FTC Merger Review Process and Pre-Merger Notification

The FTC merger review process is the federal mechanism through which proposed acquisitions, mergers, and certain other transactions are evaluated for potential anticompetitive effects before they are consummated. Grounded in the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (15 U.S.C. § 18a), the pre-merger notification system requires qualifying parties to file with the FTC and the Department of Justice before closing, giving regulators a defined window to investigate. This page covers the statutory thresholds, procedural phases, key decision points, and contested dimensions of the review framework.

• Definition and scope
• Core mechanics or structure
• Causal relationships or drivers
• Classification boundaries
• Tradeoffs and tensions
• Common misconceptions
• Checklist or steps (non-advisory)
• Reference table or matrix

Definition and scope

The pre-merger notification requirement under the Hart-Scott-Rodino (HSR) Act applies to transactions that exceed specific size-of-transaction and size-of-person thresholds, which the FTC adjusts annually for inflation. For fiscal year 2024, the base size-of-transaction threshold was set at $119.5 million (FTC HSR Threshold Adjustments, 2024). Transactions that exceed this threshold and meet the size-of-person tests require the acquiring and acquired persons to submit HSR filings and observe a waiting period before closing.

The scope of the review extends beyond simple stock acquisitions. Asset purchases, mergers, certain joint ventures, and the acquisition of non-corporate interests can all trigger notification obligations depending on structural facts. The FTC's Bureau of Competition holds primary institutional responsibility for evaluating whether a notified transaction presents a substantial risk of substantially lessening competition under Section 7 of the Clayton Act (15 U.S.C. § 18).

The geographic scope is national. Any transaction meeting the HSR thresholds that involves parties with nexus to U.S. commerce — regardless of whether both parties are domiciled in the United States — may require notification. Foreign-to-foreign transactions are subject to specific exemption analyses under the FTC's rules at 16 C.F.R. Part 801.

Core mechanics or structure

Filing and the initial waiting period

Once both parties submit complete HSR filings, a mandatory initial waiting period begins. For most transactions, this period is 30 calendar days. For cash tender offers and bankruptcy transactions, the initial period is 15 calendar days (16 C.F.R. § 803.10). During this window, staff from the Bureau of Competition and the Bureau of Economics review the filing, assess market overlaps, and determine whether a deeper investigation is warranted.

Second Request

If the initial review raises competitive concerns, the agency may issue a Second Request — a formal demand for documents and data that substantially extends the waiting period. The parties must substantially comply with the Second Request before the clock restarts. After substantial compliance, the reviewing agency receives an additional 30-day period to complete its investigation. Second Requests are resource-intensive; compliance routinely involves production of millions of documents and detailed interrogatory responses.

Clearance allocation between FTC and DOJ

Jurisdiction over HSR filings is divided between the FTC and the Department of Justice Antitrust Division. The two agencies clear specific transactions to one or the other through an informal "clearance" process based on each agency's established expertise in particular industries. Pharmaceutical and hospital mergers, for example, have historically been reviewed by the FTC. Telecommunications and defense sector mergers have more frequently gone to the DOJ. This allocation is administrative, not statutory.

Outcomes following investigation

After completing its review, the FTC can take one of four paths: (1) grant early termination of the waiting period, allowing immediate closing; (2) allow the waiting period to expire without action; (3) negotiate a consent order requiring divestitures or behavioral remedies; or (4) seek a preliminary injunction in federal district court to block the transaction pending an administrative proceeding. The FTC's authority to pursue administrative litigation in this context is described further at ftc-administrative-litigation.

Causal relationships or drivers

The HSR framework was enacted in direct response to a pattern in which anticompetitive mergers were consummated before regulators had any opportunity to review them. Once assets are merged and operations integrated, structural remedies become substantially harder to impose — a condition courts and economists have described as the "scrambled eggs" problem.

Threshold adjustments are driven by the FTC's statutory obligation under the HSR Act to revise thresholds annually based on the change in gross national product. This indexing mechanism prevents bracket creep that would otherwise draw an increasing fraction of small transactions into the filing requirement over time.

The frequency of Second Requests correlates with concentration levels in the relevant markets. The FTC's Bureau of Economics constructs quantitative screens — including the Herfindahl-Hirschman Index (HHI) — to identify transactions in markets where post-merger concentration would exceed thresholds flagged in the 2023 Merger Guidelines (DOJ/FTC Merger Guidelines 2023). Under those guidelines, a post-merger HHI above 1,800 in a market where the merger increases the HHI by more than 100 points creates a presumption of competitive harm.

Classification boundaries

Not all transactions involving two businesses trigger HSR filing obligations. The FTC's rules at 16 C.F.R. Part 802 codify a set of exemptions:

• Acquisitions of goods or realty in the ordinary course of business are exempt.
• Acquisitions of foreign assets are exempt unless the U.S. assets or sales exceed $94.9 million (2024 threshold).
• Intraperson transactions — acquisitions where both parties are under common control — are exempt.
• Acquisitions solely for investment purposes, where the acquirer will hold 10% or fewer of the outstanding voting securities and has no intent to participate in formulation, determination, or direction of the issuer's basic business decisions, fall under a passive investor exemption.
• Certain acquisitions by institutional investors of up to 15% of an issuer's voting securities are exempt under 16 C.F.R. § 802.64.

