The United States regulates insurance differently from many industries with a single dominant federal regulator. Each state has an insurance department or equivalent authority responsible for functions such as licensing, solvency oversight, market conduct and consumer protection. The historical foundation for that structure includes the McCarran-Ferguson Act.
Why Congress passed McCarran-Ferguson
The NAIC traces the law to a change in Supreme Court doctrine. In 1869, Paul v. Virginia treated insurance as outside interstate commerce for Commerce Clause purposes. In 1944, United States v. South-Eastern Underwriters Association concluded that insurance transactions could be interstate commerce and therefore subject to federal power. Congress responded in 1945 with the McCarran-Ferguson Act to preserve state authority over insurance regulation and taxation.
What the act does
The law declares that continued state regulation and taxation of the business of insurance is in the public interest. In simplified terms, a federal statute is not normally read to invalidate, impair or supersede a state law enacted to regulate the business of insurance unless the federal law specifically relates to insurance. Courts have developed substantial case law around what counts as the “business of insurance” and when state law is protected.
Does the federal government regulate insurance at all?
Yes. McCarran-Ferguson does not create a federal-free zone. Congress has enacted laws that specifically affect insurance and financial services, and federal agencies have roles in areas such as terrorism risk, health coverage, sanctions, securities, consumer finance, taxation and international insurance policy. State and federal authority can therefore overlap.
| Level | Examples of insurance-related roles |
|---|---|
| State insurance regulators | Company and producer licensing, financial examinations, solvency oversight, product/rate review where applicable, market conduct and consumer complaints. |
| NAIC | Coordination, model laws and regulations, financial data and accreditation support; it is not itself a federal regulator. |
| Federal government | Specific statutory programs and cross-industry laws that apply to insurance in defined circumstances. |
What about antitrust law?
McCarran-Ferguson also addresses the interaction between insurance and federal antitrust law. The details are legally complex and have been changed by later legislation in particular areas. It is inaccurate to summarize the act as a blanket antitrust exemption for every insurance activity. Businesses should rely on current legal authority for a specific conduct question.
Why consumers see different insurance rules by state
State-based regulation helps explain why auto minimum liability limits, workers’ compensation systems, homeowners forms, rate-filing rules, guaranty-association protections and producer licensing requirements can differ across state lines. National insurers often operate through many state-specific approvals and legal entities rather than one uniform federal insurance license.
What McCarran-Ferguson does not mean
- It does not mean every insurance rule is identical within a state.
- It does not mean the NAIC is a federal agency.
- It does not prevent Congress from passing federal laws that specifically address insurance.
- It does not make every insurance company exempt from all federal regulation.
- It does not answer whether a particular policy claim is covered; that depends on the contract and applicable law.
Why the act still matters
The NAIC’s current insurance-topic guidance continues to describe McCarran-Ferguson as a foundational element of the U.S. state-based system. Debates about the balance of state and federal roles continue, but the practical reality for consumers and insurers is that state insurance departments remain central to licensing, solvency and market regulation.
Frequently asked questions
Is insurance regulated by the states or the federal government?
Primarily by the states for core insurance regulation, with important federal laws and programs applying in specific areas.
Is the NAIC a government regulator?
The NAIC is an organization of state insurance regulators. Regulatory authority comes from the individual states and jurisdictions, not from the NAIC acting as a federal agency.
Did McCarran-Ferguson create state insurance departments?
No. State insurance regulation existed before 1945; the act preserved and clarified the federal-state framework after the 1944 Supreme Court decision.
Can Congress override state insurance law?
Congress can legislate in this area. Whether a federal statute displaces a state insurance law depends on the text, purpose and legal framework of the statutes involved.
Sources & further reading
Reviewed October 2, 2026. This is a general regulatory explainer, not legal advice; federal and state insurance law can change and specific questions require current legal authority.
