The Second Amendment: Rights, Limits, and Court Tests

The Second Amendment rights and restrictions that govern firearm ownership in the United States come down to a single principle with clear edges: you have an individual right to keep and carry commonly used firearms for lawful purposes such as self-defense, and every level of government must respect that right, but the government can still bar certain people from possessing guns, restrict where firearms may be carried, and regulate weapons that fall outside ordinary civilian use. Any restriction must fit the nation’s historical tradition of firearm regulation. Three Supreme Court decisions built this framework: District of Columbia v. Heller (2008), McDonald v. City of Chicago (2010), and New York State Rifle & Pistol Association v. Bruen (2022), with United States v. Rahimi (2024) clarifying how the historical test works.

What the Amendment Says

The full text reads: “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.”¹ The militia reference explains why the framers cared about the right, but under current Supreme Court interpretation it does not limit who holds the right. “The right of the people” means individuals, exercised without any connection to militia service.²

An Individual Right That Binds Every Government

For most of American history, the Supreme Court had never squarely answered whether the Second Amendment protects an individual’s right to own a firearm or only a state’s right to maintain a militia. That changed in 2008. In District of Columbia v. Heller, the Court considered a Washington, D.C., handgun ban and ruled 5–4 that the Second Amendment “protects an individual right to possess a firearm unconnected with service in a militia, and to use that arm for traditionally lawful purposes, such as self-defense within the home.”³ Self-defense in the home was identified as the amendment’s core purpose, and handguns, as the most commonly owned firearm for that purpose, received strong protection.

Heller only struck down a federal district’s law. Two years later, McDonald v. City of Chicago extended the ruling to state and local governments through the Fourteenth Amendment, holding that the right to keep and bear arms is “fundamental to our Nation’s particular scheme of ordered liberty.”⁴ After McDonald, no government in the United States — federal, state, county, or city — can disregard the Second Amendment.

Heller also made clear the right is not unlimited. Justice Scalia’s majority opinion identified several categories of regulation it considered “presumptively lawful,” including longstanding bans on possession by felons and the mentally ill, restrictions on carrying in sensitive places like schools and government buildings, and conditions on the commercial sale of firearms.² The Court called the list illustrative, not exhaustive.

Who Cannot Legally Own a Firearm

Federal law prohibits certain categories of people from possessing firearms or ammunition. Under 18 U.S.C. § 922(g), you are barred if you fall into any of these groups:⁵

Anyone convicted of a crime punishable by more than one year in prison.
Anyone who has fled a jurisdiction to avoid prosecution or testimony.
Anyone who is an unlawful user of or addicted to a controlled substance.
Anyone a court has found mentally defective or who has been committed to a mental institution.
Anyone unlawfully in the United States or admitted on a nonimmigrant visa, with limited exceptions.
Anyone dishonorably discharged from the Armed Forces.
Anyone who has renounced U.S. citizenship.
Anyone subject to a qualifying domestic-violence restraining order that includes a finding of credible threat or explicitly prohibits force.
Anyone convicted of a misdemeanor crime of domestic violence.

Violating any of these prohibitions is a federal felony carrying up to 15 years in prison. Heller itself acknowledged that bans on possession by felons and the mentally ill are presumptively constitutional.²

The domestic-violence restraining order prohibition faced a direct constitutional challenge after Bruen. A federal appeals court struck it down, reasoning that the government had not identified a close enough historical analogue for disarming someone under a civil protective order. In June 2024, the Supreme Court reversed 8–1 in United States v. Rahimi, holding that “[w]hen an individual has been found by a court to pose a credible threat to the physical safety of another, that individual may be temporarily disarmed consistent with the Second Amendment.”⁶ The Court drew parallels to colonial-era surety laws and “going armed” statutes.

Which Firearms Are Protected

The Second Amendment does not cover every weapon. Heller adopted what is commonly called the “in common use” test: the amendment protects firearms “typically possessed by law-abiding citizens for lawful purposes.”³ Handguns sit squarely within that protection. Standard rifles and shotguns used for hunting and sport shooting also qualify.

On the other side of the line, “dangerous and unusual weapons” fall outside constitutional protection.² The distinction turns on whether ordinary civilians lawfully own the weapon. Weapons regulated under the National Firearms Act — machine guns, short-barreled shotguns and rifles, silencers, and destructive devices — require registration with the federal government and a $200 transfer tax.⁷ Civilian possession of new machine guns has been banned entirely since 1986, and these restrictions have generally survived legal challenges.

Whether semiautomatic rifles fall on the common-use or dangerous-and-unusual side of the line remains actively contested in federal courts. Several state-level bans exist, and lawsuits challenging them are working through the appeals process.

Where Firearms Can Be Restricted

The Second Amendment protects a right to carry, but not everywhere. “Sensitive places” have been part of Second Amendment law since Heller, which named schools and government buildings as examples. Bruen expanded the list to include courthouses, polling places, and legislative assemblies.⁸ These restrictions rest on the historical tradition of barring weapons from places where government business is conducted or civic gatherings occur.

