


DeMario Carswell's practice focuses on ERISA litigation, government investigations, complex commercial litigation, and dispute resolution. He counsels and represents fiduciaries, plan sponsors, benefit plan service providers, and trustees in all phases of complex ERISA litigation, class action litigation and ERISA compliance. His work involves employer-sponsored benefit plans including defined contribution plans, employee stock ownership plans (ESOPs), insurance products, and other benefit plans. DeMario represents clients in regulatory investigations and enforcement proceedings, including those involving the Department of Labor (DOL).
DeMario advises fiduciaries on their fiduciary responsibilities and obligations under ERISA, helping clients proactively develop litigation risk mitigation strategies for benefit plans and their service providers.
DeMario's practice also includes assisting commercial clients and financial institutions in a variety of complex litigation matters — including employment, breach of contract, breach of fiduciary duty, consumer finance, and other financial services and products — in federal and state courts across the country, as well as pre-litigation counseling, mediation and arbitration, regulatory investigations and proceedings.
Before joining Miller & Chevalier, DeMario was a senior associate at a multinational law firm. He previously served as ERISA counsel at M&T Bank and its subsidiary, Wilmington Trust, where he managed ERISA litigation and regulatory matters nationwide. In that role, he also advised business lines and fiduciary committees on a range of ERISA-related issues. His in-house experience provides him with a unique perspective on the day-to-day challenges his clients face and how to position them for success.
DeMario has an active pro bono practice, representing 501(c)(3) organizations in litigation-related disputes, advocating for prisoners in civil rights cases, and assisting clients with immigration matters. He began his legal career as a litigation associate in the financial services department at a national law firm, representing national, regional, and local financial institutions in commercial litigation matters.
- Best Lawyers: Banking and Finance Law (Ones to Watch), 2024 - 2025
- Legal 500: Labor & Employment: ERISA Litigation, 2022
- Member, New York State Bar Association
- Member, Illinois State Bar Association
- Member, Advisory Committee on Fiduciary Issues, The ESOP Association (TEA)
- Former Board Member, National Federation for Just Communities
State Admissions
- District of Columbia
- New York
- Illinois
- Missouri (inactive)
Court Admissions
- United States District Court for the Southern District of Illinois
- United States District Court for the District of Maryland
- United States District Court for the Eastern District of Missouri
- United States District Court for the Southern District of New York
- United States Court of Appeals for the Eighth Circuit
- United States Court of Appeals for the Eleventh Circuit