2026-04-01 · personal, auto, coverage

Uninsured and Underinsured Motorist Coverage

Key Takeaways

Uninsured motorist (UM) coverage pays for your injuries and damages when the at-fault driver has no insurance.
Underinsured motorist (UIM) coverage pays the difference when the at-fault driver’s insurance is not enough to cover your losses.
About 14% of U.S. drivers are uninsured, making UM/UIM coverage one of the most important protections you can carry.
Many states require UM/UIM coverage, and even where it is optional, it is strongly recommended.

What Is Uninsured Motorist (UM) Coverage?

Uninsured motorist coverage is an auto insurance protection that pays for your medical bills, lost wages, and other damages when you are hit by a driver who has no liability insurance at all. It can also apply in hit-and-run accidents where the at-fault driver cannot be identified.

Without UM coverage, you would need to pay for your own medical treatment and vehicle repairs out of pocket if the other driver has no insurance and no assets to pursue in a lawsuit. Given that roughly 14% of drivers on the road carry no insurance (according to the Insurance Research Council), the risk is real and not uncommon.

What Is Underinsured Motorist (UIM) Coverage?

Underinsured motorist coverage picks up where the at-fault driver’s insurance stops. If another driver causes an accident and their liability limits are too low to cover your injuries and damages, UIM pays the difference up to your own policy limit.

For example, if your medical bills total $80,000 and the at-fault driver only carries $25,000 in bodily injury liability, their insurer pays $25,000. If you carry $100,000 in UIM coverage, your own policy can cover the remaining $55,000.

UM Bodily Injury vs. UM Property Damage

Uninsured motorist coverage comes in two forms:

UM Bodily Injury (UMBI): Covers medical expenses, lost income, and pain and suffering for you and your passengers when an uninsured driver is at fault. This is the more common and widely available form of UM coverage.
UM Property Damage (UMPD): Covers damage to your vehicle caused by an uninsured driver. Not all states offer UMPD as a separate coverage. In states where it is not available, collision coverage serves a similar purpose for vehicle damage.

If your state does not offer UMPD, carrying collision coverage on your auto insurance policy is the best way to protect against vehicle damage from an uninsured driver.

Do You Need UM/UIM Coverage?

Many states require drivers to carry UM coverage, UIM coverage, or both. Even in states where it is optional, insurers in some states must offer it and require you to sign a written rejection if you decline.

Whether your state mandates it or not, UM/UIM coverage is one of the most recommended auto coverages for several reasons:

Uninsured drivers are common. With roughly 1 in 7 drivers carrying no insurance, the odds of being hit by one are higher than most people expect.
Liability minimums are often low. Many states set minimum liability limits at $25,000 or $30,000 per person, which may not cover a serious injury. UIM fills that gap.
Hit-and-run protection. UM coverage typically applies to hit-and-run accidents where the other driver flees and cannot be identified.
It protects your finances. Medical debt from a serious accident can reach six figures. UM/UIM coverage keeps you from absorbing costs that should be someone else’s responsibility.

For details on your state’s minimum requirements, check with your insurer or your state’s department of insurance.

How UM/UIM Claims Work

Unlike most auto insurance claims, UM/UIM claims are filed with your own insurer, not the other driver’s. The process generally follows these steps:

Report the accident to the police and get a report documenting the other driver’s lack of insurance or insufficient coverage.
File a claim with your own insurer under your UM or UIM coverage.
Provide documentation including the police report, medical records, repair estimates, and proof of the other driver’s insurance status.
Your insurer investigates and determines the payout based on your policy limits and the verified damages.

Because you are filing against your own policy, UM/UIM claims can sometimes involve disputes over the amount owed. If your insurer’s offer seems low, you may have the right to demand appraisal or arbitration depending on your state and policy terms. For more on handling disputes, see our guide on claims denial and appeals.

For a broader overview of the claims process, see our auto claims step-by-step guide.

How Much UM/UIM Coverage Should You Carry?

A common recommendation is to match your UM/UIM limits to your liability limits. If you carry $100,000/$300,000 in bodily injury liability, carrying the same limits for UM/UIM ensures you have equivalent protection for yourself.

Factors to consider when choosing your limits:

Your health insurance. If you have strong health coverage, you may need less UMBI. However, UM coverage also pays for lost wages, pain and suffering, and other damages that health insurance does not.
Your vehicle value. If your car is valuable and your state offers UMPD, consider whether the coverage limit is sufficient. Otherwise, collision coverage handles vehicle damage.
Your overall coverage strategy. Your UM/UIM limits work alongside the rest of your policy. For help deciding on the right amount, see our guide on how much auto insurance you need.

Stacking vs. Non-Stacking

Some states allow “stacking,” which lets you multiply your UM/UIM limits across multiple vehicles on the same policy.

Stacked coverage: If you have $50,000 in UM coverage and two vehicles on your policy, stacking gives you $100,000 in total UM coverage for a single claim.
Non-stacked coverage: Your UM limit stays at $50,000 regardless of how many vehicles are on the policy.

Stacking is not available in every state, and it increases your premium. Ask your insurer whether your state allows it and whether the additional cost fits your budget.

Frequently Asked Questions

Does UM coverage apply to hit-and-run accidents?

Yes. In most states, uninsured motorist coverage applies when the at-fault driver flees the scene and cannot be identified. Some states require physical contact between the vehicles for UM to apply in a hit-and-run, while others do not.

Does UM/UIM coverage protect passengers?

Yes. UM and UIM coverage generally extends to passengers in your vehicle at the time of the accident. It may also cover you and your family members if you are injured as pedestrians or while riding in someone else’s car, depending on your policy terms.

Is UM/UIM coverage the same as MedPay or PIP?

No. Medical payments (MedPay) and personal injury protection (PIP) pay for your medical expenses regardless of who caused the accident. UM/UIM only applies when an uninsured or underinsured driver is at fault. These coverages can complement each other but serve different purposes.

Will filing a UM/UIM claim raise my rates?

It depends on your state and insurer. In many states, UM/UIM claims are not supposed to count against you because you were not at fault. However, some insurers may still factor claims history into your rates. Check your state’s rules and your insurer’s policy on not-at-fault claims.

Next Steps

Check whether your state requires UM/UIM coverage by reviewing the state auto insurance minimums hub.
Compare your current UM/UIM limits to your liability limits and consider matching them.
If you declined UM/UIM coverage in the past, contact your insurer to add it to your policy.
Review your full auto insurance package to make sure all coverages work together. Our guide on how much auto insurance you need can help.

Sources

Insurance Research Council (IRC), “Uninsured Motorists” study
Insurance Information Institute (iii.org), “Uninsured Motorists”
National Association of Insurance Commissioners (naic.org), auto insurance consumer resources
State department of insurance websites for UM/UIM mandate details