Who Regulates Guns: The Second Amendment, the ATF, and the States
Key takeaways
- The Supreme Court held in 2008 that the Second Amendment protects an individual right to keep a handgun at home, and in 2022 that it protects carrying one in public.
- Since 2022, gun laws must be consistent with the nation's historical tradition of firearm regulation, a test that has produced split rulings in lower courts.
- Federal law licenses dealers, bars certain people from having guns, requires background checks at dealers, and taxes and registers machine guns.
- The ATF enforces federal gun laws, and the FBI runs the background check system.
- States set most rules on carrying, permits, waiting periods, private sales, and which weapons are allowed, so laws vary widely.
- The Supreme Court has agreed to decide whether bans on semiautomatic rifles such as the AR-15 are constitutional.
Gun policy in the United States is shaped by the Constitution, Congress, federal agencies, and especially the states, which write most of the rules people encounter. The Supreme Court's rulings since 2008 have redrawn what governments may do.
This guide explains who does what and lays out the main arguments, without taking sides. Rules change often, so readers should check their own state's laws before buying, carrying, or traveling with a firearm.
The Bureau of Alcohol, Tobacco, Firearms and Explosives licenses dealers and manufacturers, inspects their records, traces guns used in crimes, approves NFA transfers, and investigates gun trafficking. Its rules on items such as pistol braces and gun kits have been fought in court, and in 2025 the Supreme Court upheld its rule treating easily assembled gun kits as firearms. The 2025 administration rolled back several rules, eased penalties for dealers, and began restoring gun rights to some people with past convictions.
States decide most rules on carrying guns, with about 29 now allowing concealed carry without a permit, along with waiting periods, red flag laws that let courts temporarily remove guns from people found dangerous, and bans on certain weapons and magazines in about 10 states. About 46,000 people died from gunshot wounds in 2023, more than half of them suicides. Supporters of more regulation say stronger laws reduce deaths, while gun rights supporters say laws burden law-abiding citizens, do little to stop criminals, and violate a constitutional right.
Licensed dealers must run every buyer through the FBI's background check system or a state system, which screens for felony convictions, domestic violence records, and other disqualifications, usually in minutes. If a check is not finished in three business days, the sale may go through. Federal law does not require checks for private sales, but about 20 states and D.C. do. Gaps in the records states report have contributed to failures.
The National Firearms Act of 1934 taxes and registers machine guns, short-barreled guns, and silencers, and the Gun Control Act of 1968 licenses dealers, limits interstate sales, sets age limits, and bars felons and certain others from having guns. Later laws froze civilian machine gun ownership in 1986, required background checks in 1993, and added checks for buyers under 21 in 2022. A 1994 ban on assault weapons expired in 2004. The tax on suppressors and short-barreled guns fell to zero in 2026.
In New York State Rifle and Pistol Association v. Bruen in 2022 the Court recognized a right to carry a handgun in public and held that gun laws must be consistent with historical tradition. It upheld a ban on guns for people under domestic violence restraining orders in 2024. In June 2026 it unanimously struck down applying the drug user gun ban to an occasional marijuana user, struck down a Hawaii law on guns on private property open to the public, and agreed to decide whether AR-15 bans are constitutional.
The Second Amendment, ratified in 1791, says a well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed. For most of the 20th century courts read it narrowly, but in District of Columbia v. Heller in 2008 the Supreme Court held it protects an individual right to keep a handgun at home for self-defense, and in 2010 applied it to the states. The Court said some limits, such as bans on felons having guns, remain presumptively lawful.
See the full Bill of Rights in the Bill of Rights explained, the ATF and other agencies in federal law enforcement agencies, or state and federal roles in states vs. federal: who does what.