Uninsured and Underinsured Motorist Coverage, Explained

An uninsured motorist claim is a first-party claim on your own auto policy. It pays your losses when the at-fault driver has no insurance, carries too little insurance, or flees the scene. Uninsured motorist (UM) and underinsured motorist (UIM) coverage sit on your own policy, and you file the claim with your own insurer, not the other driver's.

This guide is general information, not legal advice. Coverage rules, state requirements, and surcharge limits differ by state and change over time. Carriers sell this coverage and law firms advertise around it, so a plain account of what it pays, what it does not, and how to claim it is harder to find than it should be.

What is the difference between uninsured and underinsured motorist coverage?

Uninsured motorist (UM) coverage pays your losses when the at-fault driver carries no liability insurance or cannot be identified. Underinsured motorist (UIM) coverage pays the gap when the at-fault driver's liability limits are too low to cover your losses. Both sit on your own policy.

The Insurance Information Institute describes this as coverage that "provides compensation to policyholders when an at-fault motorist has no liability insurance" or "is a hit-and-run driver." UM answers the no-coverage problem; UIM answers the not-enough-coverage problem. UIM pays only the amount above the at-fault driver's liability limit, not the full loss a second time.

Coverage	When it pays	Whose policy
Uninsured motorist (UM)	The at-fault driver has no liability insurance, or fled and cannot be identified (hit-and-run)	Your own policy
Underinsured motorist (UIM)	The at-fault driver has insurance, but the liability limits are too low to cover your losses	Your own policy

Because both are first-party coverages, your own insurer handles the claim. That is the structural difference from a standard liability claim, where you pursue the at-fault driver's insurer. You can read the full comparison in the third-party claim process against the other driver's insurer, which covers the path you take when the other driver does carry adequate coverage.

When does uninsured/underinsured motorist coverage pay?

Uninsured and underinsured motorist coverage pays in three situations: the at-fault driver carries no insurance, the at-fault driver fled and cannot be identified in a hit-and-run, or the at-fault driver's liability limits fall short of your losses. It stops paying once your own coverage limit is reached.

Those three trigger scenarios cover most claims:

• Uninsured at-fault driver. The other driver caused the crash and had no liability insurance. Your UM coverage stands in for the coverage the at-fault driver should have carried.
• Hit-and-run or phantom vehicle. The at-fault driver fled and was never identified. In many states a UM claim treats an unidentified driver like an uninsured one, though some states require a police report or physical contact. The criminal side of a fled driver is separate; that is covered in the steps to take after a hit-and-run.
• Underinsured at-fault driver. The at-fault driver had insurance, but the liability limit was lower than your losses. UIM pays the difference up to your own UIM limit.

UM and UIM are separate from Personal Injury Protection (PIP). In a no-fault state, PIP pays your own medical and economic losses regardless of who caused the crash, while UM and UIM address the different problem of an at-fault driver who cannot pay. The Insurance Information Institute lists twelve true no-fault states plus Puerto Rico, where mandatory PIP applies, in its overview of no-fault auto insurance.

Do you actually need uninsured motorist coverage?

Uninsured motorist coverage protects you when the other driver cannot pay, which liability coverage never does. Its limits, stacking rules, and whether it covers property damage vary by state and policy. Read your declarations page to confirm your current UM and UIM limits.

The reason this coverage exists is measurable. The Insurance Research Council estimated that more than one in seven drivers (15.4 percent) were uninsured nationally in 2023, and more than one in six (18.0 percent) were underinsured, so that one in three drivers (33.4 percent) carried no coverage or too little, according to its report released in 2025 and summarized by the Insurance Information Institute. Liability coverage pays other people for damage you cause; it does nothing for you when someone else causes the crash and cannot pay.

The honest limits matter as much as the value:

• UM and UIM pay only up to your own UM or UIM limit. Losses above that limit are not covered.
• The coverage protects you and your passengers. It does not pay the at-fault driver's losses.
• Whether UM covers property damage to your vehicle, versus only bodily injury, varies by state.
• Stacking rules, which combine limits across vehicles or policies, vary by state and policy.
• UIM pays only the gap above the at-fault driver's liability limit, not the entire loss again.

Your declarations page, the summary your insurer issues with the policy, lists your UM and UIM limits in dollar figures. Checking it is the fastest way to know what you already carry.

How do you file an uninsured motorist claim?

