Colorado gun laws are among the strictest in the western United States. If you want to buy, carry, or keep a firearm in the state, you’re operating under universal background checks, a three-day waiting period, a minimum age of 21, a ban on large-capacity magazines, a prohibition on unserialized firearms, safe storage rules, a red flag law, and — starting August 1, 2026 — a broad ban on many semiautomatic firearms. Local governments can layer additional restrictions on top.
Buying a Firearm in Colorado
Every firearm sale requires a background check. That’s true whether you’re buying from a licensed dealer or from a neighbor. Private sellers have to route the transaction through a licensed dealer, who runs the check through the Colorado Bureau of Investigation. Skipping this step is a class 1 misdemeanor, punishable by up to 364 days in jail, a fine up to $1,000, and a two-year ban on possessing firearms.1Justia. Colorado Code 18-12-112 – Private Firearms Transfers – Sale and Purchase – Background Check Required – Penalty – Definitions2FindLaw. Colorado Code 18-1.3-501 – Misdemeanors Classified – Penalties
A clean background check doesn’t get you same-day possession. The seller cannot transfer the firearm until at least three days after the check is initiated, or until the check comes back approved, whichever is later.3Justia. Colorado Code 18-12-115 – Waiting Period for Firearms Sales – Background Check Required – Penalty – Exceptions
The minimum purchase age is 21 for all firearms, not just handguns. Licensed dealers cannot sell to anyone younger, and it’s separately unlawful for anyone under 21 to purchase. Narrow exceptions apply to active-duty military and on-duty peace officers.4Colorado Public Law. Colorado Code 18-12-112.5 – Firearms Transfers by Licensed Dealers
Banned Firearms and Accessories
Large-Capacity Magazines
Colorado bans the sale, transfer, and possession of large-capacity magazines. That means any detachable magazine that holds more than 15 rounds, or a tubular shotgun magazine longer than 28 inches. A first violation is a class 2 misdemeanor with up to 120 days in jail and a $750 fine. A second offense becomes a class 1 misdemeanor, and possessing a banned magazine during a felony or crime of violence is a class 6 felony.5Colorado Bureau of Investigation. Colorado Code 18-12-302 – Large-Capacity Magazines Prohibited – Penalties – Exceptions
Ghost Guns
Since 2024, it has been illegal to possess, sell, or transfer any firearm, frame, or receiver without a serial number imprinted by a federally licensed dealer. The ban reaches unfinished frames and receivers — the core components used to build homemade guns. Antique firearms manufactured before October 22, 1968, and permanently inoperable weapons are excepted.6Justia. Colorado Code 18-12-111.5 – Unserialized Firearms and Firearm Components
The 2026 Semiautomatic Ban
SB25-003, signed in April 2025, bans the manufacture, sale, purchase, and transfer of many semiautomatic firearms starting August 1, 2026. The law covers semiautomatic rifles and shotguns that accept detachable magazines, as well as gas-operated semiautomatic handguns with detachable magazines. Specific models and firearm types are excluded from the statutory definition.7Colorado General Assembly. SB25-003 Semiautomatic Firearms and Rapid-Fire Devices
Transactions involving law enforcement, the military, gunsmiths, museums, and historical societies are exempt. The law also carves out an exception for individuals who have completed a certified hunter education course and a firearms safety course within the previous five years. A first violation is a class 2 misdemeanor; a second or subsequent offense is a class 6 felony, which brings a permanent ban on firearm possession.7Colorado General Assembly. SB25-003 Semiautomatic Firearms and Rapid-Fire Devices
Concealed and Open Carry
Colorado is a shall-issue state for concealed handgun permits. The county sheriff must issue a permit to any applicant who meets the statutory criteria: Colorado residency, age 21 or older, and documented handgun competence through a certified training course completed within the previous ten years.8Justia. Colorado Code 18-12-203 – Criteria for Obtaining a Permit Applicants go through a fingerprint-based background check at both the state and federal level, and pay processing fees to the CBI and to their sheriff’s office.9Colorado Bureau of Investigation. Concealed Handgun Permit (CHP)
Colorado honors concealed carry permits from other reciprocal states, but only if the permit holder is a resident of the issuing state, is at least 21, and carries a valid photo ID from that state. Colorado residents cannot use an out-of-state nonresident permit — they must carry under a Colorado-issued permit.10Justia. Colorado Code 18-12-213 – Reciprocity The CBI maintains the current reciprocity list.11Colorado Bureau of Investigation. Concealed Handgun Permit (CHP) Reciprocity
Open carry isn’t prohibited at the state level, but the state has left that decision to local governments. Denver and Boulder are among the cities that ban open carry within their limits, so verify local rules before carrying openly.
Where Concealed Carry Is Off-Limits
A permit doesn’t cover every location. State law prohibits carrying in a list of sensitive places:
- K-12 school property and buildings, public or private.
- College and university grounds and buildings, including the Auraria Higher Education Center.
- Licensed child care facilities.
