Uninsured and Underinsured Motorist Coverage: The Protection Most Drivers Overlook
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In this article
Millions of drivers share the road without adequate insurance. Learn what UM and UIM coverage do and why they matter.
Key Takeaways
- Roughly one in eight U.S. drivers is uninsured, according to the Insurance Research Council.
- UM coverage protects you when the at-fault driver has no insurance; UIM covers the gap when their limits are too low.
- UM/UIM is mandatory in some states and optional in others — check your state's requirements.
- Medical bills, lost wages, and pain and suffering can all be covered under UM/UIM, depending on your policy.
- Adding UM/UIM to an existing policy is typically one of the most cost-effective coverage upgrades available.
Why the At-Fault Driver's Insurance Isn't Always Enough
Most drivers assume that if someone else causes a crash, that driver's liability insurance will cover the costs. That assumption holds — but only when the at-fault driver actually has adequate coverage. In reality, a significant share of American motorists are either completely uninsured or carry only the minimum limits required by their state.
State minimum liability limits are often as low as $25,000 per person for bodily injury. A single hospitalization can exceed that figure before follow-up care, physical therapy, or lost income are even factored in. If the at-fault driver's policy runs out, you're left chasing the difference from someone who may have little to no assets to collect from.
This is the coverage gap that UM and UIM are specifically designed to close. For a broader look at how all the core coverage types fit together, see how liability, collision, and comprehensive coverage work.
1 in 8
U.S. drivers estimated to be uninsured
According to the Insurance Research Council's periodic estimates, approximately 12–13% of motorists on American roads carry no auto insurance.
$25,000
Common state minimum bodily injury limit
Many states set their minimum liability requirement at $25,000 per person — a figure that can be exhausted by a single emergency room visit.
22 states
States requiring UM/UIM coverage
Roughly half of U.S. states mandate uninsured or underinsured motorist coverage; the remainder require only that insurers offer it or make it entirely optional.
How UM and UIM Coverage Actually Work
Uninsured motorist (UM) coverage applies when the driver who caused your accident carries zero insurance. It can pay for your medical bills, your passengers' injuries, and — depending on your state and policy — damage to your vehicle.
Underinsured motorist (UIM) coverage applies when the at-fault driver has insurance, but their limits are exhausted before your losses are fully compensated. Your UIM policy essentially steps in to bridge the gap between what their insurer paid and what your damages actually totaled.
Both coverages generally include two sub-types: bodily injury (covering medical costs, lost wages, and pain and suffering) and property damage (covering vehicle repairs). Not every state offers or mandates both sub-types, so reading your actual policy documents matters. If any of the terminology feels unfamiliar, the auto insurance terms glossary is a useful plain-language reference.
What UM/UIM Coverage Typically Pays For
Subject to your policy limits and state rules, UM/UIM coverage can address:
- Medical and hospital expenses for you and passengers in your vehicle
- Rehabilitation costs such as physical therapy or specialist visits
- Lost income if injuries prevent you from working
- Pain and suffering in states that allow non-economic damages under UM claims
- Vehicle repair or replacement under property damage sub-coverage, where available
What UM/UIM does not cover is your own liability to others — that's handled by your liability coverage. It also doesn't replace comprehensive or collision coverage for other types of damage. Understanding how all these pieces interact is key; see coverage gaps that leave drivers exposed after an accident for a fuller picture of where policies commonly fall short.
Match Your UM/UIM Limits to Your Liability Limits
A practical starting point when selecting UM/UIM limits is to mirror them against your liability coverage amounts. If you carry $100,000/$300,000 in liability, consider the same in UM/UIM. This creates a symmetrical safety net — the same protection you extend to others is extended back to you. Talk to a licensed agent to confirm what makes sense for your income, health coverage, and asset exposure.
Making an Informed Decision About Your Policy
Whether UM/UIM is mandatory in your state or optional, the decision about how much to carry deserves careful thought. A widely cited starting point: match your UM/UIM limits to your liability limits so the protection is symmetrical. Beyond that, consider your health insurance situation — if your medical coverage is thin, robust UM/UIM limits can be especially valuable.
Adding or increasing UM/UIM coverage is usually among the least expensive upgrades you can make to a policy, often adding only a modest amount to your premium. For a full orientation on how all the parts of an auto insurance policy work together, Auto Insurance Decoded provides a comprehensive starting point.
Every policy is different, and coverage terms, exclusions, and pricing vary by insurer and state. A licensed insurance agent or your state's department of insurance can help you evaluate what level of UM/UIM coverage makes sense for your specific situation.
This article is for general informational purposes only and is not personalized insurance or legal advice. Coverage terms, availability, and requirements vary by state and provider. Consult a licensed insurance professional and review your actual policy documents before making coverage decisions.
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Autos & Vehicles Editorial Team
Autos & Vehicles Editorial Team is the collective byline for our editorial team and contributor network. Articles published under this byline or an editorial pen name are researched, written, and reviewed according to our editorial standards for clarity, consistency, and independence before publication.
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