Montana Does Not Require Underinsured Motorist Coverage
Montana does not mandate underinsured motorist coverage. The state requires only liability insurance: $25,000 per person for bodily injury, $50,000 per accident, and $20,000 for property damage. Underinsured motorist coverage is optional, and you must affirmatively decline it in writing if your carrier offers it.
This matters for households insuring two or more vehicles because a single collision can damage multiple cars. When the at-fault driver carries only Montana's minimum $20,000 property damage limit and your household sustains damage to two or three vehicles in one crash, that $20,000 splits across every damaged car. Underinsured motorist property damage coverage fills the gap between what the at-fault driver's policy pays and the actual repair cost across your vehicles.
Compare car insurance rates in your state
Get quotes from licensed carriers — no obligation, no spam, results in minutes.
Get Your Free QuoteMontana Property Damage Minimum
$20,000
The at-fault driver's property damage liability pays up to this limit per accident, not per vehicle. When a household's two or three cars are damaged in one collision, this amount must cover all of them combined.
Montana state minimum liability requirements
How Underinsured Motorist Coverage Works Across Multiple Vehicles
Underinsured motorist coverage applies when the at-fault driver's liability limit is lower than the damage they caused. Montana offers two forms: underinsured motorist bodily injury and underinsured motorist property damage. Bodily injury coverage pays medical expenses and lost wages when the at-fault driver's bodily injury limit cannot cover your household's injuries. Property damage coverage pays repair costs when the at-fault driver's property damage limit falls short.
For a multi-vehicle household, property damage exposure compounds quickly. A rear-end collision at a stoplight can damage two of your cars if one is pushed into the other. The at-fault driver's $20,000 property damage limit must cover both vehicles.
Underinsured motorist coverage is purchased per policy, not per vehicle. When you add a second or third car to your Montana policy, the underinsured motorist limit you selected applies to all vehicles on that policy. You do not buy separate underinsured motorist coverage for each car.
A single at-fault driver's $20,000 property damage limit must cover every vehicle damaged in the collision, including multiple cars from your household.
What Carriers Offer and How to Decline Coverage
When you add a vehicle to your policy or start a new policy, your carrier will present underinsured motorist coverage as an option. If you choose not to purchase it, Montana law requires you to sign a written rejection. This rejection is typically part of your policy application or a separate form the carrier provides. Without a signed rejection on file, the carrier may automatically include underinsured motorist coverage at the state minimum limit.
Most carriers writing in Montana offer underinsured motorist bodily injury and property damage as separate line items. You can decline one and purchase the other, or decline both. Households insuring multiple vehicles often purchase underinsured motorist property damage because the compounded exposure across two or three cars makes the coverage cost-effective relative to the risk of paying out-of-pocket repair costs when an at-fault driver carries only the minimum $20,000 limit.
Related Articles
Stacking and Per-Vehicle Limits
Montana does not allow stacking of underinsured motorist coverage. Stacking means combining the underinsured motorist limits from multiple vehicles on the same policy to create a higher total limit. Montana prohibits this.
Your underinsured motorist limit applies per accident, not per vehicle. If you purchase $50,000 in underinsured motorist property damage coverage and two of your cars are damaged in one collision, the $50,000 is the maximum the coverage will pay for both vehicles combined. The per-accident limit does not multiply by the number of cars on your policy.
This structure means households with higher-value vehicles or multiple cars may want to purchase underinsured motorist limits higher than the state minimum. The state minimum for underinsured motorist bodily injury mirrors the liability minimum: $25,000 per person and $50,000 per accident.
Montana Uninsured Motorist Rate
7.2%
One in fourteen Montana drivers carries no insurance. When an uninsured or underinsured driver causes a collision involving multiple vehicles from your household, your underinsured motorist coverage is the only layer protecting you from out-of-pocket repair costs beyond the at-fault driver's inadequate limits.
Montana state insurance statistics, 2023
Coordination with Collision Coverage
Underinsured motorist property damage coverage and collision coverage both pay for damage to your vehicles, but they apply in different situations. Collision coverage pays regardless of fault and applies when you collide with another vehicle, an object, or when your car rolls over. Underinsured motorist property damage coverage applies only when another driver is at fault and their property damage liability limit is too low to cover your damage.
If you carry collision coverage, you can file a claim under that coverage after a collision caused by an underinsured driver. Your carrier pays the repair cost minus your deductible, then pursues subrogation against the at-fault driver's insurer to recover what it paid. If the at-fault driver's limit is exhausted and your carrier cannot recover the full amount, you may still owe your deductible. Underinsured motorist property damage coverage, when present, can reimburse your deductible in this scenario, depending on your policy terms.
Households insuring multiple vehicles often carry both collision and underinsured motorist property damage coverage. Collision coverage handles single-vehicle accidents and at-fault collisions where you are responsible. Underinsured motorist property damage coverage handles the gap when another driver is at fault but underinsured. Together, the two coverages eliminate most out-of-pocket repair risk across your household's cars.
Compare Carriers That Write Multi-Vehicle Policies in Montana
Sixteen carriers write auto insurance in Montana and offer underinsured motorist coverage as part of their standard policy options. Allstate, Farmers, Geico, Progressive, State Farm, and USAA all write policies covering two or more vehicles and allow you to select underinsured motorist limits that apply across every car on the policy. Carriers price underinsured motorist coverage differently, and the cost varies based on the limit you select and the number of vehicles on your policy.
When you add a second or third vehicle to your Montana policy, request quotes that include underinsured motorist property damage coverage at limits matching or exceeding your liability limits. Compare the cost of adding underinsured motorist coverage against the out-of-pocket exposure your household faces when an at-fault driver's $20,000 limit must cover damage to multiple cars. Most households find the coverage cost is a fraction of the repair cost they would absorb without it.