Gun laws by state sit on top of a federal floor that applies everywhere, and the gap between the floor and what any given state actually requires is wide enough that a fully law-abiding owner in one state can commit a felony by driving across a border without changing anything else. Federal law decides who is allowed to own a firearm, requires background checks at licensed dealers, and bans guns in federal buildings. Almost everything else, including whether private sales are checked, whether you need a permit to carry, what kind of rifle or magazine you can own, and whether you have to retreat before defending yourself, is set by the state you happen to be standing in.
The Federal Floor: Who Cannot Own a Gun
Before state rules come into play, 18 U.S.C. § 922(g) permanently or conditionally bars nine categories of people from possessing firearms or ammunition anywhere in the country:1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
- Anyone convicted of a crime punishable by more than one year in prison, regardless of the sentence actually served.
- Fugitives from justice.
- Current users of controlled substances, including marijuana users in states where marijuana is legal.
- Anyone a court has found mentally unfit or who has been involuntarily committed.
- People unlawfully in the country or admitted on most nonimmigrant visas.
- Anyone dishonorably discharged from the military.
- Former citizens who have renounced U.S. citizenship.
- People subject to a qualifying domestic violence protective order involving an intimate partner or child.
- Anyone convicted of a misdemeanor crime of domestic violence.
A licensed dealer runs every buyer through the FBI’s National Instant Criminal Background Check System (NICS) to catch these disqualifying factors.2Federal Bureau of Investigation. Firearms Checks (NICS) A clean result clears the sale immediately. A “delayed” result lets the sale go through after three business days unless a final denial arrives; buyers under 21 face an enhanced review that can add up to ten business days for juvenile records.1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts The federal check requirement covers licensed-dealer sales only, and that is where state divergence begins.
Buying a Gun: What Changes at the State Line
Background Checks on Private Sales
Roughly 20 states and the District of Columbia require a NICS check on every firearm transfer, including private sales between individuals. In those states, a private buyer and seller meet at a licensed dealer to run the transaction. The remaining states allow private sales without any check, so a buyer can walk away from a neighbor or a gun show table with a firearm and no government screening.
Permit-to-Purchase
A smaller group of states requires a permit before you can even walk into a gun store. Applicants apply through local law enforcement, submit fingerprints, and undergo an investigation that goes beyond a standard NICS check. Processing runs anywhere from 30 days to several months, and the permit itself is often valid for only one year or a single purchase.
Waiting Periods
Ten states and the District of Columbia require a mandatory wait, ranging from three to fourteen days, between the completion of a purchase and the actual handoff of the firearm. Four additional states impose waiting periods only on specific categories such as handguns. The intent is a cooling-off period that can interrupt impulsive violence or self-harm. Dealers who release a firearm early risk losing their state license.
Age Requirements
Federal law sets 18 as the minimum for buying a rifle or shotgun from a licensed dealer and 21 for a handgun.1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Several states have raised the minimum to 21 for all firearms, usually with exceptions for active-duty military and law enforcement. Some states also set minimum ages for private sales, an area where federal law is largely silent.
What You Can Legally Own
Assault Weapon Bans
About ten states ban categories of semi-automatic firearms defined by feature tests. A typical ban targets a semi-automatic action combined with accessories such as a detachable magazine plus a pistol grip, a folding or telescoping stock, a flash suppressor, or a threaded barrel. Some states use a named-model list instead of a feature test. In the other states, any firearm legal under federal law can be purchased.
When a state enacts a new ban, existing owners are usually given a registration grace period. Missing the deadline can convert a legal firearm into a criminal possession.
Magazine Capacity Limits
States with hardware restrictions frequently cap detachable magazine capacity, most commonly at 10 or 15 rounds. Possessing an over-capacity magazine in a limit state can support criminal charges even if the magazine was legal where it was purchased. Owners who move into a restricted state generally have to permanently modify their magazines, sell them out of state, or surrender them.
Ammunition
Armor-piercing ammunition is restricted federally. A handful of states go further and prohibit incendiary rounds or, in very limited cases, certain hollow-point designs. Selling or transporting prohibited ammunition can lead to misdemeanor or felony charges depending on quantity.
Privately Made Firearms
Under current federal rules, an individual who builds a firearm at home from a kit or a 3D printer for personal use does not have to serialize or register it, provided they are not in the business of manufacturing for sale. If a privately made firearm passes through a licensed dealer, the dealer must mark it with a serial number within seven days or before selling it, whichever comes first.3Bureau of Alcohol, Tobacco, Firearms and Explosives. Privately Made Firearms Several states have gone further, requiring serial numbers on all privately made firearms, banning unserialized parts kits, or both. Laws in this area are changing faster than in almost any other part of the gun debate.
