Uninsured Motorist Coverage: What It Is and When You Need It

Say you're driving home from work and someone runs a red light. They T-bone your car. You're shaken but okay. The other driver has no insurance, gives you a fake name, or just drives off. Now what?

This is the gap uninsured motorist coverage fills. The U.S. Department of the Treasury's Federal Insurance Office estimates that about 14% of U.S. drivers carry no insurance, which works out to roughly one in seven [1]. Yet most drivers either skip uninsured motorist coverage in states where it's optional or carry the state minimum, which often isn't enough to cover a serious injury.

This guide walks through what uninsured motorist coverage actually does, which states require it, how much you should carry, what stacked coverage means, and how hit-and-run claims work. By the end, you'll know whether you're protected or quietly betting against the math.

The Short Answer: What Uninsured Motorist Coverage Does

Uninsured motorist (UM) coverage pays your medical bills and, in some states, your car repairs when the at-fault driver has no insurance or can't be found (a hit-and-run). Underinsured motorist (UIM) coverage pays the gap when the at-fault driver has insurance but their limits aren't enough to cover your damages.

Three quick distinctions:

1. UM bodily injury (UMBI) covers medical bills, lost wages, and pain and suffering when an uninsured driver hurts you or your passengers.
2. UM property damage (UMPD) covers your car repairs when an uninsured driver damages your vehicle. Not every state offers it, and some bundle it with UMBI.
3. UIM covers the difference between the at-fault driver's policy limits and your actual damages. The other driver had $25,000 in liability and your hospital bill was $90,000? UIM bridges the $65,000 gap.

Who Actually Needs Uninsured Motorist Coverage in 2026

The Treasury FIO 2025 report found that about 14% of U.S. drivers carry no insurance at all [1]. That national average masks wild state variation. The Insurance Information Institute's state ranking shows the rate ranging from under 6% in Maine to roughly 28% in Mississippi, with Georgia at about 19% [2].

The math is straightforward. Roughly one in seven drivers nationally cannot pay for the damage they cause. If you don't carry uninsured motorist coverage, you're either filing through your collision coverage (with a deductible and a fight) or trying to collect from someone who, as one personal injury attorney put it on Reddit, is "judgment proof," meaning broke and uncollectible.

The "Overpaying Detector" lens here is sharp. Drivers in mandatory-UM states often carry only the state minimum, which evaporates quickly on a real injury. Drivers in optional states reject coverage entirely, often without seeing the cost difference. Both groups are exposed in ways they don't realize.

Which States Require Uninsured Motorist Coverage?

About half of U.S. states plus the District of Columbia require uninsured motorist coverage in every auto policy [3]. The other half make it optional, but in nearly every optional state you have to reject the coverage in writing on the application or quote form. Two outliers exist: New Hampshire doesn't require any auto insurance at all, and Virginia lets drivers opt out of auto insurance for a fee [3]. Our state requirements data page lists the minimum liability and UM/UIM rules for every state.

A few state-specific points worth knowing:

• Texas sells uninsured/underinsured coverage with a statutory $250 deductible, which is usually much lower than your collision deductible. If you don't want the coverage, you have to turn it down in writing [4].
• California updated minimum liability limits to 30/60/15 in 2025 and offers UM/UIM as an option that must be rejected in writing [5].
• Illinois requires uninsured motorist bodily injury limits of at least $25,000 per person and $50,000 per accident on every policy [6].
• Maryland mandates UM coverage and publishes a consumer advisory walking through how UM claims actually get paid and what your rights are [7].
• Florida doesn't require bodily injury liability for most drivers (the no-fault system uses PIP and PDL instead), and UM coverage is optional but recommended [8].

If you've recently moved to a new state, your old UM election doesn't automatically carry over. The new state's rules apply.

How Much Uninsured Motorist Coverage Should You Carry?

The rule insurance professionals consistently endorse is to match your UM limits to your bodily injury liability limits. If you carry 100/300 liability (meaning $100,000 per person and $300,000 per accident), carry 100/300 UM.

Here's why. Liability protects the other driver from your at-fault claim. UM protects you from the other driver's at-fault claim. If you wouldn't want a stranger to come after you with less than $100,000 in protection, you shouldn't want less than $100,000 in protection when a stranger comes after you.

The dollar math sharpens this. The Treasury FIO 2025 report calculated the average bodily injury liability claim severity at $24,211 in 2022 [1]. The average property damage liability claim ran $5,313 in the same year [1]. State-minimum UM limits in many states top out at $25,000 per person. That cap might cover an average claim, but a moderate hospitalization with surgery and rehab will sail past it.

Say you carry $25,000 in UM bodily injury and an uninsured driver hits you. Your back surgery and physical therapy run $80,000. Your UM pays the first $25,000. The remaining $55,000 falls on your health insurance (which doesn't pay for lost wages or pain and suffering) and, ultimately, you.

If you're not sure what limits you currently carry, you can check your declarations page or compare quotes to see what proper UM coverage costs in your state.

How Much Does Uninsured Motorist Coverage Cost?

This is the honest part: uninsured motorist coverage is one of the most variably priced add-ons in auto insurance. Some carriers price UM tightly to your liability cost; others price it as a near-throwaway add-on; others use it as a margin lever. Carriers don't publish UM-only pricing cleanly, and aggregate cost data isn't broken out at the cohort level in the public NAIC database.

For context, the national average full-coverage premium runs about $150 per month, or $1,803 per year, based on NAIC data adjusted for current motor vehicle insurance CPI [9][10]. UM is typically a small addition to that figure, but the cost spread between carriers for the same UM limits can be significant. The only reliable way to know your number is to get comparison quotes.

