Out With The New, In With The Old: Fifth Circuit Reinstates Legacy HSR Forms

Following an order from the US Court of Appeals for the Fifth Circuit, and effective immediately, the Federal Trade Commission (FTC) will return to using the prior Hart-Scott-Rodino (HSR) form that was in effect before February 2025, when the updated forms implementing the new HSR rules took effect.

In Depth

We previously wrote about the vacatur of the new HSR forms, which had been in use since February 2025, by a federal district court in East Texas. That order was later temporarily stayed by the Fifth Circuit while the parties briefed the FTC’s motion to stay the district court order pending appeal. On March 19, 2026, the Fifth Circuit denied the FTC’s motion for a further stay pending appeal. As a result, the legacy HSR form (i.e., the pre-February 2025 form) has now been reinstated.

The FTC’s Premerger Notification Office (PNO) has issued guidance stating that it is now “accepting HSR filings using the Form and Instructions that were in place before the February 10, 2025, effective date of the new rule.” According to the FTC’s guidance, parties may choose to submit HSR filings on the new HSR forms voluntarily. We expect that deal teams for transactions in their incipiency will elect to immediately return to filing on the old HSR forms.

The McDermott team is equipped to handle and timely file on both forms and will continue to advise clients on a case-by-case basis. For deals that raise no antitrust concerns, completing the HSR forms will likely be less burdensome. But for transactions that may raise antitrust issues, it may be in the parties’ interests to provide a cover letter or other materials containing some advocacy, as was done often in the past.  We encourage clients to discuss this with their antitrust counsel.

We will continue to monitor any further developments with the Fifth Circuit appeal and any additional FTC guidance. If you have questions regarding the impact of the transition back to the legacy HSR forms, reach out to your McDermott Will & Schulte counsel.

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