Fifth Circuit Refuses to Stay District Court Decision Voiding New HSR Rules

On March 19, 2026, the U.S. Court of Appeals for the Fifth Circuit denied the Federal Trade Commission’s (“FTC”) motion for a stay pending appeal of a Texas district court judgment vacating the FTC’s 2024 overhaul of the Hart‑Scott‑Rodino (“HSR”) filing requirements.

Here are five important takeaways:

1. For now, the “old” HSR rules are back.
Effective immediately, filing parties may revert to the pre‑Feb. 10, 2025, HSR form and instructions. The FTC has confirmed it is accepting filings under the prior, less burdensome framework (while also accepting voluntary submissions on the 2025 form).

This development removes a potential speed bump for some mergers and acquisitions, reducing transaction friction, and could portend more activity in light of the less burdensome HSR process. While it is still too early to state definitively what will happen when the Fifth Circuit considers the merits of the FTC’s case, it represents a positive development for companies with HSR-reportable deals. As of now, we are back to the pre-2025 rules and form. The rules governing whether a deal is reportable under the HSR Act, as well as the annual thresholds and filing fee adjustments, are not affected by this ruling.

2. The Texas challenge that toppled the new rules—briefly.
In Chamber of Commerce of the United States of America v. FTC (E.D. Tex.), a coalition of business groups challenged the 2024 rulemaking that expanded HSR disclosures, arguing the FTC exceeded its statutory authority and acted arbitrarily and capriciously under the Administrative Procedure Act. On Feb. 12, 2026, the district court granted summary judgment for plaintiffs and vacated the rules in full, holding that the FTC exceeded its HSR Act authority—particularly the statute’s “necessary and appropriate” standard—and that the agency failed to justify the additional burdens with a reasoned cost‑benefit analysis, rendering the rules arbitrary and capricious. An administrative stay briefly kept the new form in place until the Fifth Circuit’s March 19 order ended that stay.

3. How we got here: the 2024–2025 HSR overhaul and projected burdens.
The FTC finalized sweeping changes to the HSR form on Oct. 10, 2024, with the Federal Register notice setting an effective date of Feb. 10, 2025. The new HSR rules imposed significantly increased burdens on filers, resulting in markedly higher preparation time and cost. The agency framed the new rules as closing “information gaps,” but acknowledged substantial added work for filers; contemporary practitioner guidance—summarizing the FTC’s own estimates—projected average preparation time of roughly 105 hours per filing (significantly higher for some acquirers). The revised rules required, among other things, written statements of deal rationales, detailed competitive overlap descriptions and analysis, certain reports prepared in the ordinary course of business, drafts of certain documents, and significant information about customer and supply relationships.

4. Signals from the stay denial.
Stay decisions are not merits rulings, but the Fifth Circuit’s refusal to keep the new rules alive pending appeal suggests the panel did not find the FTC’s likelihood of success or the equities compelling enough to override the district court’s analysis—an indicator (though not a guarantee) that the Fifth Circuit may ultimately affirm and leave the rules void.

5. Practical takeaway: good news—at least for now—for HSR filers.
Reversion to the prior HSR form reduces near‑term filing cost, lead‑time and documentary scope for most transactions, restoring a more predictable process while the appeal proceeds. Parties should still plan for potential agency follow‑ups (e.g., voluntary access letters or Second Requests) on transactions raising substantive antitrust issues, but the front‑end compliance lift is materially lighter under the old regime. For the more than 90% of HSR-reportable deals that present no competitive issues, this is good news indeed.

This document is intended to provide you with general information regarding the Fifth Circuit’s order denying appeal in U.S. Chamber of Commerce v. Fair Trade Commission. The contents of this document are not intended to provide specific legal advice. If you have any questions about the contents of this document or if you need legal advice as to an issue, please contact the attorneys listed or your regular Brownstein Hyatt Farber Schreck, LLP attorney. This communication may be considered advertising in some jurisdictions. The information in this article is accurate as of the publication date. Because the law in this area is changing rapidly, and insights are not automatically updated, continued accuracy cannot be guaranteed.