Motorcycle Accident Laws in Montana (2026): Helmets

A motorcycle crash in Montana is handled as a personal injury case, but riders face questions a car driver does not: who has to wear a helmet, whether going without one can affect a damages award, and whether moving between lanes is allowed. Montana is one of a small group of states that has legalized a limited form of lane filtering, so the rules here differ from most of the country. Over all of this sit the two rules that decide every injury case, the deadline to sue and how shared fault affects recovery.

This page explains both the general tort rules and the motorcycle-specific variables in Montana. It is general legal information and attorney advertising, not legal advice, and outcomes turn on the specific facts, so confirm how the law applies with a licensed Montana attorney.

Statute of Limitations in Montana

Under MCA 27-2-204, an action for an injury to the person founded on a liability not created by a written instrument must be commenced within three years. For a motorcycle crash, that clock generally starts on the date of the collision. Missing the deadline almost always ends the case, so confirming the date early is essential.

A few situations can change the deadline. A minor's time is generally tolled until age 18, and legal incapacity can pause the clock. Claims against a governmental entity carry their own notice and presentment requirements, which can shorten the practical window, so those should be flagged early. Because these are fact-specific, confirm your exact deadline with a licensed attorney.

Wrongful Death in Montana

When a motorcycle crash causes death, the claim proceeds under Montana's wrongful death and survival statutes, brought by or on behalf of the surviving heirs or the estate. The deadline is three years under MCA 27-2-204, which for a death claim runs from the date of death, with a longer ten-year period applying only where the death resulted from a homicide. Because these timelines are fact-specific, confirm the exact period with a licensed Montana attorney.

Negligence Rule: Modified Comparative Negligence

Montana uses modified comparative negligence under the 'not greater than' standard, codified at MCA 27-1-702. Contributory fault does not bar recovery as long as the injured person's fault was not greater than the combined fault of the defendants and any nonparties, but damages are reduced in proportion to the injured person's share. In practice, a rider who is 50 percent at fault can still recover, with the award cut in half, but a rider who is 51 percent or more at fault recovers nothing. That 50 percent line is the key difference from a pure-comparative state.

For riders, comparative fault means the defense will try to push the rider's share over the line, using arguments about speed, lane position, or conspicuity, because crossing 51 percent ends the claim entirely. There is also a documented bias against motorcyclists among some jurors and adjusters, which is one more reason to document that the rider was operating lawfully.

No-Fault and PIP

Montana is not a no-fault state. It uses a traditional at-fault (tort) system and does not require PIP. The driver who caused the crash, and that driver's insurer, is responsible for the harm, and there is no statutory injury threshold a rider must clear before suing. A seriously injured rider pursues the at-fault driver directly and may also rely on their own uninsured or underinsured-motorist coverage if the at-fault driver lacks adequate insurance.

Helmet Law: Partial

Montana has a partial helmet law. Under MCA 61-9-417, only an operator or passenger under 18 must wear protective headgear that meets the standard set by the Montana Department of Justice. A person may not operate a motorcycle on a highway unless any passengers under 18 are wearing a helmet. A licensed adult rider may legally ride without a helmet. The practical takeaway is that most adult riders may lawfully ride bare-headed, but riders and passengers under 18 may not.

Helmet Non-Use as Evidence

Because adults may legally ride without a helmet in Montana, the helmet question is a damages issue rather than a question of breaking the law. Under the state's comparative-negligence framework, a defendant may argue that a rider's choice to ride without a helmet increased the severity of a head injury and ask the jury to assign part of the fault to that choice. In a modified-comparative state with a 51 percent bar, that argument can carry extra weight, because added fault attributed to the rider can move the case toward the cutoff. The argument still turns on causation and usually requires expert proof, since a helmet protects the head, not road rash, orthopedic, or internal injuries.

Lane Filtering and Lane Splitting

Montana is one of the few states that expressly allows a narrow form of lane filtering. Under MCA 61-8-392, the operator of a two-wheeled motorcycle may engage in lane filtering, defined as overtaking and passing a vehicle that is stopped or traveling at 10 mph or less in the same lane and direction, when the road has lanes wide enough to pass safely, the motorcycle is not operated at more than 20 mph while overtaking, and conditions permit continued reasonable and prudent operation. This is lane filtering, not lane splitting. Filtering through faster moving traffic or exceeding the speed conditions is not allowed, and doing so at the time of a crash can be used by the defense on the question of fault.

Damage Caps and State Insurance

Montana does not cap most compensatory personal-injury damages such as medical bills, lost income, and pain and suffering in ordinary negligence cases. Punitive damages are limited by statute, and a separate cap applies to noneconomic damages in medical-malpractice claims, but those limits do not apply to a typical motorcycle-crash claim against an at-fault driver.

For coverage context, Montana's minimum auto-liability requirement is 25/50/20: $25,000 per person and $50,000 per accident for bodily injury, and $20,000 for property damage. The same minimums apply to motorcycles. Because serious motorcycle injuries can far exceed a minimum policy, a rider's own underinsured-motorist coverage is often important.

Why a Motorcycle Case Is Different

A motorcycle crash is rarely minor. With far less protection than a car, riders suffer more severe injuries, which means higher medical costs and a more aggressive insurance defense. Montana cases also carry rider-specific questions, the partial helmet law and any helmet-causation argument, the lane-filtering conditions, and the 51 percent fault bar, all set against a documented bias toward riders that makes proof of lawful conduct central.

Preserving Evidence and How to Evaluate Your Options

If you or a family member was hurt in a motorcycle crash, get medical care and keep the records, obtain the police crash report, photograph the scene, the bike, and your gear, and note the other driver's information and any witnesses. Then speak promptly with a licensed Montana attorney, both because of the three-year deadline (and the shorter notice rules for government claims) and because early evidence shapes the comparative-fault analysis, which matters especially given the 51 percent bar.

Most motorcycle accident attorneys offer a free consultation and work on a contingency basis, meaning no upfront fee and payment only out of any recovery. No attorney can promise an outcome or a dollar amount, and only a licensed Montana attorney can assess your specific facts within the deadline. None of this is legal advice, and reading it does not create an attorney-client relationship.