Handgun Rosters
A small number of states maintain approved rosters of handgun models that can be sold at retail within their borders. Handguns must pass state-certified safety testing, and manufacturers pay an annual fee to stay listed. Some roster states also require features like loaded-chamber indicators or microstamping, which etches a unique identifier onto spent casings. Because few manufacturers have adopted microstamping, new models on these rosters have grown scarce, and a handgun widely available elsewhere may be effectively unavailable in a roster state.
Carrying in Public
Constitutional Carry
Twenty-nine states allow adults to carry a concealed handgun without any permit. The minimum age is typically 21, though a few states set it at 18. No application, training course, or fee is required as long as the person is not otherwise prohibited under federal or state law. Location-based restrictions on schools, government buildings, courthouses, and other designated areas still apply.
Shall-Issue Permits
In shall-issue states, the government must grant a concealed carry permit to anyone who meets objective, published criteria, typically age 21, a passing background check, and a certified training course. Because the standards are set by statute, law enforcement has no discretion to deny a qualified applicant. Many residents of constitutional carry states still get a permit for reciprocity with other states, which only applies to permit holders.
May-Issue After Bruen
A few states historically let law enforcement deny permits even to applicants who met every safety and background requirement, unless the applicant could show a specific documented need for self-defense. In 2022, the Supreme Court struck down New York’s “proper cause” standard in New York State Rifle & Pistol Association v. Bruen, holding that it violated the Second and Fourteenth Amendments by preventing law-abiding citizens with ordinary self-defense needs from carrying in public.4Supreme Court of the United States. New York State Rifle and Pistol Association Inc. v. Bruen Former may-issue states have moved to more objective systems, though several responded by adding extensive training requirements and expanding the list of locations where carrying is banned.
Training and Fees
Required training ranges from a four-hour classroom-only session to an 18-hour combined classroom and live-fire course, covering legal use of force, de-escalation, and safe storage. Course costs run about $25 to $350, with application fees on top ranging from about $40 to over $400. The spread makes a carry permit far more accessible in some states than others.
Non-Resident Permits
Some states issue permits to out-of-state residents, which frequent travelers use to extend their reciprocity coverage. Non-resident permits often cost more and may require a trip to the issuing state for fingerprinting. Not every state offers them, and a few reserve the right to carry to their own residents.
Open Carry
Open carry is treated inconsistently. Some states allow it without any permit, others require the same license as concealed carry, and a few prohibit it outright in urban areas while permitting it in wilderness settings. Even where it is legal, it frequently prompts calls to police.
Where You Cannot Carry, Regardless of Your Permit
Federal law bans firearms in any building owned or leased by the federal government where federal employees regularly work. Knowingly bringing a firearm into a federal facility carries up to one year in prison; if the weapon is intended for use in a crime, up to five years.5Office of the Law Revision Counsel. 18 USC 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities Federal courthouses carry a separate two-year penalty. Post offices have their own regulation banning firearms on postal property entirely, openly or concealed.6United States Postal Service. Poster 158 – Possession of Firearms and Other Dangerous Weapons on Postal Service Property A state carry permit does not override any of this, so a lawful carrier who walks into a VA hospital, Social Security office, or post office is committing a federal offense.
States add their own sensitive-location lists. Common entries include schools and school zones, government buildings, polling places, bars and establishments that primarily serve alcohol, hospitals, houses of worship, and public transit. After Bruen, several states expanded these lists significantly. Violations can trigger permit revocation, fines, and criminal charges.
Self-Defense: Same Act, Different Outcome
Castle Doctrine
Roughly 45 states recognize some version of the castle doctrine, which removes the duty to retreat before using force in self-defense inside your home. Many states pair this with a legal presumption that anyone who unlawfully enters your home intends serious harm, making the use of deadly force easier to justify. Some states extend the protection to vehicles and workplaces; others limit it to the home.
Stand Your Ground
About 27 states have stand your ground laws that remove the duty to retreat even outside the home. If you are legally present somewhere and reasonably believe deadly force is necessary to prevent death or serious injury, you can use it without first attempting to escape. Some of these states also provide civil immunity when the use of force is found justified.
Duty to Retreat
About a dozen states impose the opposite rule: outside your home, if you can safely walk away, you must. Failing to retreat when it was possible can turn an otherwise justified shooting into a criminal act. Castle doctrine still applies inside the home in most of these states, so the difference primarily affects public confrontations. The same defensive act can be a justified shooting or a murder charge depending entirely on which side of a state border it happened.
Traveling With a Firearm
Reciprocity
Reciprocity is an agreement between states to honor each other’s concealed carry permits. If your home state has reciprocity with your destination, you can carry on your existing permit. Agreements are not standardized and can change through legislation or executive action. No federal reciprocity law exists as of 2026, though proposals have been introduced repeatedly in Congress.7United States Congress. S.65 – Constitutional Concealed Carry Reciprocity Act of 2025 Checking a current reciprocity map before each trip is the only reliable way to confirm your permit is valid at your destination.
