In Missouri, you have to be at least 18 to buy a handgun in a private sale and traditionally 21 to buy one from a licensed dealer under federal law. Missouri itself sets no state age above the federal floor, and 18 is also the minimum age to legally possess a handgun. The federal 21-year-old rule for dealer sales is currently being challenged in court, so that piece of the answer could shift.
Buying From a Licensed Dealer
The Gun Control Act of 1968 set 21 as the minimum age to buy a handgun from a federally licensed firearms dealer. That covers every gun store, pawn shop, and sporting goods retailer holding a Federal Firearms License.
In January 2025, the Fifth Circuit Court of Appeals struck down the federal statutes barring licensed dealers from selling handguns to 18-to-20-year-olds, ruling the ban violates the Second Amendment. As of early 2026, the U.S. Supreme Court has signaled it will take up a related gun-rights case. Until the Supreme Court rules, whether an 18-year-old can walk into a dealer and buy a handgun depends on the federal circuit and on whether the dealer is willing to rely on the Fifth Circuit’s decision. Many dealers have kept the 21 rule in place while the law settles.
If you’re age-eligible, the purchase itself is straightforward in Missouri. You fill out ATF Form 4473, the dealer runs a background check through the National Instant Criminal Background Check System, and if the response is “proceed,” the sale can close. You’ll need a valid government-issued photo ID showing your name, residential address, and date of birth; a driver’s license or state ID is the usual document. A Social Security card doesn’t work because it has no photo or address, though you can combine government-issued documents if no single one covers all three items.1Bureau of Alcohol, Tobacco, Firearms and Explosives. Firearms Transaction Record – ATF Form 4473
Missouri imposes no waiting period and requires no separate purchase permit. If your background check clears, you leave with the handgun the same day.
Buying in a Private Sale
The minimum age drops to 18 for a private sale between two Missouri residents. A private sale is any transaction where neither party holds a federal firearms license, such as buying from a friend, a neighbor, or a private seller at a gun show. No background check is required, and no state form or permit is involved.
Missouri law makes it a crime to recklessly sell or give any firearm to someone under 18 without permission from that person’s parent or legal guardian, and unlawful transfer to a minor is a Class A misdemeanor.2Missouri Revisor of Statutes. Missouri Code 571.060 – Unlawful Transfer of Weapons, Penalty Because there’s no mandated background check for private transfers, the responsibility to avoid selling to a prohibited buyer falls on the seller. Knowingly selling to a prohibited person is still a crime under state and federal law, so cautious sellers often ask for ID or ask the buyer to arrange a voluntary background check through a local dealer.
Possession vs. Purchase at 18
Buying a handgun and possessing one are separate legal questions in Missouri. Lawful possession begins at 18. That creates a practical gap for 18-to-20-year-olds who can’t yet buy from a dealer under the federal rule: they can still legally own a handgun they received as a gift from a family member, inherited, or bought through a private sale.
Anyone under 18 is prohibited from knowingly possessing a handgun or handgun ammunition, with narrow exceptions. A minor may temporarily possess a handgun at a shooting range or while under the direct supervision of a parent, guardian, or approved adult, and those exceptions require prior written consent from the parent or guardian.
Buying a Handgun in Another State
If you find a handgun for sale in another state, you can’t buy it over the counter and take it home. Federal law bars licensed dealers from selling a handgun directly to a resident of another state. The out-of-state dealer has to ship the firearm to a licensed dealer in Missouri, where you complete Form 4473 and the background check as if you were buying locally.3ATF eRegulations. 27 CFR 478.29 – Out-of-State Acquisition of Firearms by Nonlicensees Over-the-counter out-of-state purchases are allowed for rifles and shotguns, but never for handguns.
The receiving Missouri dealer charges a transfer fee for the paperwork and background check, typically $10 to $50. Private handgun sales across state lines are also prohibited without going through a licensed dealer, so you can’t legally buy a handgun from a private seller in Kansas and drive it home.
Who Can’t Buy Regardless of Age
Meeting the age requirement isn’t enough on its own. Federal law bars several categories of people from buying or possessing any firearm, whether through a dealer or a private sale:
- Anyone convicted of a felony (any crime punishable by more than one year in prison)
- Anyone convicted of misdemeanor domestic violence
- Anyone subject to a domestic violence restraining order
- Anyone dishonorably discharged from the military
- Anyone adjudicated as mentally incompetent or committed to a mental institution
- Unlawful users of controlled substances
- Fugitives from justice
- Unlawful noncitizens and anyone who has renounced U.S. citizenship
These prohibitions come from the Gun Control Act and apply in every state.4Bureau of Alcohol, Tobacco, Firearms and Explosives. Identify Prohibited Persons
Buying a handgun for someone in a prohibited category, known as a straw purchase, carries up to 25 years in federal prison and a fine equal to twice the gross proceeds of the offense under the Bipartisan Safer Communities Act.5Federal Register. Bipartisan Safer Communities Act Conforming Regulations Form 4473 contains a specific question aimed at catching it.
Carrying After You Buy
Missouri has been a permitless carry state since 2017. If you’re at least 19 and not otherwise prohibited from owning a firearm, you can carry a concealed handgun without a permit. An 18-year-old who lawfully owns a handgun generally cannot carry it concealed in public without a permit.
The state still issues concealed carry permits for people who want the reciprocity benefits when traveling to other states or who want to streamline dealer purchases at home.