Missouri State Preemption

The Statute

Mo. Rev. Stat. Section 21.750 is Missouri's state preemption statute for firearm regulation. It is one of the strongest preemption statutes in the country. The statute provides that the General Assembly "occupies and preempts the entire field of legislation touching in any way firearms, components, ammunition and supplies to the complete exclusion of any order, ordinance or regulation by any political subdivision of this state." Local firearm ordinances that conflict with state law are void and unenforceable.

What Is Preempted

Section 21.750 preempts all local regulation of:

• The purchase, sale, transfer, ownership, possession, and registration of firearms.
• The carrying of firearms, both concealed and open.
• The discharge of firearms (with limited exceptions for noise, hunting season, and city limits discharge).
• Ammunition and ammunition components.
• Firearm accessories.

Cities, counties, and municipalities may not enact ordinances that:

• Prohibit, restrict, or tax firearm possession beyond what state law provides.
• Require permits, licenses, or registration for firearms or ammunition.
• Restrict the locations where firearms may be carried beyond Section 571.107.
• Impose fees, taxes, or assessments specifically on firearms or ammunition.

The Open Carry Carve-Out

Mo. Rev. Stat. Section 21.750.3 contains a notable carve-out for open carry. The statute allows cities and counties to prohibit open carry by a person who does NOT hold a Missouri CCP. A CCP holder is statutorily exempt from these local open-carry ordinances; a non-CCP-holder constitutional carrier is not.

Cities and counties that have adopted open-carry restrictions for non-CCP holders include:

• City of St. Louis.
• Kansas City.
• Several smaller municipalities.

The Missouri Attorney General has consistently advised that these local ordinances are valid as to non-CCP holders and invalid as to CCP holders. A Missouri carrier in one of these cities should be aware of the local ordinance; a CCP avoids the issue entirely.

Other Limited Carve-Outs

Beyond open carry, Section 21.750 permits local regulation in narrow contexts:

• Discharge of firearms within city limits is regulated by local ordinance (most cities have such ordinances; willful violation can be a misdemeanor).
• Possession of firearms by minors may be regulated by local ordinance in conjunction with state law.
• Possession of firearms in city-owned or city-leased buildings used for non-recreational government functions may be regulated.
• Concealed weapons in courthouses, government meetings, etc. are addressed by Section 571.107 and not separately by local rule.

These carve-outs are limited and have been narrowly construed by Missouri courts.

Private Right of Action

Mo. Rev. Stat. Section 21.750.4 (sometimes referenced as Section 21.750.7 in different compilations) creates a private right of action for any person aggrieved by a local ordinance that violates the preemption. The aggrieved person may sue the political subdivision for declaratory and injunctive relief, plus attorney fees and costs.

This is unusual; most state preemption statutes do not include a private right of action. The Missouri provision has been invoked in litigation against cities that have attempted to enforce conflicting ordinances. The Missouri appellate courts have generally enforced the preemption.

SAPA (Second Amendment Preservation Act)

The Second Amendment Preservation Act (HB 85, 2021), codified at Mo. Rev. Stat. Section 1.410 et seq., was a separate piece of legislation that attempted to bar Missouri law enforcement from cooperating with federal firearms enforcement and imposed civil penalties on local agencies that did so. SAPA was declared facially unconstitutional by the United States District Court for the Western District of Missouri in March 2024 (United States v. Missouri) and affirmed by the Eighth Circuit in 2024. The substantive carry law was not affected by the ruling; only the SAPA mechanism that purported to nullify federal firearms law was struck down.

The preemption statute at Section 21.750 was not affected by the SAPA decision and remains fully in force.

Federal Preemption

Federal firearms law preempts state and local law only where the federal statute expressly or impliedly preempts. The principal federal preemptions:

• The Firearms Owners Protection Act, 18 U.S.C. Section 926A, preempts state law that would prohibit interstate transport of a lawfully possessed firearm meeting the FOPA conditions.
• The Protection of Lawful Commerce in Arms Act, 15 U.S.C. Sections 7901 to 7903, preempts certain civil actions against firearm manufacturers and dealers for the criminal misuse of lawfully sold firearms.

Federal preemption operates independently of state preemption.

What Cities Have Tried

Various Missouri cities have, over the years, attempted to enact firearm ordinances that exceed state law. Some examples:

• Local prohibitions on the discharge of firearms outside city limits or for self-defense (struck down).
• Local prohibitions on carrying firearms in parks (struck down post-2017 SB 656).
• Local registration requirements for handguns (struck down).
• Local "assault weapons" bans (none has survived challenge).
• Local restrictions on the sale of ammunition (struck down).

The pattern has been consistent: when a city attempts to enact a firearm ordinance that exceeds Section 571.107 or otherwise conflicts with state law, the ordinance is challenged in court, the preemption is invoked, and the ordinance is struck down.

What Cities Can Do

Within the preemption framework, cities may:

• Designate specific buildings (City Hall, police stations, recreation centers) as off-limits for concealed carry by posting under Section 571.107.1(13).
• Regulate discharge of firearms within city limits (most cities do).
• Adopt zoning ordinances regulating firearm dealers, ranges, and training facilities, provided the zoning is general and not firearm-specific.
• Enact open-carry ordinances applicable to non-CCP holders under the Section 21.750.3 carve-out.
• Enforce state law through the police power.

Practical Implications

For a Missouri carrier:

• Local firearm ordinances that purport to restrict carry beyond state law are generally unenforceable.
• The exception is the open-carry restriction for non-CCP holders, which is enforceable.
• A CCP is the cleanest way to avoid local-ordinance exposure.
• A carrier who believes a local ordinance is being unlawfully enforced may petition for declaratory and injunctive relief and is entitled to attorney fees and costs.

For a city or county official:

• The preemption is strong. Any new firearm ordinance must be vetted against Section 21.750 before adoption.
• Local prosecutors are not authorized to prosecute violations of conflicting ordinances; doing so risks the private right of action against the prosecuting agency.
• The Missouri Attorney General's office has been actively involved in enforcing the preemption against non-complying cities.

Statutory Authorities

Where to Look Next

• The text of Mo. Rev. Stat. Section 21.750 is published at revisor.mo.gov.
• The Missouri Attorney General publishes preemption guidance and litigation tracking at ago.mo.gov.
• The Missouri Sheriffs' Association publishes guidance on state vs. local authority at mosheriffs.com.
• The Cato Institute and the National Rifle Association Institute for Legislative Action publish state preemption surveys at cato.org and nraila.org.

This section reflects Missouri law as of May 2026. The preemption framework is stable; specific local ordinances change over time and should be verified before relying on local authority.