Federal and state regulations are two parallel systems of legally binding rules that govern businesses and individuals in the United States, and the difference between them comes down to who writes them and where their authority stops. Federal regulations are issued by national agencies under powers Congress draws mainly from the Commerce Clause, and they apply everywhere in the country. State regulations are issued by state agencies under powers reserved to the states by the Tenth Amendment, and they apply only within that state’s borders. The two systems overlap constantly, and when they conflict directly, federal law wins.
Where Each Level’s Authority Comes From
Congress gets most of its rulemaking power from Article I, Section 8 of the Constitution, which lets it regulate commerce “among the several States.”1Congress.gov. Article 1 Section 8 Clause 3 Because almost no modern industry stays inside one state, courts read that language broadly. The Supreme Court held as early as 1905 that Congress can reach even local activity when it forms part of a continuous flow of interstate commerce.2Legal Information Institute. Commerce Clause
Congress rarely writes the technical details itself. It passes a broad statute and hands the specifics to a federal agency. The FAA writes pilot certification and aircraft maintenance rules under Title 14 of the Code of Federal Regulations.3eCFR. 14 CFR Chapter I – Federal Aviation Administration, Department of Transportation The SEC oversees stock markets and brokers under the Securities Exchange Act of 1934.4U.S. Securities and Exchange Commission. The Laws That Govern the Securities Industry The Department of Homeland Security handles border and immigration standards. Each agency operates inside limits Congress set, but the rules it writes carry the force of law.
State authority runs on a different track. The Tenth Amendment reserves to the states every power the Constitution does not give to the federal government or forbid the states from using.5Constitution Annotated. Amdt10.3.2 State Police Power and Tenth Amendment Jurisprudence Courts call this reserved authority the “police power,” meaning states can adopt rules protecting public health, safety, welfare, and morals inside their own borders.
Professional licensing shows the split clearly. Doctors, attorneys, electricians, and barbers all need a state-issued license, and each state’s board sets its own education, exam, and ethics rules. States also control intrastate commerce, including local insurance markets, alcohol sales, and utilities, along with zoning and land use. None of that depends on federal authorization. States run it through their own agencies and their own administrative codes.
How the Rules Actually Get Written
Federal regulations don’t appear out of nowhere. The Administrative Procedure Act sets out a structured process most agencies must follow, and the core of that process is “notice-and-comment” rulemaking.6Office of the Law Revision Counsel. 5 USC 553 – Rule Making It runs in three steps. First, the agency publishes a Notice of Proposed Rulemaking in the Federal Register, explaining what the rule would do, the legal authority behind it, and the exact text. Second, the public gets a comment window, usually 30 to 60 days, though the agency can extend it for complex rules. Third, the agency reviews the comments and publishes a final rule with an explanation of what it accepted, changed, or rejected. The rule normally takes effect at least 30 days after publication.
Once a rule is final, it goes into the Code of Federal Regulations, which sorts every current federal regulation into 50 subject-matter titles.7GovInfo. Code of Federal Regulations If you want to read the actual rule an agency is enforcing against you, the CFR is where you find it.
Rules with an expected annual economic impact of $100 million or more get additional scrutiny. Under Executive Order 12866, the agency must send a detailed cost-benefit analysis to the Office of Information and Regulatory Affairs before the rule can move forward.8US EPA. Summary of Executive Order 12866 – Regulatory Planning and Review States follow their own administrative procedure acts with similar notice-and-comment or public-hearing requirements. Timelines and specific steps vary by state.
When Federal Law Overrides State Law
Where a state rule directly conflicts with a federal one, the federal rule controls. That comes from the Supremacy Clause in Article VI, which declares federal law “the supreme Law of the Land” and binds every state judge to follow it.9Congress.gov. U.S. Constitution – Article VI The Supreme Court reinforced the principle in 1819 in McCulloch v. Maryland, holding that states cannot tax or otherwise obstruct federal government operations.10Justia. McCulloch v. Maryland, 17 U.S. 316 (1819)
The legal term for the override is “preemption,” and it takes three forms.11Congress.gov. Federal Preemption – A Legal Primer Express preemption happens when Congress states outright in the statute that federal law displaces state law on the subject, often with language like “no state may adopt any requirement different from” the federal standard. Field preemption happens when Congress regulates a topic so thoroughly that no room is left for state rules; immigration and nuclear safety are classic examples. Conflict preemption applies when it is physically impossible to comply with both rules at once, or when a state rule would frustrate the purpose Congress meant the federal law to serve.
A working example: if a federal rule requires a specific warning label on a chemical product, a state cannot ban that label. Complying with both would be impossible, so the state rule falls. Preemption is not automatic, though. Courts analyze each conflict on its own, and the party arguing that federal law preempts state law generally has to prove it.
