Uninsured & Underinsured Motorist Claims (UM/UIM): What to Know

You did everything right — and the driver who hit you has no insurance, or a minimum policy that does not begin to cover your injuries. This is exactly the situation uninsured/underinsured motorist (UM/UIM) coverage exists for. It is coverage on your own policy that pays when the at-fault driver cannot.

UM vs. UIM: The Difference

• Uninsured Motorist (UM) applies when the at-fault driver has no liability insurance at all — or in hit-and-run cases where the driver is never identified.
• Underinsured Motorist (UIM) applies when the at-fault driver has insurance, but not enough to cover your damages. Your UIM coverage makes up part of the gap.

Why This Coverage Matters So Much

Roughly 1 in 8 U.S. drivers is uninsured, and many more carry only state-minimum limits — often $25,000 or less. If you suffer a $120,000 injury and the at-fault driver has a $25,000 policy, that policy is exhausted almost immediately. Without UM/UIM coverage, the remaining $95,000 comes out of your own pocket.

How a UIM Claim Works

1. You first pursue the at-fault driver’s liability policy and typically recover its limit ($25,000 in the example).
2. You then turn to your own UIM coverage for the shortfall, up to your UIM policy limit.
3. Your insurer steps into the shoes of the at-fault driver — meaning you now negotiate your injury claim against your own insurance company.

The Uncomfortable Truth: Your Insurer Becomes the Adversary

Here is what surprises most people: in a UM/UIM claim, your own insurer has a financial incentive to minimize your payout, just like any other insurer. The same tactics apply — lowball offers, disputing the severity of injuries, requesting recorded statements. Being a loyal, premium-paying customer does not change the economics of the claim.

Common UM/UIM Disputes

• Whether the other driver was truly “underinsured” — how limits stack and offset varies by state.
• The value of your injuries — the same valuation fight as any injury claim.
• “Phantom vehicle” proof in hit-and-run cases — some states require corroborating evidence of the unidentified vehicle.
• Consent-to-settle clauses — settling with the at-fault driver without notifying your UIM insurer first can jeopardize your UIM claim. Always notify your insurer before accepting the liability settlement.

How to Protect Your UM/UIM Claim

1. Check your own policy now — confirm you carry UM/UIM and at what limits. It is inexpensive and one of the most valuable coverages you can own.
2. Notify your insurer promptly after an accident involving an uninsured or low-limit driver.
3. Do not settle with the at-fault insurer without first getting your UIM insurer’s written consent.
4. Document your injuries as rigorously as you would in any claim — reach MMI before valuing the claim.

Should You Get a Lawyer for a UM/UIM Claim?

Often yes — because you are negotiating against a professional insurer on your own policy, and the disputes (stacking, offsets, consent-to-settle) get technical fast. For serious injuries exceeding the at-fault driver’s limits, representation typically pays for itself. See our guide on whether you need a lawyer.

Estimate your total injury value with the calculator first — that number tells you how much of the gap your UIM coverage needs to fill.