Key Takeaways from the FTC and DOJ’s Proposed Rule Changes
The Hart-Scott-Rodino (HSR) Act—a foundational element of U.S. antitrust merger review—is undergoing its most significant transformation since its enactment in 1976. In late 2024, the Federal Trade Commission (FTC), with the concurrence of the Department of Justice (DOJ), finalized sweeping changes to the HSR premerger notification rules and filing requirements. These reforms, which took effect on February 10, 2025, are designed to modernize the merger review process, provide regulators with earlier insight into potentially anticompetitive deals, and better align enforcement with today’s complex market realities.
This blog outlines the major changes and examines their implications for dealmakers, legal teams, and compliance professionals working through today’s shifting antitrust environment.
Major Changes in the 2025 HSR Rules
- Expanded Disclosure Requirements
The 2025 HSR reforms significantly expand disclosure requirements, placing a greater burden on merging parties. Filers are now required to submit significantly more detailed information and documentation, including expanded disclosures on ownership and control structures, minority holdings, investment ties, strategic deal rationale, past acquisitions, competitive overlaps, supply chain connections, labor market considerations, and related foreign merger control filings. These changes aim to give regulators a more comprehensive early view of potential antitrust concerns.
- Increased Preparation Burden
The FTC expects a significant increase in the time required to prepare HSR filings under the proposed rules, with an average of 105 hours—68 hours more than before. For complex deals involving competitive overlaps or supply relationships, preparation may take up to 121 hours or more. This heightened burden reflects the expanded disclosure requirements and increased document submissions under the proposed rules. As a result, deal teams will need to allocate more time and resources earlier in the transaction timeline to ensure compliance.
- Additional Document Requirements
Among the key changes in the 2025 HSR reforms is the expansion of document submission requirements. Filers are now required to provide a wider range of materials, including ordinary course and deal-related documents, draft agreements, and records from a broader set of custodians. The scope of 4(c) and 4(d) documents has also been broadened to include discussions of investment rationales, growth strategies, and market positioning—even in non-final draft form.
- Organizational and Ownership Disclosures
Greater transparency is now required under the 2025 HSR reforms regarding organizational and ownership structures. Filers must disclose detailed information about control, affiliate relationships, minority interests, and interlocking directorates. The reforms also introduce reporting obligations for certain foreign subsidies, reflecting heightened national security and geopolitical concerns in merger review.
- Implications for Deal Strategy
Deal planning is now more complex under the 2025 HSR reforms. Parties must conduct deeper pre-filing diligence to assess competitive overlaps, labor market effects, and documentation risks. With more detailed information required, agencies are better positioned to spot potential antitrust issues—raising enforcement risk even for deals that previously seemed low-risk.
Threshold Adjustments and Enforcement
In 2025, the FTC increased the HSR filing thresholds, setting the minimum reportable transaction value at $126.4 million and adjusting the size-of-person criteria and filing fees to reflect inflationary changes. However, penalties for non-compliance remain severe, with daily fines of up to $51,744.
Implications for Businesses and Counsel
The proposed reforms mark the most significant overhaul of the HSR process in over four decades, requiring earlier involvement of antitrust counsel and more strategic deal planning. By demanding broader disclosures, the FTC and DOJ aim to identify antitrust risks—such as nascent competition and vertical relationships—at the outset, signaling a shift toward more proactive merger enforcement.
The 2025 HSR reforms signal a major shift in U.S. merger control, prioritizing transparency, early antitrust risk detection, and heightened regulatory scrutiny. As filings become more detailed and reviews more intensive, early legal and strategic planning will be critical for navigating the more demanding premerger process.