Uninsured motorist (UM) coverage pays for your injuries and (in some states) property damage when the at-fault driver has no insurance. Underinsured motorist (UIM) coverage applies when the at-fault driver has insurance but not enough to cover your losses. About 20 states require UM coverage by statute, and roughly 14 percent of U.S. drivers are uninsured according to Insurance Research Council data.
TipMatch your UM/UIM to your liability limits. The premium cost is usually small and protects you against the financially worst drivers.
⚠ Written rejectionIf you decline UM where it is offered, you typically must sign a written waiver. Many carriers default you in unless you actively reject. Read the declarations page.
What UM and UIM actually cover
Coverage varies by state, but the core protections are similar nationwide.
- UM Bodily Injury (UMBI): medical bills, lost wages, pain and suffering when the at-fault driver has no insurance.
- UM Property Damage (UMPD): damage to your vehicle, available in some states only.
- UIM: same coverages but kicks in when the at-fault driver's limits are exhausted.
- Hit-and-run: most states' UM coverage applies if the other driver flees.
States that require UM coverage
About 20 states require UM by statute, typically at minimum bodily injury limits. UIM is required in fewer states.
- UM required: Connecticut, Illinois, Kansas, Maine, Maryland, Massachusetts, Minnesota, Missouri, Nebraska, New Hampshire, New York, North Carolina, North Dakota, Oregon, South Carolina, South Dakota, Vermont, Virginia, West Virginia, Wisconsin, D.C. (list reflects general practice; confirm with your state).
- UIM commonly required as a stacked option where UM is required.
- Many other states require carriers to offer UM and accept a signed written rejection if the consumer declines.
How much you should carry
Most experts recommend matching your UM/UIM limits to your liability limits. The cost difference is modest and the protection is significant.
- State minimums (often 25/50 BI) are inadequate against any serious injury.
- Recommended: 100/300 UMBI/UIMBI to match a reasonable liability limit.
- Stacking (where allowed): combines limits across vehicles or per-claim units, multiplying available coverage.
How UIM "fills the gap"
A UIM claim pays the difference between what the at-fault driver's policy paid and your UIM limit, up to your actual losses.
- Example: Other driver has $25,000 BI limits. Your medical bills are $80,000. You carry $100,000 UIMBI.
- You collect $25,000 from the other driver's carrier.
- You collect up to $75,000 from your own UIM coverage ($100,000 limit minus the $25,000 already paid in offset states; or full $100,000 in "stacking" or non-offset states).
📚 Legal & Regulatory References
- Insurance Research Council (IRC), Uninsured Motorists 2023 report (national uninsured rate estimate).
- State UM/UIM statutes (varies widely; see Va. Code 38.2-2206, N.Y. Ins. Law 3420(f)).
- NAIC consumer guide, "Uninsured and Underinsured Motorist Coverage."
- III (Insurance Information Institute) data on UM/UIM availability and cost.
⚖ DisclaimerThis page is general consumer information, not legal or insurance advice. State laws and individual policy terms vary. For high-value disputes consult a licensed attorney or your state's department of insurance.
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❓ Frequently Asked Questions
Is uninsured motorist coverage required?
In about 20 states yes. In other states the carrier must offer it and you can sign a written rejection. Even where optional, it is widely recommended.
How is UM different from UIM?
UM applies when the at-fault driver has no insurance. UIM applies when they have insurance but not enough. Many states sell them as a combined coverage; a few sell them separately.
Does UM cover hit-and-run accidents?
Yes, in most states. The unidentified driver is treated as uninsured under your policy. Some states require independent corroboration (witness, police report).
Does UM cover my own injuries as a pedestrian?
In most states yes, if you are struck by an uninsured driver. Your auto UM coverage typically follows you as a pedestrian or cyclist, not just inside your car.
What does it cost to add UM/UIM?
Typically $50-$200 per year for 100/300 limits, depending on state and driving record. Stacking can increase the cost but multiplies effective coverage.
Can I sue the uninsured driver myself?
Yes, but uninsured drivers usually have no assets to collect from. UM coverage is your practical recovery. After your carrier pays, they may subrogate against the uninsured driver, but you typically do not benefit further.