Marijuana and Firearms in California:
The Federal-State Conflict

I use marijuana legally under California law. Can I still own firearms?

California was among the first states to legalize medical marijuana (Proposition 215, 1996) and later approved recreational use for adults 21 and older through Proposition 64 in November 2016, codified at Health and Safety Code Sections 11357-11362.45 ^[1]. Despite full state legalization, federal law creates an absolute conflict for firearms owners.

The Federal Prohibition

18 U.S.C. Section 922(g)(3) ^[2] prohibits any person who is an "unlawful user of or addicted to any controlled substance" from possessing firearms or ammunition. Marijuana remains Schedule I under 21 U.S.C. Section 812 ^[3], regardless of state legalization. The base penalty is up to 10 years imprisonment under 18 U.S.C. Section 924(a)(2).

ATF Form 4473, Question 21.e, asks firearms buyers directly whether they are unlawful users of, or addicted to, marijuana or any controlled substance. A bold warning states that marijuana use "remains unlawful under Federal law regardless of whether it has been legalized or decriminalized" in the buyer's state. Answering falsely is a separate federal felony under 18 U.S.C. Section 922(a)(6), carrying up to 10 years imprisonment.

ATF Guidance and the January 2026 Interim Final Rule

ATF's September 2011 Open Letter to all FFLs remains operative: possession of a state-issued medical marijuana card gives a dealer "reasonable cause to believe" the person is an unlawful user, and the dealer may not complete the transfer. In Massachusetts, the medical-use of marijuana program issues registration cards to qualifying patients. A state-issued cannabis registration could, under the ATF interpretation, create a documented trail that a dealer might treat as reasonable cause to believe a person is an unlawful user.

On January 22, 2026, ATF published an Interim Final Rule revising the regulatory definition of "unlawful user of or addicted to any controlled substance" in 27 C.F.R. Section 478.11 ^[4]. The revised definition narrows "unlawful user" to a person who "regularly uses a controlled substance over an extended period of time continuing into the present," without a lawful prescription or in a manner substantially different from prescribed. Critically, the rule establishes that a single recent incident of use or possession is insufficient to classify someone as a prohibited person. ATF described this change as an interim measure pending the Supreme Court's decision in United States v. Hemani. The comment period for the rule closes June 30, 2026 ^[5].

The Ninth Circuit, Hemani, and the March 2026 Oral Arguments

The Ninth Circuit addressed related issues in Wilson v. Lynch, 835 F.3d 1083 (9th Cir. 2016). Importantly, the court did not uphold Section 922(g)(3) on the merits — it dismissed the 922(g)(3) challenge for lack of standing because the plaintiff had not alleged a credible intent to possess firearms while using marijuana. What the Ninth Circuit did uphold on the merits in Wilson was the constitutionality of Section 922(d)(3) (prohibiting dealers from selling to known marijuana users) and the ATF's September 2011 Open Letter under the Second Amendment. However, this was decided before NYSRPA v. Bruen (2022) changed the analytical framework. The Fifth Circuit held Section 922(g)(3) unconstitutional as applied to a marijuana user in United States v. Daniels (5th Cir. 2023).

The Supreme Court granted certiorari in United States v. Hemani (Docket 24-1234). On March 2, 2026, the Court heard oral arguments ^[6]. During arguments, multiple justices appeared skeptical of the government's position defending the constitutionality of Section 922(g)(3) as applied to marijuana users. The questioning focused on the difficulty of defining "habitual user," the distinction between unlawful behavior and dangerous behavior, and whether the historical laws cited by the government were sufficiently analogous under Bruen ^[7]. Legal commentators noted that a narrow ruling -- rather than a complete overturning of Section 922(g)(3) -- appears most likely. A decision is expected by late June 2026.

California State Law

California Penal Code Section 29800 ^[8] prohibits firearms possession by persons convicted of certain felonies, but marijuana use alone is not a disqualifying offense under state law. Health and Safety Code Section 11362.45(a) states that Proposition 64 does not amend or affect federal law. California has not enacted any affirmative protection for firearms owners who use marijuana, unlike some states that have passed "cannabis consumer protection" statutes.

The California DOJ Bureau of Firearms does not cross-reference the MMICP registry with firearms purchase records (DROS). However, a CCW issuing authority retains discretion to consider marijuana use during the "good moral character" evaluation under Penal Code Section 26150 ^[9].

Bottom Line

Settled: Current marijuana users are federally prohibited persons under Section 922(g)(3) regardless of Massachusetts legalization. Lying on Form 4473 is a separate federal felony.

Unsettled: Whether Section 922(g)(3) survives Second Amendment scrutiny under Bruen. Whether a Massachusetts licensing authority may treat marijuana use as a suitability factor under the MGL c.140 §131 suitability standard. Whether the ATF's revised "unlawful user" definition will take final effect.

Watch: The Supreme Court's decision in Hemani (expected June 2026) could reshape this conflict nationwide. If the Court narrows or invalidates Section 922(g)(3) as applied to marijuana users, the ATF's Interim Final Rule, Form 4473 warnings, and the entire federal enforcement framework would require revision.