Uninsured motorist (UM) coverage pays for your injuries and sometimes your vehicle damage when a driver with no insurance hits you. Underinsured motorist (UIM) coverage kicks in when the at-fault driver's policy limits are too low to cover your losses. Together they fill the gap left by the other driver's failure. 22 US states plus DC require UM coverage. The rest leave it optional, but given that roughly 13% of US drivers are uninsured, it is strongly worth carrying.
Uninsured motorist coverage: key facts
| Coverage type | What it pays | Required? |
|---|---|---|
| UM bodily injury (UMBI) | Medical bills, lost wages, pain & suffering for you and your passengers | Required in 22 states + DC |
| UM property damage (UMPD) | Repair or replacement of your vehicle | Required in fewer states; often has a small deductible |
| Underinsured motorist (UIM) | Gap between the at-fault driver's limit and your actual losses | Often bundled with UM; required in some states |
| Hit-and-run | Covered by UM in most states if the vehicle makes physical contact | Covered under UM policy |
Why uninsured motorist coverage exists
Liability insurance pays for damage you cause to others. But what protects you when an uninsured driver causes damage to you? Your own collision coverage can repair the vehicle (minus deductible), but it does not pay for your medical bills, lost wages or pain and suffering. Uninsured motorist coverage fills that gap — it steps into the shoes of the liability insurance the at-fault driver should have had.
About 13% of US drivers had no insurance in 2023 (Insurance Research Council). In some states the rate is over 20%. Florida, Mississippi and New Mexico consistently rank among the highest.
UM vs UIM: the difference
Uninsured motorist (UM): the at-fault driver has zero insurance. Your UM coverage pays as if you were making a claim against their (non-existent) liability policy.
Underinsured motorist (UIM): the at-fault driver has insurance but their limits are insufficient — for example, they carry a $25,000 bodily injury limit and your medical bills are $80,000. Your UIM coverage pays up to the gap, subject to your own UIM limit.
Most policies offer both in a single UM/UIM endorsement. Limits typically mirror your liability limits, and many experts recommend matching them — if you carry 100/300 liability, carry 100/300 UM/UIM.
What UM/UIM covers — and what it does not
Typically covered
- Medical expenses for you and your passengers
- Lost wages due to inability to work after the accident
- Pain and suffering (in states that allow it under UM)
- Funeral expenses
- Vehicle damage (UMPD, where available)
- Hit-and-run accidents (in most states, if physical contact was made)
Typically not covered
- Your own vehicle damage under UMBI (requires UMPD or collision for that)
- Hit-and-run without physical contact in some states — you must prove another vehicle caused the damage
- Incidents where you are at fault
- Losses above your UM/UIM policy limits
How a UM/UIM claim works
- Report the accident to your insurer just as you would any other claim.
- Your insurer investigates as if they were the liability insurer of the at-fault driver.
- You must prove the other driver was at fault and uninsured or underinsured.
- For UIM, the at-fault driver's insurer must pay their limit first; your UIM pays any remaining gap.
- Some states allow you to stack UM/UIM limits across multiple vehicles on the same policy — this can significantly increase your available coverage.
If you have two vehicles insured under the same policy and each has $100,000 in UM coverage, 'stacking' allows you to claim up to $200,000 from a single accident. About half of US states permit stacking in some form. Check your policy and state laws.
UK and India equivalents
In the UK, the Motor Insurers' Bureau (MIB) compensates victims of uninsured and untraced (hit-and-run) drivers. You claim through the MIB rather than your own insurer. The MIB pays for personal injury and, in some circumstances, vehicle damage, subject to a £300 excess for uninsured drivers.
In India, uninsured third-party claims are handled through the Motor Accident Claims Tribunal (MACT). India mandates third-party insurance for all vehicles, but enforcement is uneven. The Solatium Fund covers victims of uninsured and hit-and-run accidents up to set limits.
Frequently asked questions
Is uninsured motorist coverage required?
Does UM coverage pay for vehicle damage?
What if I am hit by a hit-and-run driver?
How much UM/UIM coverage should I carry?
Can my insurer cancel UM/UIM coverage?
Sources & further reading
- Insurance Research Council — Uninsured Motorists
- Insurance Information Institute — Uninsured Motorist Coverage
Figures, prices and policy details were current at the last-updated date above. Automotive pricing, incentives and regulations change frequently — verify time-sensitive details with the linked primary sources. Read our editorial policy and fact-checking standards.