How far the concept stretches is unsettled. Some states have designated broad categories — parks, restaurants, public transit, private businesses open to the public — as gun-free zones, and those designations face active challenges. The Supreme Court heard argument in Wolford v. Lopez in January 2026, testing whether Hawaii can bar licensed concealed-carry holders from bringing handguns onto private property open to the public unless the owner affirmatively grants permission. A decision is expected by mid-2026.

Federal Buildings and Courthouses

Federal law separately prohibits firearms in federal facilities. Under 18 U.S.C. § 930, knowingly bringing a firearm into a federal facility is punishable by up to one year in prison. Bringing a weapon with intent to commit a crime raises the penalty to up to five years. Federal courthouses carry a separate provision with a penalty of up to two years.⁹ Law enforcement officers on duty and certain authorized federal employees are exempt. You cannot be convicted unless the facility posted notice at public entrances or you had actual knowledge of the restriction.

School Zones

The Gun-Free School Zones Act makes it a federal crime to knowingly possess a firearm within 1,000 feet of a public or private school. Violations carry up to five years in federal prison.¹⁰ Exceptions apply for firearms on private property not part of school grounds, unloaded firearms stored in locked containers in vehicles, possession by someone licensed under state law, and use in a school-approved program. A federal appeals court upheld the 1,000-foot buffer in 2025, though that case involved conduct close to a school rather than testing the outer edge of the zone.

How Courts Test Firearm Laws Today

The framework for judging firearm regulations changed in 2022. Before Bruen, most lower courts weighed the government’s public-safety interest against the burden on the right. Bruen rejected that balancing entirely and replaced it with a two-step test:⁸

Does the Second Amendment’s plain text cover the person’s conduct? If so, the conduct is presumptively protected.
Can the government justify the regulation by showing it is “consistent with the Nation’s historical tradition of firearm regulation”? If not, the law falls.

Judges may not weigh public-safety benefits against the severity of the restriction. The Second Amendment, the Court wrote, “is the very product of an interest balancing by the people,” and courts cannot conduct their own.⁸ A regulation may make sense as policy, but if nothing like it existed in American legal tradition, it fails.

The government does not need a “historical twin” — an identical old law. The modern regulation must be “relevantly similar” to historical predecessors in terms of how much it burdens the right and why.¹¹ Rahimi reinforced this. The Fifth Circuit had read Bruen to demand a near-perfect historical match, and the Supreme Court reversed, faulting the lower court for treating the standard as more rigid than intended. A regulation need only “comport with the principles underlying the Second Amendment.”⁶

Carrying in Public and Concealed-Carry Permits

The specific law Bruen struck down was New York’s concealed-carry licensing scheme, which required applicants to demonstrate “proper cause” — a special need for self-defense beyond what any ordinary person might have. The Court held that the state violated the Constitution “by preventing law-abiding citizens with ordinary self-defense needs from exercising their Second Amendment right to keep and bear arms in public for self-defense.”¹²

Bruen did not eliminate concealed-carry permits. States can still require a permit, run a background check, and mandate training, so long as the criteria are objective. The distinction is between “shall-issue” systems, which grant a permit to anyone who meets defined criteria, and “may-issue” systems, which let an official decide whether the applicant’s reason is good enough. After Bruen, may-issue systems that require you to prove a special need are unconstitutional. States that previously operated under may-issue frameworks, including New York, New Jersey, California, Hawaii, Maryland, and Massachusetts, have had to restructure their licensing regimes.

Background Checks at Purchase

Buying a firearm from a federally licensed dealer requires passing a background check through the National Instant Criminal Background Check System, or NICS. The dealer has you fill out ATF Form 4473 and submits your information, and the system checks whether you fall into any prohibited category under § 922(g).¹³

The check returns proceed, denied, or delayed. If the response is delayed and three business days pass without a final answer, the dealer may complete the transfer but is not required to. For buyers under 21, the waiting period extends to up to 10 business days if the system flags a potentially disqualifying juvenile record.⁵ Federal law requires background checks only for sales through licensed dealers. Private sales between individuals are not covered by a federal check requirement, though many states have enacted their own laws extending the requirement to private transactions.

1
Congress.gov. U.S. Constitution – Second Amendment
2
Justia. District of Columbia v. Heller, 554 U.S. 570 (2008)
3
Library of Congress. District of Columbia v. Heller, 554 U.S. 570
4
Legal Information Institute. McDonald v. City of Chicago
5
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
6
Supreme Court of the United States. United States v. Rahimi (2024)
7
Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act
8
Supreme Court of the United States. New York State Rifle and Pistol Association Inc. v. Bruen
9
Office of the Law Revision Counsel. 18 USC 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities
10
U.S. Department of Justice. Quick Reference to Federal Firearms Laws
11
Constitution Annotated. Amdt2.7 Rahimi and Applying the Second Amendment Bruen Standard
12
Supreme Court of the United States. New York State Rifle and Pistol Association Inc. v. Bruen (2022)
13
Federal Bureau of Investigation. Firearms Checks (NICS)