The Amazon antitrust class action lawsuit, formally titled De Coster v. Amazon.com, Inc., covers roughly 288 million U.S. consumers who bought new physical goods from third-party sellers on Amazon since May 26, 2017. A federal judge in Seattle certified the class on August 6, 2025, and trial is scheduled to begin June 14, 2027.1Quinn Emanuel Urquhart & Sullivan LLP. Quinn Emanuel Secures Historic Class Certification Victory for 200 Million Consumers in Landmark Antitrust Case Against Amazon2Amazon Antitrust Litigation. De Coster et al. v. Amazon.com Amazon denies the allegations, and no ruling on the merits has been reached.
Who Is in the Class
You are a member of the certified class if you live in the United States and, on or after May 26, 2017, purchased five or more new, physical goods from third-party sellers on Amazon’s marketplace.3Justia. De Coster v. Amazon.com Inc. Used goods, digital products, and prescriptions are not included.
You do not need to sign up, file anything, or take any action to remain in the class. Membership is automatic. No money or benefits are available now because the case has not been decided or settled. If the plaintiffs win at trial or Amazon settles, class members will receive notice explaining how to claim a share of any recovery.4Amazon Antitrust Litigation. De Coster v. Amazon.com Frequently Asked Questions
The court-appointed administrator, Epiq, began sending formal class notice in June 2026.5Hagens Berman Sobol Shapiro LLP. Amazon.com Antitrust (De Coster) If you shopped on Amazon during the covered period, you may receive an emailed or mailed notice, though notice is not required for you to be included.
What Amazon Is Accused of Doing
The lawsuit claims Amazon used pricing rules to stop third-party sellers from offering lower prices anywhere else — on eBay, Walmart, their own websites, or elsewhere online. Until 2019, Amazon’s seller contract carried an explicit “Price Parity Clause” banning cheaper listings on rival platforms. After Amazon dropped that clause, the plaintiffs allege the company kept enforcing the same rule through other tools.5Hagens Berman Sobol Shapiro LLP. Amazon.com Antitrust (De Coster)
The main enforcement mechanism, according to the complaint, is Amazon’s “Buy Box,” the prominent purchase button that generates the overwhelming share of sales on a product page. If Amazon’s automated systems detected a seller offering a lower price on another site, the seller could be suppressed or removed from the Buy Box, cutting off their sales on Amazon. Policies including the “Marketplace Fair Pricing Policy” and “Amazon’s Standards for Brands” allegedly backed up the same discipline.5Hagens Berman Sobol Shapiro LLP. Amazon.com Antitrust (De Coster)
The plaintiffs argue this harms consumers indirectly. Because sellers can’t undercut Amazon’s prices elsewhere, rival marketplaces have no room to compete on price, and that removes pressure on the fees Amazon charges sellers. Those fees can reach more than 40% of a sale’s revenue.6Robins Kaplan LLP. Amazon Antitrust Lawsuit Sellers pass those costs into the listed prices they charge everywhere, so consumers pay more across the online marketplace, not just on Amazon. The complaint alleges this violates Section 1 of the Sherman Act, which prohibits agreements that restrain trade.2Amazon Antitrust Litigation. De Coster et al. v. Amazon.com
Where the Case Stands
The lawsuit was filed on May 25, 2021, in the U.S. District Court for the Western District of Washington, case number 2:21-cv-00693, before Judge John H. Chun.7CourtListener. De Coster v. Amazon.com Inc. Judge Chun denied Amazon’s motion to dismiss in November 2024.5Hagens Berman Sobol Shapiro LLP. Amazon.com Antitrust (De Coster)
On August 6, 2025, in a 50-page opinion, Judge Chun granted class certification, accepting the economic analysis of MIT’s Dr. Parag Pathak that Amazon’s anti-discounting policies affected the entire class by suppressing price competition on platform fees.1Quinn Emanuel Urquhart & Sullivan LLP. Quinn Emanuel Secures Historic Class Certification Victory for 200 Million Consumers in Landmark Antitrust Case Against Amazon The court also found evidence that Amazon may have engaged in “privilege cloaking,” improperly marking ordinary business documents as attorney-client privileged.
Amazon opposed certification with more than 700 pages of briefing and sought immediate review by the Ninth Circuit. The appellate court denied that petition in September 2025, leaving the certification intact.8Law360. De Coster et al. v. Amazon.com Inc.
Trial was initially set for October 2026. In October 2025, Judge Chun moved it to June 14, 2027, to avoid conflicts with the California Attorney General’s separate case against Amazon. In January 2026, the court denied a request from the plaintiffs to bring the trial forward.8Law360. De Coster et al. v. Amazon.com Inc. No settlement has been announced.
How to Opt Out or Get Updates
Class members who want to exclude themselves must mail a signed, dated letter to:
De Coster v. Amazon.com, Inc.
Class Action Administrator
P.O. Box 5594
Portland, OR 97228-5594
Opt-out letters must be postmarked no later than August 31, 2026.4Amazon Antitrust Litigation. De Coster v. Amazon.com Frequently Asked Questions Excluding yourself means you give up any right to a share of a recovery in this case, but you keep the right to sue Amazon separately over the same conduct. Staying in costs nothing, and you’ll be bound by whatever outcome the case reaches.
The official case website is AmazonAntitrustLitigation.com, and the administrator’s phone number is 1-877-238-1874.5Hagens Berman Sobol Shapiro LLP. Amazon.com Antitrust (De Coster) Three firms serve as co-lead counsel for the class: Hagens Berman Sobol Shapiro, Keller Postman, and Quinn Emanuel Urquhart & Sullivan.9Keller Postman LLC. Keller Postman Appointed Co-Lead Class Counsel in Amazon Antitrust Class Action
Other Amazon Antitrust Cases You May Have Heard About
Several other Amazon antitrust cases are moving through the courts. They are separate from De Coster and won’t put money in your pocket through this class, but they overlap in subject matter and often surface in the same news stories.
Frame-Wilson v. Amazon.com, Inc. (No. 2:20-cv-00424) represents consumers who bought products on eBay and Walmart at prices allegedly inflated by Amazon’s policies, rather than purchases made on Amazon itself. A motion for class certification is pending before Judge Chun.10Hagens Berman Sobol Shapiro LLP. Amazon Antitrust (Frame-Wilson)
Brown v. Amazon.com, Inc. (No. 2:22-cv-00965) targets “Minimum Margin Agreements” between Amazon and its first-party suppliers, under which suppliers reportedly must reimburse Amazon if Amazon lowers a retail price to match a competitor.11Classaction.org. Brown et al. v. Amazon.com Inc.
The Federal Trade Commission and 17 state attorneys general plus Puerto Rico filed their own antitrust case against Amazon on September 26, 2023 (No. 2:23-cv-01495, W.D. Wash.), alleging monopoly maintenance through anti-discounting penalties and Prime-related conduct.12New York Attorney General. Attorney General James, FTC and Multistate Coalition Sue Amazon That case is also before Judge Chun and is set for trial October 13, 2026.13Bloomberg Law. Amazon Poised for Late 2026 Trial in FTC Monopoly Power Lawsuit
California Attorney General Rob Bonta is pursuing a state case in San Francisco Superior Court (CGC-22-601826), with trial scheduled for January 19, 2027.14California Office of the Attorney General. Attorney General Bonta Delivers Victory Against Amazon in Ongoing Price Case Government enforcement cases like the FTC and California actions seek injunctions and civil penalties rather than consumer refunds, so they operate on a different track from the De Coster class action.