Cannabis Use and Firearm Ownership: What U.S. Consumers Need to Know

Cannabis laws continue to evolve across the country, but one area remains sharply defined at the federal level: individuals who use marijuana—whether medically or recreationally—face restrictions when it comes to owning or purchasing firearms. For responsible gun owners, understanding where state and federal rules conflict is essential.

Federal Law: 18 U.S.C. § 922(g)(3)

The primary federal statute governing this issue is 18 U.S.C. § 922(g)(3), which prohibits firearm or ammunition possession by anyone who is considered an “unlawful user of or addicted to any controlled substance.” Marijuana remains a Schedule I drug under the federal Controlled Substances Act, meaning the federal government views all non-research marijuana use as unlawful, even in states with legal medical or adult-use programs.

This classification creates a direct legal conflict: a person may be fully compliant with their state’s cannabis rules yet still fall under the federal definition of an unlawful user. Courts have repeatedly upheld that marijuana consumers—medical patients included—fit within this category for firearm-related restrictions under federal law.

ATF Regulations and Form 4473

The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) enforces these rules through licensing requirements and background checks. When purchasing a firearm from a federally licensed dealer, buyers must complete ATF Form 4473. One question asks whether the purchaser is an unlawful user of marijuana or any controlled substance. Beneath the question is clear language stating that marijuana remains illegal under federal law “regardless of whether it has been legalized or decriminalized for medicinal or recreational purposes in the state where you reside.”

Knowingly answering “no” when the buyer regularly uses cannabis can expose them to federal charges, including potential felony penalties for providing false information during a firearm transaction.

Medical Cannabis Patients and Gun Rights

Medical marijuana cardholders face the same restrictions. Federal courts have ruled that the government may prohibit firearm sales to medical cannabis patients because cannabis use falls under the controlled-substance category. Even though many states treat medical cannabis patients like any other lawful consumer, the federal prohibition still applies.

This creates a difficult choice for some chronic pain patients, veterans, and registered medical cannabis users who otherwise follow all state firearm laws. Importantly, the federal rule does not differentiate between THC intake methods—smoking, vaping, edibles, or tinctures all qualify as marijuana use under federal law.

State-Level Trends but No Federal Change Yet

Nearly all states with legal cannabis markets have pushed for greater policy clarity. A handful of states have considered protections for medical patients who own firearms, but none of these measures override the federal prohibition. Unless Congress amends the Gun Control Act or marijuana’s federal scheduling changes, the current restriction remains fully in effect.

Consumer Takeaway

For firearm owners, the safest approach is to understand that cannabis use—legal or not under state law—can trigger federal firearm prohibitions. Staying aware of both sets of regulations remains essential for protecting one’s rights and avoiding unintended violations.