Driving Through a State Where You Cannot Carry
When you are passing through a state where you have no carry permit and no reciprocity, 18 U.S.C. § 926A gives limited protection. You may transport a firearm through any state provided it is legal at your point of origin and your destination, the firearm is unloaded, and neither the gun nor the ammunition is readily accessible from the passenger compartment.8Office of the Law Revision Counsel. 18 USC 926A – Interstate Transportation of Firearms In a vehicle without a separate trunk, the firearm must be in a locked container other than the glove compartment or console.
The protection is narrower than most gun owners realize. It covers transit only. Overnight stops, errands, or extended stays in a state where the firearm is otherwise illegal end the federal shield and put you under local law. A locked glove box does not qualify as a locked container under the statute, and treating it as one has produced criminal charges in strict-transport states.
Magazines in Transit
The § 926A protection covers “a firearm” and “ammunition.” It does not clearly extend to accessories such as magazines. Courts have allowed arrest and criminal charges for carrying a magazine that exceeds a state’s capacity limit even while passing through without stopping. If your route crosses a state with a 10-round cap, the safe course is to leave non-compliant magazines at home or ship them separately.
Duty to Inform During Traffic Stops
About a dozen states and the District of Columbia require you to tell a police officer immediately, without waiting to be asked, that you have a firearm in the vehicle during any law enforcement encounter. Other states only require disclosure if the officer asks. Failing to inform in a duty-to-inform state can lead to seizure of the firearm, permit suspension, and separate criminal charges. Volunteering the information is the safer choice when traveling in unfamiliar states.
Red Flag Laws
Twenty-two states and the District of Columbia have extreme risk protection order laws, which let a court temporarily remove firearms from someone who shows signs of being a danger to themselves or others. The proceedings are civil, not criminal, so the order itself does not create a criminal record.
An authorized petitioner files for the order. In some states only law enforcement can petition; others allow family members, household members, medical professionals, or school officials. The petition must present evidence of recent threatening behavior, such as explicit threats of violence or acts of self-harm. If the judge finds the risk immediate, a temporary “ex parte” order can issue the same day, without the subject present.
The temporary order typically lasts one to two weeks, followed by a full hearing where the subject can appear and present evidence. If extended, the order usually lasts up to one year, under a “clear and convincing evidence” standard. Firearms are held by law enforcement or a licensed third party during the order. Once it expires, the subject can petition for return of the firearms after passing a background check and showing they no longer pose a risk. Most red flag statutes include penalties for filing knowingly false or malicious petitions.
Storage Requirements and Lost or Stolen Reporting
Thirty-five states and the District of Columbia have some form of child access prevention law. These generally impose criminal liability on an owner who leaves a firearm accessible to a minor, especially when the child gains access and causes injury. Penalties range from a misdemeanor to a felony where serious injury or death results. Common exemptions cover firearms stored in a locked container or fitted with a trigger lock, and cases where the child accessed the firearm through illegal entry.
Federal law requires every licensed dealer to include a secure storage or safety device with each handgun sold. Some states go further, mandating that all firearms in a home be stored unloaded in a locked container when not in active use, with ammunition stored separately. Penalties can apply even when no child ever touches the gun.
About 17 states and the District of Columbia require gun owners to report lost or stolen firearms to law enforcement within a set window, typically 24 hours to ten days after discovering the loss. Failing to report can bring fines or criminal charges. The laws are designed to prevent a common evasion tactic: selling a gun illegally, then claiming theft if it surfaces at a crime scene. Even in states without a reporting requirement, prompt police reports protect owners whose stolen firearms are later used in crimes.
State Preemption and Local Ordinances
One of the least visible variations is whether a state lets cities and counties pass their own firearm rules. Most states have preemption laws that reserve firearm regulation to the state legislature, producing a uniform rule set within the state. In states without strong preemption, large cities have enacted regulations substantially stricter than surrounding state law, including bans on specific firearm types, local permit requirements layered on top of state permits, and restrictions on discharge and storage within city limits. A resident can be fully compliant with state law and violating local ordinance the moment they cross into a city. Municipal codes are also harder to research than state statutes, because they are not always available in searchable databases.
Some states have gone the other direction with punitive preemption, letting individuals sue local governments that pass unauthorized ordinances and recover attorney’s fees when they win. A few impose personal fines on local officials who vote for such ordinances, or allow their removal from office. This tension between local control and statewide uniformity is one of the most active areas of firearms litigation, and it determines whether a gun owner can rely on knowing one set of rules or has to check every municipality on the route.