Uninsured and Underinsured Motorist Coverage

Uninsured motorist (UM) and underinsured motorist (UIM) coverage can help when another driver causes an accident but has no liability insurance or does not have enough coverage for the loss. The details—what is covered, whether coverage is required or optional, and how much may be paid—depend on your state and policy. The NAIC recommends reviewing your policy and state-specific requirements before choosing auto coverage.

Key Takeaways

UM coverage may help with losses caused by an uninsured driver.
UIM coverage may apply when an at-fault driver’s liability limits are not enough, subject to the policy and state law.
Coverage for injuries, vehicle damage, hit-and-run crashes, passengers, and stacking varies by state and policy.
Compare your UM/UIM limits, exclusions, deductibles, and claim procedures with the rest of your auto policy.

What Is Uninsured Motorist Coverage?

UM coverage is part of an auto insurance policy that can respond when a driver who caused a crash does not have liability insurance. It is commonly described in separate bodily-injury and property-damage coverages, but availability and terms are not uniform nationwide.

Read your declarations page and policy form to see who is insured, which losses are covered, the applicable limits, and any deductible. Your insurer or state department of insurance can explain rules that apply where you live.

What Is Underinsured Motorist Coverage?

UIM coverage may apply when the at-fault driver’s liability insurance is insufficient for a covered loss. How an insurer calculates that amount can differ: a policy may use the other driver’s limits, the amount actually paid, or another method permitted by state law. Do not assume that UIM automatically pays every amount above the other driver’s liability limit.

If you are considering a claim, preserve the other driver’s insurance information, report the accident promptly, and ask your insurer about notice, consent-to-settle, and documentation requirements. Those requirements can affect a claim.

UM Bodily Injury and Property Damage

Policies may separate UM coverage into these categories:

UM bodily injury: May cover eligible injury-related losses for insured people, subject to the policy limit and state law.
UM property damage: May help with vehicle damage in states and policies that offer it. A policy may apply a deductible or set other conditions.

Collision coverage can be another way to insure damage to your own vehicle after a crash, regardless of whether the other driver has insurance. It is a separate coverage with its own deductible and terms. See our guide to auto insurance coverage types for a broader overview.

Is UM/UIM Required?

State rules control whether UM or UIM coverage is required, must be offered, or can be declined. The rules can also differ for bodily injury and property damage. Some states require written rejection of particular coverage, while others use different procedures.

Do not rely on a national state list when making a coverage decision. Check your state’s auto-insurance requirements, ask your insurer which options are available, and retain any coverage-selection or rejection documents.

How Much Does UM/UIM Coverage Cost?

There is no reliable national price for UM/UIM coverage. Premium depends on factors such as your state, chosen limits, vehicles, driving history, other coverages, insurer, and available discounts. Request a quote showing the cost of more than one limit option, then compare the limits and deductibles—not only the premium.

How UM/UIM Claims Work

A claim is generally made under your own policy, but the required steps and available benefits depend on the policy and state law. A cautious starting point is to:

Get medical help and report the crash when appropriate. A police report can be important evidence, especially if another driver cannot be identified.
Notify your insurer promptly and ask which UM/UIM coverage, deadlines, and documents apply.
Keep records such as photographs, witness information, medical bills, repair estimates, and the other driver’s insurance details.
Review any proposed settlement carefully. Ask whether accepting another insurer’s offer affects your UIM claim before you sign a release.

If you disagree with a coverage decision or payment, review the policy’s dispute provisions and contact your state department of insurance. For general claims context, see our auto claims step-by-step guide.

Choosing Limits

There is no one right UM/UIM limit for every driver. As you compare options, consider your liability limits, health coverage, household finances, vehicle coverage, and the policy rules that apply in your state. Ask the insurer to explain whether your selected limits apply per person, per accident, or in another way.

A licensed insurance professional can explain available policy options. For help reviewing the rest of your policy, see how much auto insurance you need.

Stacking and Hit-and-Run Claims

Some policies and states address whether UM/UIM limits can be combined across multiple vehicles or policies, often called stacking. Other policies restrict it. Hit-and-run coverage can also have state-specific conditions, including reporting and evidence requirements. Confirm both topics in your policy before assuming coverage applies.

Frequently Asked Questions

What is uninsured motorist coverage?

UM coverage may help with a covered loss caused by a driver without liability insurance. The covered people, losses, limits, and exclusions depend on the policy and state law.

Do I need uninsured motorist coverage?

Whether you must carry UM coverage depends on your state. Even where it is optional, compare the available limits, policy terms, and your ability to absorb a loss before declining it.

How much does uninsured motorist coverage cost?

Cost varies by insurer, state, selected limits, vehicle, driving history, and other rating factors. Ask for quotes at several limit levels so you can compare both price and protection.

What states require uninsured motorist coverage?

Requirements vary by state and can change. Use your state department of insurance and your insurer—not a generic national list—to confirm current requirements and any written-rejection rules.

Does uninsured motorist coverage cover a hit-and-run?

It may, but rules and claim conditions vary. Report a hit-and-run promptly and ask your insurer what evidence and notice it requires.

Does UM/UIM coverage protect passengers?

A policy may cover eligible passengers or household members in some circumstances, but the answer depends on the policy language and state law. Review the insured-person definition and ask the insurer about a specific situation.

Is UM/UIM the same as MedPay or PIP?

No. Medical payments coverage and personal injury protection are separate policy coverages. Their availability and benefits also vary by state and policy.

Will filing a UM/UIM claim raise my rates?

The effect of a claim can depend on state rules, insurer practices, and your policy. Ask your insurer how it treats not-at-fault and UM/UIM claims rather than relying on a general rule.

Next Steps

Review your declarations page for UM/UIM limits, deductibles, and endorsements.
Confirm your state’s current requirements with its department of insurance.
Ask your insurer for written quotes at different UM/UIM limits.
Keep your coverage-selection documents with your policy records.

Sources

National Association of Insurance Commissioners, “Auto Insurance”