Proskauer

Lucas Kowalczyk is a senior counsel in the Litigation Department and a member of the Appellate Group. Lucas has authored dozens of briefs in federal and state appellate and trial courts, as well as at the certiorari and merits stages in the U.S. Supreme Court. He has argued cases in both state and federal appellate courts. His work spans high-stakes constitutional, labor and employment, antitrust, intellectual property, bankruptcy, and commercial disputes.

Lucas has experience across a wide range of industries, from financial services and consumer products to sports, entertainment, telecommunications, and life sciences. He has represented many prominent companies and institutions, including the NBA, MLB, Los Angeles Lakers, T-Mobile, Church & Dwight, Ernst & Young, Cedars-Sinai, NBCUniversal, the Recording Academy, Michaels Stores, Toll Brothers, Sandoz, and Bloomberg, L.P., among others.

His notable appellate matters include several victories at the U.S. Supreme Court. Most recently, in May 2026, he prevailed on behalf of the Trustees of the IAM National Pension Fund before the Supreme Court in a unanimous decision resolving a circuit split over how multiemployer pension plans calculate withdrawal liability under ERISA. The Proskauer team was recognized by Law360 as “Legal Lions” for the victory. Lucas also helped secure a critical Supreme Court win for the Financial Oversight and Management Board for Puerto Rico—the entity created by Congress to oversee Puerto Rico’s bankruptcy, the largest in American history—in an appeal concerning the Board’s sovereign immunity.

Lucas is also a member of the firm’s White-Collar Defense & Investigations Group and Regulatory & Compliance Group, where his practice focuses on government and internal investigations, regulatory matters, and advising organizations navigating novel legal questions in rapidly evolving industries. He has conducted internal investigations involving employment, corporate-governance, and banking-regulatory issues, and has counseled companies responding to government inquiries and subpoenas, including by preparing employees for government interviews and testimony. Lucas has also represented high-ranking principals of major international financial institutions in multi-agency government investigations.

Finally, Lucas has successfully defended clients in high-stakes contractual disputes involving financial services, consumer goods, telecommunications, and other industries in trial courts and arbitrations.

Lucas maintains a diverse pro bono practice and has represented indigent clients in immigration, family, and appellate courts, and in death penalty proceedings. Among his notable cases, Lucas prevailed in a Second Circuit appeal regarding the government’s burden in justifying the continued detention of a noncitizen in removal proceedings. Lucas has received the Legal Aid Society’s Pro Bono Publico Award and Proskauer’s Golden Gavel Award for obtaining a critical victory for his client—an indigent grandmother acting as guardian for her two learning-disabled grandchildren—in an appeal argued by Lucas before the New York State Appellate Division, First Department. The court held that an amendment to New York’s Subsidized Kinship Guardian Program applied retroactively and required an award of benefits to the client’s grandchildren.