Filing an uninsured motorist claim goes through your own insurer in five steps: notify your insurer promptly, open a UM or UIM claim, receive a claim number and adjuster, submit the crash report and documentation, and follow up in writing.

1. Notify your own insurer promptly. Report the collision to your own insurer as soon as possible and state that the other driver was uninsured, underinsured, or fled the scene.
2. Open a UM or UIM claim. Ask your insurer to open the claim under your uninsured or underinsured motorist coverage, filed against your own policy rather than the other driver's.
3. Get a claim number and adjuster. Your insurer assigns a claim number and a claims adjuster who becomes your point of contact for the claim.
4. Submit the crash report and documentation. Send the crash report, dated photos, repair estimates, and any medical bills the adjuster requests.
5. Follow up in writing. Track the claim number, answer the adjuster's requests, and confirm each decision in writing.

Large insurers such as Geico, Progressive, and State Farm each run their own UM and UIM intake by phone and online. Use the claim channel listed on your own policy, because this is a claim against your coverage. The Driver's Privacy Protection Act (18 U.S.C. 2721) permits an insurer to use motor-vehicle-record information for claims investigation, which is why your insurer can pull and review the crash report your claim references. If the at-fault driver did carry adequate insurance, your claim is a liability claim against that insurer instead, and a UM claim does not apply.

Is uninsured motorist coverage required in your state?

Uninsured motorist coverage is mandatory in some states, required to be offered on an opt-out basis in others, and optional elsewhere. Requirements vary by state. Confirm your state's rule with your state department of insurance or the NAIC before assuming you carry it.

"In about 20 jurisdictions, uninsured motorist coverage is mandatory," according to the Insurance Information Institute; "in other states, insurers are required to offer the coverage but a driver does not have to purchase it." Whether UIM is bundled with UM, and whether property-damage UM exists at all, also depends on the state. These are general facts, not legal advice for your situation, and no single state is named as mandatory here without its own statute behind it. Your state department of insurance publishes the rule for your state, and the National Association of Insurance Commissioners lists every state regulator. Confirm your own requirement there before assuming a crash is covered.

Does filing an uninsured motorist claim raise your rates?

An uninsured motorist claim is not a claim against your own at-fault record, because the other driver caused the crash. Whether an insurer may surcharge for it varies by state and company. Several states restrict surcharges for not-at-fault claims. Check your state department of insurance.

The mechanism, not a dollar figure, is what to understand. A surcharge is a rate increase an insurer applies after a claim, and states regulate when one is allowed. Some states bar a surcharge for a not-at-fault claim, including many UM and UIM claims where the other driver was responsible; others leave the decision to the carrier. No single national rule sets the amount, and no reliable average applies to every driver, so any specific figure would be a guess. Your state department of insurance publishes the surcharge rules for your state, and the NAIC directory above points to it.

How does the police report support an uninsured motorist or hit-and-run claim?

A crash report documents the parties, vehicles, and scene your own insurer uses to investigate an uninsured motorist claim. In a hit-and-run, it records the reported details and that the other driver fled. The officer's fault notation is an observation, not a verdict.

The report is the evidence your own insurer works from, and in a hit-and-run it also records that you reported the collision and what you were able to describe. An officer's opinion of fault is not a legal finding; in Florida, the reporting driver's own crash statement "may not be used as evidence in any trial, civil or criminal" under Florida Statutes 316.066. The report documents the collision; it does not declare who is guilty, and a driver who fled is not proven at fault by the report alone.

Access to the report itself varies by state. Florida keeps crash reports confidential for 60 days, releasing them in that window only to the parties involved, their insurers, their legal representatives, and other enumerated requesters; Texas limits reports to interested parties and gives everyone else a redacted copy under Texas Transportation Code 550.065. As a party to your own crash, you generally qualify, but confirm your state's rule before assuming any report is open to anyone. To reach the correct channel, find where your crash was reported and how to request the report in the directory.

A crash report and a public-records lookup are not a consumer report under the Fair Credit Reporting Act (15 U.S.C. 1681a). This information supports your own insurance claim. It is never a tool to screen a tenant, an employee, or an applicant.

Your next step

Check your declarations page for your UM and UIM limits, because those figures decide what a claim can pay. An uninsured or hit-and-run claim leans on the crash report, so find where your crash was reported and how to request it in the accident-report directory. Then confirm your state's UM requirement and its surcharge rules with your state department of insurance before you assume how a claim will be handled.