Stacked vs Unstacked Uninsured Motorist Coverage

Stacked uninsured motorist coverage lets you multiply your UM limits by the number of vehicles on your policy. Say you have two cars on the same policy with $50,000 of UM each. In a stacking state, you can stack the limits to $100,000 in a single accident. In a non-stacking state, your maximum recovery from that policy is $50,000 no matter how many vehicles are on it.

Stacking is allowed in a limited set of states. Florida, Michigan, Pennsylvania, Connecticut, and a few others permit it; the rules and pricing vary state to state. The premium add for stacking is usually modest given the multiplier effect, which makes it one of the better-leverage decisions in a multi-vehicle household.

The catch: some states allow you to "stack" only within the same policy, and others allow you to stack across multiple policies you own. Check your state's rules with your DOI before you assume your existing policy stacks.

Hit-and-Run Accidents: How Uninsured Motorist Coverage Pays

In most states, a hit-and-run driver is treated as uninsured for the purposes of your own policy. If they can't be identified or held responsible, your UM coverage steps in.

Say a driver clips your bumper in a parking lot and leaves before you get back. You file a police report and a witness gives you a partial plate that doesn't lead anywhere. If you carry UM property damage, your carrier processes the repair claim under UM, often at the lower UM deductible (in Texas, $250) [4]. If you carry only collision, you can still file, but you'll pay your collision deductible, which is usually higher than the UM deductible.

A few practical points:

• Most states require a police report filed within a specific window (usually 24 to 72 hours) for the claim to qualify as a hit-and-run.
• Photo evidence of damage and any witness contact information dramatically strengthens the claim.
• Some states require physical-contact evidence between the two vehicles to file UM for hit-and-run [7].

For a step-by-step on the broader claims process, see what to do after a car accident.

Should You Ever Reject Uninsured Motorist Coverage?

Almost never. At a 14% national uninsured rate [1], the statistical math is against you in every state. Even in low-uninsured-rate states, hit-and-run claims alone justify carrying UM.

The narrow case where rejection might make sense: a high-net-worth driver with a separate umbrella policy that explicitly covers uninsured-motorist exposure across all vehicles. Most umbrella policies don't actually do this without a specific endorsement. Don't assume your umbrella covers UM unless you've read the schedule of coverages.

If you do reject UM in an optional-rejection state, the rejection must be in writing on the policy application or quote, per state law [4]. Verbal rejections don't count.

How to File an Uninsured Motorist Claim

Filing a UM claim feels backwards because you're filing against your own policy. Your carrier then "subrogates," which means they sue or recover from the at-fault driver behind the scenes on your behalf.

The basic flow:

1. Call the police at the scene. A police report is required for UM claims in most states, especially for hit-and-run.
2. Document everything. Photos of damage, witness names and phone numbers, and the other driver's plate if you can get it.
3. Notify your carrier within their reporting window. Most policies require notification within 24 to 72 hours.
4. File the UM claim against your own policy. Your adjuster will ask for medical records, repair estimates, and the police report.
5. Let your carrier handle subrogation. They'll pursue the at-fault driver if there's anything to recover. You don't have to fight that battle yourself.

Rate impact varies by state. California is one of the states where UM not-at-fault claims do not cause a rate increase [5]. Other states allow surcharges for any claim filed, including UM. If a UM claim gets denied, your state DOI complaint process is the next step, and our guide on what to do after a claim denial walks through it.

FAQ

Is uninsured motorist coverage the same as full coverage?

No. "Full coverage" usually means liability plus collision and comprehensive. Uninsured motorist coverage is a separate add-on that's sometimes bundled with full coverage and sometimes sold as a stand-alone option. Always check your declarations page to see which UM coverages and limits you actually carry.

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

Yes in most states. Hit-and-run drivers are treated as uninsured for the purposes of your own policy, so your UM coverage steps in. A police report and any physical evidence (paint transfer, witness contact, partial plate) help process the claim. Some states require specific physical-contact evidence between vehicles for UM to apply [7].

Will my rate go up if I file an uninsured motorist claim?

It depends on the state. California prohibits rate increases for not-at-fault UM claims [5]. Other states allow carriers to surcharge any claim filed, even one you didn't cause. If you're unsure how your state treats UM claim surcharges, ask your carrier in writing or check your state DOI.

What is the difference between UM and UIM?

UM (uninsured motorist) pays when the at-fault driver has no insurance at all. UIM (underinsured motorist) pays when the at-fault driver has insurance but their limits aren't enough to cover your damages. Some states sell UM and UIM together as one coverage; others sell them separately.

What does $100k/$300k/$100k mean?

Those numbers describe coverage limits. The first is the maximum payout per person for bodily injury, the second is the maximum payout per accident for all bodily injuries combined, and the third is the maximum payout for property damage. So 100/300/100 means $100,000 per person, $300,000 per accident, $100,000 in property damage. The same shorthand applies to UM limits when written as UM 100/300/100.

Can I add uninsured motorist coverage mid-policy?

Yes. Most carriers let you add or change UM coverage mid-term. The premium gets prorated for the remaining policy period. If you've just had a close call with an uninsured driver, there's no rule that says you have to wait until renewal to fix the gap.

The Bottom Line

Uninsured motorist coverage is the single coverage that protects you from the 1-in-7 driver who can't pay for the damage they cause [1]. Carrying state-minimum UM in a state where roughly one in five drivers is uninsured isn't saving money; it's betting against the math. Rejecting UM entirely is betting harder.

Three steps to take this week:

1. Pull your declarations page and write down your current UM/UIM limits.
2. Compare those to your bodily injury liability limits. If your UM is lower, that's the gap to fix.
3. Get comparison quotes that include UM/UIM at properly matched limits. The cost varies sharply between carriers, and you can't know your number without comparing.

Compare rates from top carriers in about two minutes at quotefii.com.

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