Mergers in the United States are approved primarily by two federal antitrust agencies: the Federal Trade Commission and the Department of Justice Antitrust Division. Depending on the industry, a deal may also need sign-off from a specialized federal regulator such as the FCC, FERC, or a banking agency, and state attorneys general have independent power to challenge a transaction in court. So the short answer to who approves mergers is that antitrust clearance is the baseline, industry regulators add a second layer where they have jurisdiction, and states sit alongside both.
The FTC and DOJ Antitrust Division
Both agencies enforce the same federal antitrust laws, including the Sherman Act and the Clayton Act.1Federal Trade Commission. The Enforcers Section 7 of the Clayton Act is the operative merger statute; it prohibits any acquisition whose effect “may be substantially to lessen competition, or to tend to create a monopoly” in any market.2Office of the Law Revision Counsel. 15 U.S. Code 18 – Acquisition by One Corporation of Stock of Another
When both agencies could review a deal, they run an internal clearance process to decide who takes it, based on which agency has more experience in the relevant industry. The DOJ typically handles telecommunications and airline mergers. The FTC usually takes healthcare and consumer goods deals.3Justice.gov. Annex 3-B – The Relationship Between Antitrust Agencies and Sectoral Regulators
Neither agency “approves” a merger in the sense of issuing a permit. What they do is decide whether to challenge it. If they find no significant competitive harm, the statutory waiting period runs out and the parties are free to close. If they see a problem they cannot fix through a negotiated remedy, they sue. The FTC can seek a preliminary injunction in federal court or bring the case before its own administrative law judge; the DOJ files directly in federal district court.4Federal Trade Commission. Merger Review
Industry Regulators That Add a Second Layer
For deals in regulated sectors, antitrust clearance is only half of what the companies need. A separate agency applies a separate standard, and a deal can clear DOJ or FTC review and still be blocked or conditioned by the sector regulator.
Telecommunications: The FCC
Any merger that involves transferring FCC-issued licenses (radio, broadcast, or others) needs Federal Communications Commission approval. Under Section 310(d) of the Communications Act, the FCC must find that the transfer serves “the public interest, convenience, and necessity.”5Office of the Law Revision Counsel. 47 U.S. Code 310 – License Ownership Restrictions That test is broader than the antitrust standard. The FCC also looks at whether the deal would enhance (not just avoid harming) competition, promote broadband deployment, and preserve diversity among license holders and information sources.6Federal Communications Commission. Overview of the FCC’s Review of Significant Transactions
Electric Utilities: FERC
Public utility mergers need Federal Energy Regulatory Commission approval under Section 203 of the Federal Power Act. FERC must authorize any merger, consolidation, or acquisition of utility facilities or securities valued above $10 million. Approval requires findings that the deal is consistent with the public interest and will not result in cross-subsidization of non-utility affiliates or the pledging of utility assets for an affiliate’s benefit.7FERC. Mergers and Sections 201 and 203 Transactions FERC must act on a completed application within 180 days, or the application is deemed granted, unless the agency issues a tolling order extending the clock by up to another 180 days.8eCFR. Part 33 Applications Under Federal Power Act Section 203
Banking: OCC, Federal Reserve, or FDIC
Bank mergers require written approval from one of three federal banking regulators, depending on what type of institution results from the combination. The Comptroller of the Currency handles national banks. The Federal Reserve Board handles state member banks. The FDIC handles state nonmember insured banks.9Office of the Law Revision Counsel. 12 U.S. Code 1828 – Regulations Governing Insured Depository Institutions Under the Bank Merger Act, the responsible agency weighs competitive effects, the financial and managerial resources of both institutions, the convenience and needs of the community served, risk to the stability of the U.S. banking system, and the effectiveness of each institution’s anti-money-laundering programs.
State Attorneys General
State attorneys general are not part of the federal review, but they can still stop a merger. The Clayton Act and the Hart-Scott-Rodino Act give them standing to bring antitrust actions in federal court, and most states have their own antitrust statutes providing additional grounds. State AGs frequently join federal cases as co-plaintiffs, but they can also act alone. In the Kroger-Albertsons grocery fight, Washington and Colorado filed separate state-court actions to block the deal while the FTC pursued its own federal challenge.4Federal Trade Commission. Merger Review Clearing federal review does not guarantee freedom from a state-level challenge.
When Federal Review Is Even Triggered
Not every acquisition goes through this machinery. The Hart-Scott-Rodino Antitrust Improvements Act requires reporting to both the FTC and DOJ only when a proposed deal clears certain dollar thresholds, which are adjusted annually for changes in gross national product.10Office of the Law Revision Counsel. 15 U.S.C. 18a – Premerger Notification and Waiting Period For 2026, the thresholds took effect on February 17.
A deal must be reported if it meets three tests: a commerce test (satisfied by nearly all deals), a size-of-transaction test, and, in some cases, a size-of-person test.11Federal Trade Commission. Steps for Determining Whether an HSR Filing Is Required The minimum size-of-transaction threshold for 2026 is $133.9 million. Above $535.5 million, the filing obligation applies regardless of how large the companies are. Between $133.9 million and $535.5 million, at least one party must have total assets or annual net sales of $267.8 million or more, and the other must have at least $26.8 million.12Federal Trade Commission. New HSR Thresholds and Filing Fees for 2026
Deals below the threshold are not subject to the HSR filing regime, but they are not immune from antitrust law. The FTC and DOJ can still investigate and challenge them after the fact under Section 7 of the Clayton Act, and state AGs retain their independent authority.
What the Reviewers Actually Decide
Once a filing is made and the waiting period runs, the reviewing agency reaches one of a few outcomes.
Most deals clear without conditions. If the agency finds no significant competitive harm, the waiting period simply expires, or early termination is granted, and the deal closes on its own terms. The vast majority of reported transactions land here.
Some deals clear with remedies. When the agency identifies problems in specific markets but thinks the overall transaction can be salvaged, it negotiates a fix. Structural remedies are the most common: the parties agree to divest overlapping business units, product lines, or facilities to a third-party buyer approved by the agency, which vets the buyer’s financial capability and its ability to compete effectively in the relevant market.13Federal Trade Commission. A Guide for Potential Buyers – What to Expect During the Divestiture Process Behavioral remedies (firewalls between business units, mandatory licensing) are used less often because they require long-term monitoring.
Some deals get challenged. If the agency concludes the merger would substantially harm competition and no remedy can fix it, it sues. The government must then convince a federal judge that the acquisition is likely to violate Section 7 of the Clayton Act.3Justice.gov. Annex 3-B – The Relationship Between Antitrust Agencies and Sectoral Regulators
And some deals get abandoned. If regulatory signals turn sharply negative, or the remedies demanded would gut the strategic case for the deal, the parties may walk away themselves. That happens more often than outright courtroom losses; the threat of litigation is frequently enough to kill a transaction.
Foreign Regulators for Cross-Border Deals
Clearance in the United States does not carry any weight abroad. Large transactions frequently trigger reviews in multiple countries, and the European Commission, along with authorities in the U.K., China, Japan, and dozens of other jurisdictions, each apply their own filing thresholds, timelines, and substantive standards. A deal cleared in the U.S. can still be blocked or conditioned overseas, and companies pursuing global mergers typically manage parallel filings and, sometimes, separate remedies in each jurisdiction.