HSR Overview: Case Study of Two Real Companies

The Hart-Scott-Rodino Act (HSR) serves as the premerger gatekeeper for large deals, and in 2025 the thresholds rose again, so you must know when you’re in or out and how to prepare for the 30-day waiting period plus potential Second Requests. In my experience, the key is identifying whether your deal triggers HSR early, because a misstep can stall closing, trigger penalties, and delay value realization.

Overview

The HSR Act requires parties to notify the FTC and DOJ Antitrust Division before closing certain mergers and acquisitions, observe a 30-day waiting period, and file a Notification and Report Form if thresholds are met. This review flags potential anticompetitive effects and allows agencies time to request more information. Extensions occur via Second Requests, which add weeks or months. In 2025, thresholds rose by 5.8% due to GNP changes. The minimum threshold for notification moved to $126.4 million, and the tiers scale up to $505.8 million, with larger deals remaining under review. Filing fees follow a tiered structure, starting around $30,000 and increasing with deal value.

Thresholds and timing matter

The revised size-of-transaction thresholds for 2025 are as follows: transactions valued at $126.4 million or less generally do not trigger HSR filing; deals above that and below $505.8 million require filing only if the size-of-person test is met; deals at or above $505.8 million trigger HSR regardless of size-of-person. There are additional notification tiers for subsequent acquisitions, and the thresholds align with increments in the hundreds of millions.

The revised rule also adjusted the $100 million test for certain reviews to $252.9 million. In practice, many mid-market deals now fall outside HSR, but many still cross the line, so you must verify early.

Penalties keep rising

Civil penalties for gun-jumping, pre-closing coordination or actions that suggest closing is imminent, have climbed. As of January 17, 2025, the daily penalty rose to $53,088. Courts treat each day in violation as a separate violation, so delays compound quickly. Enforcement emphasizes filing on time and actions during the waiting period. In 2025, DOJ and FTC continued to push post-closing scrutiny for non-reportable deals if there’s evidence of anticompetitive effects, and they maintain close watch on incomplete or late filings.

Enforcement posture and strategy

The new FTC era emphasizes remedies and compliance measures rather than outright blocks in some cases, though blocks remain a tool for high-risk deals. The 2023 Merger Guidelines and the 2025 HSR form enhancements reflect a more granular data collection approach. Expect more detailed initial filings and longer preparation times, FTC guidance has nudged filing preparation time up by about 68 hours in some scenarios, which matters when coordinating internal teams, outside counsel, and the target’s counsel. Agencies show willingness to pursue gun-jumping penalties and late filings, with settlements in 2025 underscoring this trend.

Case study: CVS Health and Aetna

In 2018, CVS Health and Aetna closed their merger after HSR review. The deal valued at roughly $69 billion. Under HSR, CVS and Aetna filed the required notifications and followed the 30-day waiting period, during which agencies reviewed potential anticompetitive effects in health insurance markets and pharmacy services. Agencies ultimately approved the transaction with conditions, emphasizing continued oversight and divestitures in certain markets to address competitive concerns.

This case illustrates the typical trajectory: threshold-driven filing, a defined waiting period, potential information requests, and a consent-like order with behavioral or structural remedies. It also shows how a large deal can proceed with careful compliance, clear data, and active engagement with the agencies to address concerns.

For a timely lens

For a timely lens, consider recent enforcement actions where gun-jumping penalties were central. In 2025, a prominent case involved a buyer and seller in a reportable deal where the DOJ asserted gun-jumping behavior and pursued a settlement in the $5.6 million range. Public-facing details named the entities only as parties to a reportable M&A agreement, but the outcome underscored two points I rely on: first, the risk spike when a buyer acts on pre-closing control signals; second, the value of documenting all interim steps, pricing, and production plans during the waiting period. This is why precise internal controls and a formal timeline matter.

What this means for practice today

1. Map deals to thresholds early. Use the 2025 thresholds to determine if HSR filing is required, and forecast the timing of any Second Requests.
2. Harden the internal plan for the waiting period. Define who can make changes to operations, pricing, supplier contracts, or capex, and lock those policies in as early as possible.
3. Prepare detailed, accurate filings. The HSR form now expects more granular data; delays or inaccuracies invite penalties.
4. Anticipate potential post-closing remedies. Even when a deal clears the HSR process, expect conditions or divestitures in sensitive markets, plan for those up front.
5. Track enforcement trends. The DOJ/FTC emphasis on non-reportable deal scrutiny post-closing requires a robust post-merger integration control plan that preserves competitive structure in affected markets.

Practical takeaways. If you’re closing a deal in 2025 or later, confirm whether your transaction crosses the $126.4 million threshold or the $505.8 million threshold, and whether the size-of-person test applies. Prepare for higher filing fees, more detailed data requests, and a potentially longer review timeline. Plan for a Second Request (FTC/DOJ information-demand process to obtain more data during HSR review) and build a cross-functional team that can supply information quickly. Track penalties and ensure governance allows timely, compliant actions during the waiting period.

For readers who want to go deeper, we’ll continue translating the evolving HSR landscape into practical steps for your next deal. Our Matactic glossary provides more terms and examples to help with deal structuring, antitrust risk assessment, and post-merger integration. If you’re serious about navigating these rules, sign up for our free M&A course and follow for more deep dives on HSR thresholds, filing procedures, and real-world case studies. In my opinion, staying ahead means understanding both the numbers and the process, not just the headlines. We must consider how thresholds shift, how penalties scale, and how your deal team aligns with regulatory expectations to keep deals moving.

End with action

Review your deal against the 2025 HSR thresholds, audit your internal controls for the waiting period, and prepare the Notification and Report Form with a focus on accuracy and completeness. Then stay tuned for more terms explained through real cases and practical guidance in Matactic.