Maine AR-15 Gun Laws: Waiting Period, Carry, and Yellow Flag

Maine AR-15 gun laws are among the more permissive in the Northeast: the state has no assault weapons ban, no magazine capacity limit for ownership, and no license or registration requirement for rifles. You can buy an AR-15 in its standard factory configuration, with a pistol grip, telescoping stock, flash suppressor, or threaded barrel, and keep it with standard 30-round or larger magazines.¹² The rules that will actually affect you are the 72-hour waiting period on purchases, a five-round magazine cap when hunting, restrictions on how you transport the rifle in a vehicle, and a set of prohibited locations.

What You Can Legally Own

Maine does not restrict cosmetic or functional features on rifles. There is no state-level list of banned attachments, and no requirement to modify a factory AR-15 for compliance. A license is not required to own a rifle.³

Suppressors are legal with the federal ATF tax stamp, and Maine imposes no additional state permit. Suppressors can be used for target shooting and for hunting.⁴

Who Can Buy or Own One

Federal law requires you to be 18 to buy a long gun from a licensed dealer. Maine private-sale rules add a wrinkle for minors: no one other than a parent, foster parent, or guardian can sell or transfer a long gun to someone under 16, and non-family members cannot sell to a person 16 or 17, though transfers such as gifts within that age range are not prohibited outright.⁵

Title 15, Section 393 of the Maine Revised Statutes bars several categories of people from possessing any firearm:

Anyone convicted of a crime punishable by one year or more of imprisonment, under Maine, federal, or another state’s law.
Anyone adjudicated as a juvenile for conduct that would have been a disqualifying felony if committed as an adult.
Anyone subject to a qualifying domestic violence protection order that includes a credible-threat finding or prohibits the use of physical force.
Anyone involuntarily committed, found not criminally responsible by reason of insanity, or found not competent to stand trial.
Fugitives, unlawful drug users, people dishonorably discharged, and people who have renounced U.S. citizenship.

Most violations are Class C crimes, punishable by up to five years in prison and a $5,000 fine. A violation based on a prior felony conviction is a Class B crime, carrying up to 10 years and a $20,000 fine.⁶⁷

Cannabis Users Are Prohibited

Maine has legalized medical and recreational marijuana, but federal law still lists cannabis as a controlled substance, and Section 393 prohibits firearm possession by any unlawful user of a controlled substance. Because marijuana remains illegal federally, cannabis users are swept into that prohibition.⁶ ATF Form 4473 asks buyers whether they are an unlawful user of marijuana or another controlled substance; answering dishonestly is a federal crime with penalties up to 10 years. Holding a Maine medical marijuana card effectively disqualifies you from buying a firearm from a dealer.

Buying an AR-15: the 72-Hour Waiting Period and Background Checks

In 2024, Maine enacted LD 2238, signed as Public Law Chapter 678, creating a 72-hour waiting period. A seller cannot deliver a firearm to a buyer until at least 72 hours after the two agree to the sale. This applies to sales from licensed dealers and to private sales that go through a dealer.⁸

The waiting period does not apply to:

Sales between spouses, domestic partners, parents, children, grandparents, grandchildren, siblings, aunts, uncles, nieces, or nephews.
Law enforcement and corrections officers, and licensed private security guards.
Sales between dealers.
Antique firearms and curio/relic transfers between licensed collectors.
Transactions where no background check is required under state or federal law.

There is no exception for concealed handgun permit holders.⁹

Every dealer sale triggers a background check through the FBI’s National Instant Criminal Background Check System.¹⁰ Even a fast “proceed” result does not shorten the 72-hour clock.

Private Sales

Maine does not require a background check for every private sale, but a 2024 law added two categories that do: sales at gun shows, and sales resulting from advertisements. An advertisement includes any message posted in writing, on television, radio, or online. Post an AR-15 for sale on a website or social media, and the buyer has to clear a background check facilitated by a licensed dealer. Purely private, unadvertised sales between individuals who know each other are exempt. Completing a covered private sale without a background check is a Class C crime, punishable by up to five years.¹¹

Carrying and Transporting

Open Carry

Maine’s Constitutional Carry law removed the concealed-permit requirement, but it applies to handguns, not rifles.¹² Open carry of a rifle like the AR-15 is generally legal without a permit, provided you are not carrying it in a way meant to threaten or alarm others. No statute sets up a permit framework for rifles because none is required.