- Government buildings with permanent security personnel and electronic screening at every entrance.
- Polling places, ballot drop boxes, and central count facilities.
- Any location where federal law prohibits carrying.
- Any location where a local ordinance prohibits concealed carry.
These restrictions sit in the same statute that grants permit authority, so every permit holder is on notice by law.12Justia. Colorado Code 18-12-214 – Authority Granted by Permit – Carrying Restrictions – Local Authority Local governments can add more restricted areas within their jurisdictions.
Safe Storage and Reporting Lost or Stolen Firearms
Firearms must be securely stored when not in use to keep them away from unsupervised minors and other unauthorized people. Compliance means the firearm is on your person, locked in a gun safe or secure container, or fitted with a locking device, with no juvenile or prohibited household member having access to the key or combination. A storage violation that gives a minor access, or that gives access to a household member barred from possessing firearms, is a class 2 misdemeanor.13Justia. Colorado Code 18-12-114 – Secure Firearm Storage Required – Penalty
A lost or stolen firearm has to be reported to law enforcement within five days of discovering the loss. The first failure to report is a civil infraction with a $25 fine. A second or subsequent failure is a misdemeanor with a fine up to $500.14Colorado General Assembly. SB21-078 Lost or Stolen Firearms
Extreme Risk Protection Orders
Colorado’s red flag law lets a court temporarily remove firearms from someone who poses a significant risk of harm to themselves or others. A family member, household member, community member, or law enforcement officer can file the petition. If a judge finds an immediate risk, a temporary order can issue the same day, even without notice to the respondent, and stays in place until a full hearing scheduled within 14 days.15Justia. Colorado Code 13-14.5-103 – Temporary Extreme Risk Protection Order
At the full hearing the petitioner must prove by clear and convincing evidence that the respondent poses a significant risk. A granted order lasts 364 days. The respondent must surrender all firearms and any concealed carry permit to law enforcement or a licensed dealer. Antique firearms and relics may go to an eligible family member who doesn’t live with the respondent.16Colorado General Assembly. HB19-1177 Extreme Risk Protection Orders
The respondent can file one motion during the 364 days asking the court to terminate the order early, but the burden is on the respondent to show by clear and convincing evidence that they no longer pose a significant risk. When the order expires or is terminated, surrendered firearms must be returned within three days of a request.16Colorado General Assembly. HB19-1177 Extreme Risk Protection Orders
Who Cannot Legally Possess a Firearm
Federal law prohibits firearm possession by anyone convicted of a crime punishable by more than a year of imprisonment, anyone subject to a domestic violence restraining order, and anyone convicted of a misdemeanor crime of domestic violence.17Colorado Bureau of Investigation. State and Federal Firearm Prohibitors
Colorado adds more categories. A conviction for violating the state’s background check requirement carries a two-year loss of firearm rights. Juveniles adjudicated delinquent for what would be a felony as an adult are prohibited for ten years. Since 2021, convictions for certain misdemeanors — including third-degree assault, stalking-related protection order violations, harassment, bias-motivated crimes, and animal cruelty — trigger a five-year prohibition on firearm transfers through the CBI’s background check system.17Colorado Bureau of Investigation. State and Federal Firearm Prohibitors
Self-Defense and Use of Force
You can use physical force in self-defense when you reasonably believe it’s necessary to protect yourself or someone else from unlawful physical force. Deadly force is allowed only when a lesser degree of force would be inadequate and you reasonably believe you or another person faces imminent death or serious bodily injury. Deadly force is also authorized against someone who appears to be committing burglary, robbery, kidnapping, or sexual assault.18FindLaw. Colorado Code 18-1-704 – Use of Physical Force in Defense of a Person The statute does not impose a general duty to retreat, but you lose the self-defense claim if you provoked the confrontation or were the initial aggressor.
Protections inside the home are broader under the “Make My Day” law. If someone makes an unlawful entry into your dwelling and you reasonably believe they’ve committed or intend to commit a crime inside and might use even slight physical force against any occupant, you’re justified in using deadly force. Occupants acting within these limits are immune from both criminal prosecution and civil liability.19Justia. Colorado Code 18-1-704.5 – Use of Deadly Physical Force Against an Intruder
Local Ordinances Can Add More Restrictions
State law used to preempt local firearm rules. Senate Bill 21-256 ended that in 2021. Cities and counties can now enact their own ordinances covering the sale, purchase, transfer, and possession of firearms, ammunition, and accessories, as long as those rules are at least as restrictive as state law.20Colorado General Assembly. SB21-256 Local Regulation of Firearms
Boulder has used that authority to ban assault weapons, large-capacity magazines, bump stocks, and ghost guns, and to prohibit open carry in public places.21City of Boulder. Gun Violence Prevention Ordinances Denver has its own restrictions, including an open carry ban. What’s legal on one side of a city or county line may not be legal on the other. Before carrying or transporting firearms through an unfamiliar area, check the local ordinances.