Maureen represents clients in all areas of customs law and international trade litigation. She is a licensed customs broker and has particular expertise in classification and country of origin analyses, obtaining tariff exclusions and duty reductions, the development of customs compliance programs, compliance with Free Trade Agreement (FTA) rules, obtaining import permits and licenses, and participation in the Customs-Trade Partnership Against Terrorism (C-TPAT). She collaborates regularly with the firm's various regulatory practice groups covering agencies such as the U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA) that regulate the importation of products within their regulatory jurisdiction. Representative industries to which she has provided advice include consumer electronics, batteries, metals, chemicals, pharmaceuticals, footwear, aerospace, tobacco, automobiles, frozen foods, semi-conductors, lawn and garden products, pet foods, and toys. Maureen also specializes in antidumping and countervailing litigation before the U.S. Court of International Trade and the U.S. Court of Appeals for the Federal Circuit, where she has successfully represented a range of U.S. companies including steel, office products, and tool manufacturers.
Clients have described Maureen as “extremely knowledgeable about tariffs” and say that she “guides us through the process seamlessly” (Chambers USA 2021) while giving "practical and responsive" advice (The Legal 500 US 2016).
- Prepared successful customs compliance programs, prior disclosures, and protests for clients with a multinational manufacturing base.
- Obtained favorable rulings for clients in proceedings before U.S. Customs and Border Protection (CBP), and in antidumping/countervailing duty investigations, administrative reviews, and sunset reviews before the U.S. Department of Commerce (DOC) and the U.S. International Trade Commission (USITC).
- Obtained exclusions from Section 301 tariffs on consumer electronics, specialty textiles, sporting goods, and hardware products.
- Evaluated import transactions for FTA duty-free status, including preparation of successful responses to North American Free Trade Agreement (NAFTA) and U.S.-Korea FTA verification requests for U.S. metals, foods, and chemical producers, and obtaining NAFTA country customs rulings.
- Assisted firms across industries including chemicals, pesticides, pharmaceuticals, metals, and textiles in assessing country of origin labeling requirements and compliance for import and export sales, as well as determining eligibility for “Made in USA” claims under both federal and state law.
- Assisted companies in an array of industries, including metals, tools, and office products with CBP focused assessments and in obtaining ruling letters and statistical tariff breakouts.
- Represented companies before CBP in Enforce and Protect Act (EAPA) proceedings regarding antidumping and countervailing duty investigations.
- Assisted companies in industries as diverse as pesticides, pharmaceuticals, pet products, automobiles, and oil and gas surveying with obtaining import permits and complying with import regulations administered by agencies such as the USDA, the FDA, the U.S. National Highway Transportation & Safety Administration (NHTSA), the Federal Trade Commission (FTC), the U.S. Fish & Wildlife Service (FWS), and the EPA.
- Represented clients in trade litigation before the U.S. Court of International Trade and the U.S. Court of Appeals for the Federal Circuit, including challenges to tariff rates.
- Research Assistant, Harrison Institute for Public Law (2001-2003)
- Legal Clerk, U.S. Federal Trade Commission (2002)
- Legal Clerk, Electronic Privacy Information Center (2001)
- U.S. Court of International Trade, Advisory Committee (2012-Present)
- American Bar Association (ABA), Section of International Law
- Co-Chair, International Trade Committee (2015-2017)
- Customs Law Committee
Listed by Chambers USA as one of “America’s Leading Lawyers for Business” in International Trade: Customs (2021)
- Recognized by Law360 as a "Rising Star" in International Trade (2015)
- Named one of DC's "Super Lawyers" (2019-2020, 2022) and "Rising Stars" (2014-2018) for International by Super Lawyers magazine
- Recognized by The Legal 500 US in International Trade (2015-2017, 2021)
J.D., cum laude, Georgetown University Law Center
B.A., with distinction, University of Virginia; Phi Beta Kappa
Member, Law and Policy in International Business
- Law Clerk for The Honorable Donald C. Pogue, U.S. Court of International Trade (2003-2005)
Bar and Court Memberships
- District of Columbia Bar
- U.S. Court of Appeals for the Federal Circuit
- U.S. Court of International Trade
Licensed U.S. Customs Broker
Related News & Insights
- Media MentionTim Brightbill, Maureen Thorson Quoted in Coverage of Webinar on Special Import TariffsInternational Trade TodayMay 20, 2022
- Event2022 Wiley International Trade Series: U.S. Special Import Tariffs – Where Do We Go From Here?WileyMay 12, 2022
- AlertU.S. International Trade Commission Opens Investigation into Impact of Section 232 and Section 301 DutiesAlan H. Price, Timothy C. Brightbill, Hon. Nazak Nikakhtar, Maureen E. Thorson, Christopher B. WeldMay 6, 2022
- AlertUSTR Announces “Reviews of Necessity” of Section 301 Duties on Chinese GoodsMaureen E. ThorsonMay 4, 2022