The exemption analysis is structurally distinct from the substantive antitrust analysis. A transaction can be exempt from HSR filing yet still be challenged post-consummation under Section 7 of the Clayton Act. The HSR notification system is a procedural mechanism; it does not confer antitrust clearance.

Tradeoffs and tensions

Compliance burden versus investigative thoroughness

The HSR filing fee structure scales with transaction size. As of 2024, fees range from $30,000 for transactions valued between $119.5 million and $173.3 million, to $2.25 million for transactions valued at $5 billion or more (FTC HSR Filing Fee Schedule 2024). For smaller transactions near the threshold, the filing fee and the cost of preparing the notification can represent a meaningful transaction cost that may deter beneficial deals.

Speed versus depth of review

The 30-day initial waiting period creates time pressure. Agencies must decide whether competitive concerns justify the significant commitment of resources required for a Second Request. This binary choice — let the deal proceed or demand extensive additional information — has been criticized for lacking intermediate options that could allow targeted follow-up without full Second Request burdens.

Negotiated consent versus litigation

Consent orders negotiated as remedies to HSR concerns allow transactions to proceed with structural modifications — typically divestitures of overlapping business lines. Critics argue that divestitures are often insufficient because the divested assets may not constitute a fully competitive business, leaving residual competitive harm. Litigated challenges, by contrast, produce binding court precedent but require the agency to meet a high evidentiary burden and risk complete failure, allowing an unconditioned merger to proceed.

Common misconceptions

Misconception: HSR approval means antitrust clearance.
The expiration of the waiting period without agency action does not constitute a finding that the transaction is lawful under antitrust law. The FTC retains authority to challenge a consummated merger under Section 7 of the Clayton Act. The 2022 case FTC v. Meta Platforms and the ongoing scrutiny of prior acquisitions illustrate that post-consummation challenges remain a live enforcement tool, particularly where the agency believes a prior review was inadequate.

Misconception: Only large companies must file.
The size-of-transaction threshold, not the size of the acquirer, controls whether a filing is required. A company with $10 billion in assets can acquire a startup in a transaction that falls below the $119.5 million threshold without triggering HSR obligations. Conversely, a mid-size company can trigger filing obligations if the deal value alone clears the threshold and both parties separately satisfy the size-of-person tests.

Misconception: The FTC conducts all merger reviews.
The FTC and DOJ Antitrust Division share HSR review jurisdiction. Neither agency has exclusive authority over a transaction class based on statute alone; allocation is determined through interagency coordination. Parties cannot choose which agency reviews their transaction.

Misconception: Early termination is automatic.
Early termination was a routine practice that allowed the waiting period to end before the 30-day clock expired for transactions raising no competitive concerns. The FTC suspended automatic early termination grants in February 2021 (FTC Early Termination Suspension Statement, 2021) as part of a broader policy shift. The practice has not been reinstated as of the last official agency statement on the subject.

Checklist or steps (non-advisory)

The following describes the procedural sequence in the HSR pre-merger notification process as established by statute and FTC rules:

1. Threshold determination — Confirm whether the size-of-transaction and size-of-person tests are met under 16 C.F.R. § 801.
2. Exemption analysis — Evaluate whether any statutory or regulatory exemption under 16 C.F.R. Part 802 applies.
3. Filing preparation — Prepare HSR Notification and Report Forms for both the acquiring and acquired persons; collect required documentary attachments including the 4(c)/4(d) documents (studies, surveys, or analyses prepared by or for officers or directors relating to the acquisition's competitive effects).
4. Fee payment — Submit the applicable filing fee to the FTC based on the transaction value tier.
5. Simultaneous filing — Submit complete filings to both the FTC and the DOJ Antitrust Division on the same day; the waiting period begins upon receipt of both complete filings.
6. Initial waiting period — Observe the 30-day (or 15-day, for cash tender offers) waiting period without closing the transaction.
7. Agency response — Await one of three initial outcomes: early termination grant, waiting period expiration, or issuance of a Second Request.
8. Second Request compliance (if applicable) — Produce responsive documents and data; certify substantial compliance; observe the additional 30-day post-compliance waiting period.
9. Remedy negotiation or litigation (if applicable) — Engage with agency staff regarding potential consent order terms, or respond to any injunction filing in federal court.
10. Closing — Close the transaction only after the applicable waiting period has expired or been terminated, or after obtaining a court ruling permitting consummation.

Reference table or matrix

HSR Threshold and Fee Schedule (FY 2024)

Source: FTC HSR Filing Fee Schedule 2024

Merger Review Outcome Pathways

The complete landscape of FTC enforcement activity — including how merger review intersects with civil investigative demands, consent orders, and broader antitrust enforcement — is covered across the FTC Authority reference site. Detailed treatment of the HSR Act's statutory framework provides additional analysis of the filing rules themselves, while the full scope of FTC antitrust authority is addressed at ftc-antitrust-enforcement.