US v. Google (ad tech): remedies ruling declines to force AdX sale

In September 2026, Judge Leonie Brinkema issued her remedies ruling in the landmark US Department of Justice antitrust case against Google's ad tech business, declining to order the forced divestiture of Google's AdX ad exchange. This decision came after the court had previously found Google liable for illegally monopolizing the publisher ad server market and the ad exchange market through anticompetitive conduct. The DOJ and a coalition of state attorneys general had sought structural remedies including the forced sale of AdX and potentially Google Ad Manager, arguing that only divestiture could restore competition. Judge Brinkema instead opted for behavioral remedies, which may include requirements around interoperability, data access, pricing transparency, or restrictions on tying practices between Google's ad tech stack components.

The ruling represents a significant, if partial, victory for Google, as forced divestiture of AdX would have been one of the most consequential structural breakups of a major tech company in decades. By opting for behavioral remedies rather than structural ones, the court leaves Google's integrated ad tech stack largely intact, though compliance obligations could still meaningfully alter how Google operates its publisher-side ad tech business. For the broader AdTech ecosystem, this means competitors such as The Trade Desk, Magnite, PubMatic, and Index Exchange will not benefit from the competitive reset that a Google AdX divestiture would have created. Publishers and advertisers may see incremental improvements through mandated interoperability or transparency requirements, but the fundamental market structure — with Google controlling dominant positions across the buy side, sell side, and exchange layer — remains largely unchanged. The ruling is likely to be appealed by the DOJ, and the specific behavioral remedies imposed will be closely scrutinized by the industry for their practical enforceability and competitive impact.