – obtained reversal of a denial of a motion to compel arbitration on waiver grounds
Louisiana Independent Pharmacies Association v. Express Scripts, 41 F.4th 473 (5th Cir. 2022) – successfully defended dismissal of a reverse-preemption suit on jurisdictional grounds
Virginia Hospital & Healthcare Association v. Kimsey, 2022 WL 604049 (4th Cir. 2022) – obtained reversal of the dismissal of a Medicaid preemption and Takings Clause case

Recent Regulatory Litigation Victories

Medicaid & Medicare Advantage Products Association v. Vega (D.P.R. 2026 & 2023) – following victory in the First Circuit in 58 F.4th 5 (1st Cir. 2023), obtained two additional victories invalidating, under Medicare preemption, various state-law enforcement efforts by the Puerto Rico Insurance Commissioner
Americans for Beneficiary Choice v. DHHS, 2024 WL 3297527 (N.D. Tex. 2024) – obtained preliminary injunction against enforcement of the Medicare Compensation Rule
International Fresh Produce Association v. DOL, – F. Supp. 3d – (S.D. Miss. 2024) – obtained preliminary injunction on preclusion grounds against a farm worker union rights regulation
Wild Virginia v. Council on Environmental Quality, 56 F.4th 281 (4th Cir. 2022) – intervened for trade groups in defense of favorable regulation, successfully obtaining dismissal of the suit