Uninsured and Underinsured Motorist Coverage, Explained
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- Uninsured motorist (UM) coverage can pay you when you're hurt by a driver with no insurance, or by a hit-and-run driver.
- Underinsured motorist (UIM) coverage can help when the at-fault driver's insurance isn't enough to cover your losses.
- Both usually come from your own auto policy, and the rules and limits depend on your state and policy.
- Read your policy's declarations page now, before you need it.
- Tell your insurer about a crash promptly, since policies often set notice deadlines.
Here's a nasty surprise that catches people out: you're hit by a driver at fault, and they have no insurance at all, or a policy so small it won't cover your hospital bill. Who pays then?
For many drivers, the answer is their own insurance company, through two coverages most people don't think about until it's too late. This guide explains what they are and what to look at in your own policy. It's general information; policies and state laws differ.
Uninsured motorist coverage (UM)
Uninsured motorist coverage reimburses you if you're injured by a driver who has no insurance, or by a hit-and-run driver who can't be identified. It's coverage you buy as part of your own auto policy, and it steps in where the other driver's insurance would normally have paid.
Underinsured motorist coverage (UIM)
Underinsured motorist coverage applies when the at-fault driver does have insurance, but their limits are too low to cover your losses. It pays the gap, up to your own policy limit and subject to your policy's terms. Some policies and states require you to use up the at-fault driver's coverage first.
Quick comparison
| Situation | Coverage that may apply |
|---|---|
| Other driver has no insurance | Uninsured motorist (UM) |
| Hit-and-run, driver never found | Uninsured motorist (UM), subject to policy terms |
| Other driver's limits are too low | Underinsured motorist (UIM) |
| Other driver is insured and limits are enough | Their liability coverage |
What to check in your own policy
- Do you have it? Look at the declarations page, the summary at the front of your policy.
- Your limits. UM and UIM have their own dollar limits, which may be lower than your liability limits.
- Who is covered. Policies usually cover you, family members in your household and passengers, but terms differ. They may also cover you as a pedestrian or cyclist.
- Notice and reporting rules. Some policies expect prompt notice, a police report for hit-and-run, or other steps.
- Physical contact or witness requirements. Some policies apply special conditions to hit-and-runs where the driver is never identified.
If it happens to you
- Get medical care and call the police, even if the other driver begs you not to.
- Collect the other driver's details if you can, and photos of the scene.
- Notify your own insurer promptly and ask whether UM or UIM applies.
- Keep medical bills, pay records and all communication with insurers.
Remember that these claims are still insurance claims, so the usual care applies: give accurate facts, avoid guessing and don't sign anything you don't understand. Filing deadlines also apply. See the deadline finder.
Frequently asked questions
Is uninsured motorist coverage required?
It depends on the state. Some states require it, some require insurers to offer it and some leave it optional.
Does it cover me if I'm walking or biking?
Often it can, but terms vary by policy. Check your policy wording or ask your insurer.
Will using UM or UIM raise my rates?
Policies and states differ. Ask your insurer how claims are treated.
What if I don't know if I have it?
Check the declarations page of your policy or ask your agent. Do this before you need it.
Sources and references
- A Consumer's Guide to Auto Insurance, National Association of Insurance Commissioners, hosted by the Tennessee Department of Commerce and Insurance (tennessee.gov)
- Your state's official sources: the state legislature's online statutes, your state court system's self-help pages, and your state insurance department.
This article is educational and is not legal advice. We are not a law firm and do not refer or recommend lawyers. Laws differ by state and change over time. Read our Legal Disclaimer and Editorial Policy.