Federal vs State Law: Which One Applies to You?

Short answer: both usually apply to you at the same time. Federal law comes from Congress and federal agencies and covers the whole country. State law comes from a state's own legislature and agencies and covers that state. When both cover the same subject, you follow both, which in practice often means following whichever sets the higher bar. If the two cannot both be followed, federal law wins, because the Constitution says so.

TL;DR

• Federal law applies in every state. State law applies inside one state. Local law (city and county rules, called ordinances) applies inside that place.
• The Constitution's Supremacy Clause makes valid federal law the top rule when it truly clashes with state law.
• Most of the time there is no clash. Federal law often sets a floor, meaning the lowest standard allowed. A state or city may then go higher.
• "The stricter rule wins" only holds when the federal law leaves room for it. Some federal laws say they replace state rules entirely.
• Check each level for your subject, and write down the date you checked.

Federal vs state law: who makes which law

A statute is a law passed by a legislature. Congress passes federal statutes. Each state legislature passes that state's statutes. Agencies at each level then write regulations, which are detailed rules made under a statute's authority (our guide to statutes and regulations explains the link). Cities and counties pass ordinances.

Why two sets? The Tenth Amendment says that powers the Constitution does not give to the federal government, and does not forbid to the states, stay with the states or the people. So the federal government acts only where the Constitution gives it power, and the states hold the rest.

What the Supremacy Clause says

A clause is one numbered part of the Constitution. Article VI, Clause 2 reads:

"This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding."

You can read the whole text on the National Archives site. In plain words: a federal law made under the powers the Constitution gives Congress outranks a state law that clashes with it, and every state judge must follow the federal one. The word "Pursuance" matters. Congress cannot pass a law outside its powers and expect it to outrank anything.

Preemption in plain words

Preemption means a federal law pushes aside a state law on the same subject. In Arizona v. United States, 567 U.S. 387 (2012), the Supreme Court described three ways it happens:

1. Congress says so in the text of the statute (express preemption).
2. Congress regulates a field so fully that it leaves no room for the states.
3. A state law conflicts with federal law, either because following both is impossible or because the state law blocks what Congress was trying to do.

Here is an express example. A federal retirement-plan law, the Employee Retirement Income Security Act, says its provisions "shall supersede any and all State laws insofar as they may now or hereafter relate to any employee benefit plan." That is section 1144(a) of Title 29 of the United States Code, written 29 U.S.C. § 1144(a).

State rules that relate to those plans generally lose, however strict they are. The statute lists some exceptions in § 1144(b). Congress said so in words.

If Congress closed the door, a stricter state rule can still lose. So which law governs depends on what Congress wrote. You have to read the federal statute for a sentence that says whether states may do more.

When both apply: one minimum wage, three levels

The minimum wage shows the usual pattern.

Federal. The Fair Labor Standards Act sets a minimum wage of $7.25 an hour (29 U.S.C. § 206(a)(1)(C)). Section 218(a) then says how that number relates to other laws:

"No provision of this chapter or of any order thereunder shall excuse noncompliance with any Federal or State law or municipal ordinance establishing a minimum wage higher than the minimum wage established under this chapter..."

That is Congress saying the federal figure is a floor. A higher state or city figure is not displaced. Read the full text on the US Code site.

State. California Labor Code § 1182.12 set the state minimum at $15 an hour and has the Director of Finance adjust it each year for inflation. California's Department of Industrial Relations says, on a page we read October 5, 2026, that effective January 1, 2026 the minimum wage is $16.90 an hour for most employers. Section 1197 of the same code adds that "the payment of a lower wage than the minimum so fixed is unlawful."

Local. The state's wage page says some cities and counties set higher rates, and that "if a local entity (city or county) has adopted a higher minimum wage, employees must be paid the local wage where it is higher than the state or federal minimum wage rates."

So an employer in a California city with its own wage ordinance owes the city's figure. Federal law set the floor, the state raised it, and the city raised it again. We read all of these sources in October 2026. The California figure resets every January, so check the state page before you rely on it.

Where the line falls for a business

Use these steps for any rule you are unsure about.

1. Find the federal rule. Search the US Code (statutes) and the Code of Federal Regulations (agency rules). Our guide to primary law shows what counts as the law itself.
2. Look for the replace-or-allow sentence. Words like "supersede" or "preempt" mean the federal rule may replace state ones. A clause like § 218(a) means states may go higher.
3. Find the state rule for every state where you have staff, customers or property. The 50-state survey guide walks through this.
4. Check cities and counties where you have a site or employees. Whether a city may go beyond its state also depends on state law. California's § 1197 says it does not change the applicability of local minimum wage laws.
5. Record what you found: the source name, the citation, the effective date, the date you read it, and the rule you chose. Our note on citing a statute or regulation shows how.

Agencies also play a part in all this. Our guide to what an administrative agency is explains who writes the rules you will be reading.

What goes wrong

• You treat one level as the whole answer. A payroll setup built on the federal minimum underpays in any place with a higher rate.
• You ignore state rules. Meeting federal requirements does not mean meeting a state's. States often ask for more. Data privacy is a common case: see which states have their own privacy laws.
• You ignore local ordinances. The state's own wage page says employees must be paid the local rate where it is higher.
• You assume the stricter rule always wins. The retirement-plan example shows a federal law that replaces state rules, strict or not.
• You use a summary from the wrong year or the wrong government. Figures change on fixed dates. A page about another state tells you nothing about yours.

This is general information, not legal advice. For a decision with real risk, ask a lawyer licensed in the state that matters. This guide is part of US Law Data: The Complete Guide.

FAQ

What is the main difference between federal and state law? Reach and author. Federal law is written by Congress and federal agencies and applies across the country. State law is written by a state's legislature and agencies and applies inside that state. Most businesses are covered by both.

Which law takes precedence, federal or state? Valid federal law takes precedence when it truly conflicts with state law, because of the Supremacy Clause in Article VI of the Constitution. Many state laws do not conflict. They sit on top of a federal floor.

Can a state law be stricter than federal law? Yes, when the federal law allows it. The Fair Labor Standards Act says a higher state or local minimum wage still has to be followed. Some federal laws say the opposite and replace state rules on their subject.

Do I have to follow both federal and state law? Usually yes. If both cover your activity and you can follow both, you must. Following the stricter one often satisfies both, but confirm that for each rule, because the federal statute may say something different.

What does preemption mean? It means a federal law displaces a state law on the same subject. It can come from express words in the statute, from federal rules so complete that no room is left for states, or from a real conflict between the two.

Can a city make rules that are stricter than state law? Sometimes. It depends on what the state allows. California Labor Code § 1197 says it does not change the applicability of local minimum wage laws to any entity. Other states may handle it differently, so read that state's law.

Where do I find the federal and state version of a rule? Federal statutes are in the United States Code and federal agency rules are in the Code of Federal Regulations. Each state publishes its own code, usually on the legislature's website. Always check the date of the version you read.

If you need US statute and regulation text for a product or a compliance workflow, see the Vaquill AI legal data API.

Priyansh Khodiyar

Co-Founder & CTO

Priyansh leads engineering and AI at Vaquill AI: the pipelines that pull statutes, regulations and court rules from every US jurisdiction's official publisher, and the REST API, MCP server and open dataset that serve them.