In a Vehicle

Transporting a loaded AR-15 inside a vehicle is illegal under Title 12, Section 11212-A. A rifle counts as loaded if a cartridge is in the chamber or in an attached magazine. To transport lawfully, remove the magazine and clear the chamber. The statute permits loaded handguns in vehicles for non-prohibited adults 21 and older, but that exception does not extend to rifles.¹³

Off-Limits Places

Schools: possessing a firearm on public or approved private school property, or discharging one within 500 feet of school property, is a Class E crime, up to six months in jail and a $1,000 fine.¹⁴
Courthouses: unauthorized possession is a Class D crime, up to one year and a $2,000 fine. A concealed handgun permit is not a defense.¹⁵
State parks: firearms are prohibited under Bureau of Parks and Lands rules.¹²
Private property: an owner can ban firearms from the premises. Watch for posted signage.

Hunting: the Five-Round Magazine Limit

This is the rule that catches AR-15 owners off guard. Ownership has no magazine cap in Maine, but hunting does. Any semi-automatic rifle used for hunting can hold no more than five rounds in the magazine plus one in the chamber, for a maximum of six. A standard 30-round magazine has to be swapped out or permanently altered to hold five before you go afield.⁴

Caliber matters too. Rifles chambered in .17 or .22 rimfire cannot be used for deer, moose, or bear, with an exception for .22 magnum for deer. A standard AR-15 in .223 Remington or 5.56 NATO uses centerfire cartridges and is not caught by the rimfire restriction. Fully automatic firearms are banned for hunting entirely; a semi-automatic AR-15 is legal for hunting as long as the magazine limit is met. Tracer and explosive ammunition is also banned for hunting.⁴

Self-Defense

Maine allows deadly force in self-defense when you reasonably believe it is necessary because another person is about to use unlawful deadly force against you or a third person, or is committing or about to commit a kidnapping, robbery, or sexual assault.¹⁶

Maine is not a pure stand-your-ground state. You have a duty to retreat if you can do so with complete safety, unless you are in your own home and were not the initial aggressor. Inside your dwelling, deadly force is allowed if you reasonably believe someone has entered or is trying to enter without permission and that deadly force is necessary to prevent bodily injury to anyone present. You lose the justification if you provoked the encounter with intent to cause harm, or if you could safely surrender property to someone with a colorable claim to it.

Maine’s Yellow Flag Law

Maine uses a yellow flag system rather than a red flag law. A family member or acquaintance cannot directly petition a court to have your firearms removed. The process starts with law enforcement.

An officer with probable cause to believe a person possesses or may acquire a dangerous weapon, and who takes that person into protective custody, can request an assessment by a medical practitioner. The practitioner evaluates whether the individual presents a “likelihood of foreseeable harm,” meaning a substantial risk of serious physical harm to self or others based on recent behavior, threats, or attempts at violence or self-harm.¹⁷

If the practitioner certifies that standard is met, an initial 30-day restriction takes effect immediately, barring the person from buying, possessing, or controlling any dangerous weapon. The district attorney then has five days to file a petition for judicial review, and a court hearing must occur within 14 days. A judge can dissolve the restriction or extend it up to one year on clear and convincing evidence that the person continues to pose a risk. Extended restrictions can be renewed annually after further hearings. During the restriction, firearms are held by law enforcement, and the person has a right to legal representation and a hearing.¹⁷

1
Everytown Research & Policy. Assault Weapons Prohibited
2
Everytown Research & Policy. High Capacity Magazines Prohibited
3
Giffords. Maine Gun Laws
4
Maine Dept of Inland Fisheries and Wildlife. Laws Pertaining to Hunting Equipment
5
Giffords. Minimum Age To Purchase and Possess Laws in Maine
6
Maine Legislature. Maine Code Title 15 Section 393 – Possession of Firearms Prohibited for Certain Persons
7
Maine State Legislature. Maine Revised Statutes 17-A Section 1704 – Maximum Fine Amounts
8
Maine State Legislature. Maine Code Title 25 Section 2016 – Waiting Period After Sale of Firearm
9
Maine.gov Department of Public Safety. Advisory on 72 Hour Waiting Period
10
Federal Bureau of Investigation. Firearms Checks (NICS)
11
Maine State Legislature. Maine Code Title 15 Section 395 – Background Checks of Firearms Buyers
12
Maine State Police. Concealed Carry in Maine
13
Maine Legislature. Maine Code Title 12 Section 11212-A – Having a Loaded Firearm or Crossbow in a Motor Vehicle
14
Maine State Legislature. Maine Code Title 20-A Section 6552 – Firearms
15
Maine Legislature. Maine Code Title 17-A Section 1058 – Unauthorized Possession of Firearm in Courthouse
16
Maine State Legislature. Maine Code Title 17-A Section 108 – Physical Force in Defense of a Person
17
Maine State Legislature. Maine Code Title 34-B Section 3862-A – Extreme Risk Protection Orders