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uninsured motorist coverage
Uninsured motorist coverage can help when an at-fault driver has no insurance. Underinsured motorist coverage can help when the at-fault driver’s limits are too low for your losses.
Reader goal
Decide whether UM/UIM limits should match or exceed liability limits.
What this page helps you decide
- Separate UM from UIM and bodily injury from property damage.
- Check hit-and-run and phantom vehicle rules in your state.
- Compare at-fault driver limits against your medical and wage risk.
- Review stacking options when allowed.
Primary sources checked
- NAIC: Uninsured Motorists
- NAIC: What You Should Know About Auto Insurance Coverage
- NAIC: State Insurance Departments
UM, UIM, UMPD, deductibles, offsets, stacking, and rejection rules are state-specific. Read the endorsement and confirm the rule with your regulator or insurer.
Internal planning tool
Pressure-test your liability limits
Compare limits against household risk before you request like-for-like quotes or speak with a licensed agent.
Open liability toolUninsured motorist coverage may help when a legally responsible driver has no liability insurance. Underinsured motorist coverage may help when that driver's limits are insufficient for a covered loss. State rules and policy wording determine what is available.
The NAIC uninsured motorists overview reports that an estimated 15.4% of motorists were uninsured in 2023. That national estimate does not predict a specific driver's risk or replace current state data.
UM, UIM, and UMPD are different
UM bodily injury
May cover eligible injury losses caused by an uninsured or qualifying hit-and-run driver.
UIM bodily injury
May apply after the at-fault driver's available liability insurance is insufficient.
UM property damage
May cover vehicle damage where offered; deductibles and hit-and-run rules vary.
What a claim may require
- Prompt notice to your own insurer.
- Evidence of fault and the other driver's insurance status.
- Police and witness information for a hit-and-run.
- Medical, wage, or repair documentation.
- Compliance with consent-to-settle and cooperation conditions.
Stacking, offsets, and limits
Stacking can combine limits from more than one vehicle or policy in some circumstances; other states or forms restrict it. UIM calculations may also use different offset methods. Do not assume stacking is automatically available or always the better purchase. Request the applicable endorsement and a written price comparison.
How to review your options
- Confirm whether UM/UIM is required, optional, or rejectable.
- Record bodily injury and property damage components separately.
- Compare limits alongside liability, not in isolation.
- Ask about stacking, offsets, household exclusions, and hit-and-run requirements.
- Keep any rejection or selection form with the policy.
Health insurance is not a substitute
Health insurance may pay eligible treatment subject to its own network, deductible, and cost-sharing rules. It does not perform the same role as UM/UIM and may not address the same categories of loss. Compare the coverages rather than treating either as a complete replacement.
Use the NAIC regulator directory to verify local rules.
