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Jason Zweig is a Partner at Keller Postman LLC. He holds an impressive record of successful outcomes for clients across antitrust, consumer, products-liability, and securities matters. He has practiced in federal district and appellate courts throughout the country and has extensive experience in multidistrict litigation.

At Keller Postman, Jason focuses on class-action matters, including antitrust and consumer protection. He represents individuals, States and public institutions, and corporations as plaintiffs.

Before joining Keller Postman, Jason was the managing partner of the Chicago office of Hagens Berman Sobol Shapiro LLP, a national class-action and complex litigation firm. He moved to Chicago in 2015, having joined Hagens Berman in 2011 to open and lead the firm’s New York office. 

At Hagens Berman, he litigated antitrust, consumer-rights, product-liability, and securities cases. Among other notable matters, he led the firm’s representation of merchants who opted out of the class settlement in In re Payment Card Interchange Fee and Merchant Discount Litigation, including FedEx, American Airlines, Southwest Airlines, Alaska Airlines, JetBlue, British Airways, Hawaiian Airlines, DSW, and The Minnesota Twins.

Prior to joining Hagens Berman, Jason was a partner at Kaplan Fox & Kilsheimer LLP in New York. At Kaplan Fox, he played significant roles in numerous class actions, including the High Fructose Corn Syrup Antitrust Litigation (recovered $531 million), Hydrogen Peroxide Antitrust Litigation (recovered $97 million), and the Plastics Additives Antitrust Litigation (recovered $46.8 million). 

Jason is listed on Lawdragon’s Leading Plaintiff Financial Lawyers, National Trial Lawyers’ Top 100, and Illinois Super Lawyers.

Jason is also admitted to practice before the Department of Veterans Affairs and volunteers his time to assist military veterans with various matters.

Jason began his legal career at Proskauer Rose LLP in New York. He earned his law degree from Columbia Law School, where he was the Executive Editor for the Columbia Journal of Environmental Law. During law school, he was an intern for the Honorable Jed S. Rakoff, United States District Court Judge for the Southern District of New York. Jason earned his bachelor’s degree in public affairs from Indiana University.

Jason is licensed to practice law in Illinois and New York only.