Where the Two Layer On Top of Each Other
Large parts of American regulation are not exclusively federal or exclusively state. Both levels regulate the same subject, and the rules stack. The controlling principle in most shared areas is that state rules can go further than federal ones but cannot drop below the federal floor.
Minimum wage is the cleanest example. The federal Fair Labor Standards Act sets the national floor at $7.25 per hour. Where a state’s minimum wage is higher, employers there must pay the higher rate.12U.S. Department of Labor. Minimum Wage Where a state has no minimum wage or a lower one, the federal floor applies instead.13U.S. Department of Labor. Wages and the Fair Labor Standards Act
Environmental protection follows the same pattern with a more formal partnership. Under the Clean Air Act, the EPA sets National Ambient Air Quality Standards, and each state develops a State Implementation Plan showing how it will meet them.14U.S. Environmental Protection Agency. Basic Information about Air Quality SIPs A state can impose stricter pollution limits than the federal government requires; it cannot go weaker. The EPA reviews and approves each state’s plan, and if a state falls short, the EPA can enforce federal standards directly.
Taxes
Taxation is another shared area, and one that gets complicated fast for businesses. The federal government collects income tax under the Internal Revenue Code, while most states impose their own separate income taxes with different rates, brackets, and deductions. A business operating in multiple states may owe in each one. Remote work has made this harder: in many states, a single employee working from home there can trigger a requirement for the company to register as an employer, withhold state income tax, and file corporate returns in that state. A few states apply a “convenience rule” that taxes an employee’s wages as if the work happened in the employer’s state, even when the employee never sets foot there.
How Courts Review Agency Rules Now
When someone challenges a federal regulation in court, the judge does not simply ask the agency what the rule means and accept the answer. Under the Administrative Procedure Act, courts decide independently whether an agency acted within its legal authority, and they can strike down any rule that is arbitrary, unreasonable, or exceeds what the statute allows.15Office of the Law Revision Counsel. 5 U.S. Code 706 – Scope of Review
The standard changed in 2024. For forty years, courts followed the “Chevron doctrine” from a 1984 Supreme Court case, which told judges to defer to an agency’s interpretation of an ambiguous statute as long as the interpretation was reasonable. Agencies had enormous leverage because whenever a statute was unclear, the agency’s reading usually survived. In June 2024, the Supreme Court overruled Chevron in Loper Bright Enterprises v. Raimondo, holding that the APA “requires courts to exercise their independent judgment in deciding whether an agency has acted within its statutory authority” and that courts “may not defer to an agency interpretation of the law simply because a statute is ambiguous.”16Supreme Court of the United States. Loper Bright Enterprises v. Raimondo (06/28/2024)
The practical effect is significant. Courts can still treat an agency’s reasoning as useful reference, but the judge decides what the statute means. Regulations built on aggressive readings of vague statutory language are more vulnerable than they used to be. The Court noted that prior decisions relying on Chevron do not automatically get overturned, but any new challenge to an agency rule is evaluated under the tougher standard.
Timing rules for challenges also changed. In Corner Post v. Board of Governors, decided in July 2024, the Court held that the six-year statute of limitations for suing under the APA doesn’t start until the challenger is actually injured by the regulation, not when the regulation first took effect.17Supreme Court of the United States. Corner Post, Inc. v. Board of Governors, FRS (07/01/2024) A company formed years after a rule was published can still challenge it, because the company was not injured until it began operating under the rule.
How the Rules Get Enforced
Writing a regulation is only half the work. Enforcement runs through the agencies themselves. At the federal level, agencies like OSHA conduct inspections, issue citations, and impose financial penalties, and can require corrective action by a set deadline.18Occupational Safety and Health Administration. OSHA Penalties
State agencies do the same work for state rules, and many also enforce federal standards through a process called “primacy.” The federal agency delegates enforcement authority to a state on the condition that the state’s program meets or exceeds the federal requirements.19US EPA. Primacy Enforcement Responsibility for Public Water Systems The EPA’s drinking water program works this way. In most states, the inspector at a water treatment facility is a state employee enforcing federal standards.
When an agency finds a violation, it issues a formal notice identifying the rule broken and the evidence. If the business disagrees, it can request an administrative hearing before an administrative law judge, who functions somewhat like a trial judge but sits inside the executive branch rather than the courts. Agencies may also resolve disputes through consent decrees, which are court-approved settlements where the regulated party agrees to stop the disputed conduct and often pay a penalty.20United States Department of Justice. 1-20.000 – Civil Settlement Agreements and Consent Decrees Involving State and Local Governmental Entities Failing to resolve a violation through these channels can lead to license revocation or criminal prosecution.
Filing a lawsuit under the APA is one path to overturn a rule, but not the only one. Congress itself can overturn a federal regulation through the Congressional Review Act, using fast-track procedures in both chambers to pass a joint resolution of disapproval that cannot be filibustered. If the President signs it, the rule is wiped from the books and the agency cannot issue anything substantially the same unless Congress specifically authorizes it.