Federal Court Tosses New HSR Rules

By: Steve Albertson , Thomas Ensign , Meredith Mommers

What You Need To Know

  • The year-old revisions to the Hart-Scott-Rodino Act premerger notification regime have been found unlawful by a federal court in Texas and have been vacated.
  • The court stayed implementation of its order for one week to allow the FTC to appeal the decision to the Fifth Circuit Court of Appeals.
  • Pending any appeal and any further judicial action, significant uncertainty remains for parties to active transactions with pending filing obligations.
  • Deal parties soon may benefit from a return to less burdensome and time-consuming HSR reporting requirements that were in effect up to February 2025.

A federal judge in Texas has vacated the Federal Trade Commission’s adoption of a sweeping overhaul of the federal pre-merger notification regime that became effective in February 2025. The court found that the significant additional costs and burdens on transaction parties required to submit filings under the Hart-Scott-Rodino Act (HSR) were not justified by the asserted benefits to the federal antitrust agencies and thereby overstepped the FTC’s rulemaking authority.

In granting summary judgment to the U.S. Chamber of Commerce and other business groups who filed suit to block the new rules prior to their effective date, the court found the FTC’s adoption of the rules was undertaken without sufficient consideration of the costs and benefits of the move, and that the FTC’s action was therefore “arbitrary and capricious.” The court vacated and set aside the new rules, while granting a one-week stay of its order to allow the FTC to appeal to Fifth Circuit Court of Appeals.

Background

Shortly after her appointment, Biden-era FTC Chair Lina Khan asserted in 2021 that the HSR premerger review process did not provide the antitrust agencies sufficient information to adequately review proposed deals in a timely manner and announced her intention to revisit the HSR rules to fill perceived gaps.

Three years later, and after proposing and revising an initial proposed set of sweeping HSR rules changes, in October 2025 Khan announced a unanimous FTC vote to adopt the final version of the new rules. The new HSR rules imposed substantial additional costs and burdens on all filing parties through a raft of new and expanded requirements for disclosures of information and production of documents.

The U.S. Chamber of Commerce and other business groups to sued to have the new rules vacated on January 10, 2025. Notably, the Chamber’s complaint filed in the U.S. District Court for the Eastern District of Texas, did not request a preliminary injunction blocking implementation, and the rules became effective on February 10, 2025.

Necessary and Appropriate

The FTC’s rulemaking authority under the HSR Act flows from the language of the statute, which says that the FTC “shall require that the [premerger] notification ... be in such form and contain such documentary material and information relevant to a proposed acquisition as is necessary and appropriate to enable the [FTC and DOJ] to determine whether such acquisition may, if consummated, violate the antitrust laws” (emphasis added). The court interpreted “necessary and appropriate” to mean that the HSR Act “requires that any benefits to the FTC in mandating additional information in the premerger notice ‘reasonably outweigh’ the costs.”

The FTC argued that prior unlawful transactions had escaped the notice of the FTC and DOJ as a consequence of the agencies not having received the kinds of information required under the new rules, and thus that the new rules were “necessary and appropriate” to close this gap. However, the court found the claimed benefits were “illusory or, at least, unsubstantiated.” According to the court, the FTC failed to identify even a single historical instance of such a failure, and that the evidence the agency did produce tended to support a conclusion that the prior version of the rules was effective in carrying out the aims of the HSR Act.

In the absence of this basic justification for the imposition of substantial additional costs, according to the court, the FTC exceeded its statutory rulemaking authority under the HSR Act. The court held that because the FTC’s rulemaking did not satisfy the required analysis of costs and benefits, and because the FTC failed to properly consider less burdensome alternatives, the new rules were “arbitrary and capricious” and therefore also unlawful under the Administrative Procedures Act.

Key Takeaways

  • The FTC has not yet announced whether it will appeal the district court’s order, although at the time of this article’s publication the agency advised HSR filers to continue to use the new form through at least February 19, 2026.
  • Practically speaking, the stay means continuing to prepare to file under the new rules, as the information and documents needed for a filing under the old rules are a subset of what is required under the new rules.
  • If the HSR requirements revert to the rules in effect prior to February 10, 2025, deal parties can expect to face significantly less time and expense in preparing their filings, with corresponding benefits to overall deal timelines.
  • Fenwick will keep you apprised of further developments.