Uninsured-motorist coverage rules, state by state.

Why UM/UIM coverage matters

Roughly one in eight U.S. drivers is uninsured, and many more carry only state-minimum liability policies that run out well before catastrophic medical bills are paid. UM and UIM coverage on your own policy fill that gap. UM applies when the at-fault driver has no insurance at all; UIM applies when the at-fault driver has some insurance but the limits are insufficient to cover the damages.

In serious-injury cases, UM/UIM coverage is often the largest single source of recovery. Plaintiffs' lawyers verify available coverage early because the answer determines case strategy. A $300,000 UIM policy combined with a $25,000 at-fault liability policy yields $325,000 in available coverage; the same case with no UIM yields only $25,000.

Stacking , the ability to combine UM/UIM limits across multiple vehicles on the same policy or multiple policies , can multiply available coverage substantially. About half of U.S. states allow stacking by default; the rest either prohibit it or allow it only with specific endorsements.

Full state-by-state table

UM/UIM coverage limits to consider

Most state UM/UIM minimums (typically $25,000 per person, $50,000 per accident) are inadequate for any serious-injury case. A single helicopter ride to a trauma center can cost $50,000 to $100,000; surgical treatment for a herniated disc can run $80,000 to $150,000; a moderate TBI can produce lifetime care costs in the millions. State-minimum UM/UIM coverage is rapidly exhausted by even routine injury cases. Plaintiffs' attorneys consistently recommend coverage at $300,000 to $500,000 per person, sometimes higher for households with significant assets.

The premium cost for higher UM/UIM limits is typically modest. UM/UIM claims are far less frequent than liability claims because they require the at-fault driver to be uninsured or underinsured. Carriers price the coverage accordingly: doubling UM/UIM limits from $50,000 to $100,000 might add only $30 to $60 per year to the premium. The cost-benefit calculation strongly favors carrying more than the state minimum.

How to find out if your policy includes UM/UIM coverage

The declarations page of your auto-insurance policy lists every coverage you have, including UM and UIM, with the policy limits for each. Request a copy of the declarations page from your insurance agent or download it from the carrier's customer portal. UM and UIM limits are typically listed separately from liability limits and use the same per-person / per-accident format (e.g., "UM 100/300" means $100,000 per person, $300,000 per accident). If you cannot find UM or UIM limits on the declarations page, your policy either does not include the coverage or includes it at the state-minimum level.

Many policyholders have less UM/UIM coverage than they realize. The state-minimum UM coverage in most jurisdictions is $25,000 per person, which is rapidly exhausted by even moderate medical bills. Plaintiffs' counsel routinely recommend UM/UIM coverage at $300,000 to $500,000 per person, matched to the liability coverage on the same policy. Premiums for higher UM/UIM limits are typically modest because UM/UIM claims are much less frequent than liability claims; carriers price the additional coverage attractively to make it easy to buy.

Phantom-vehicle (hit-and-run) claims under UM coverage

Hit-and-run accidents present a specific procedural challenge: the at-fault driver is unidentified, so there is no liability policy to claim against. UM coverage on the injured party's own policy is the only available source of recovery. Most state UM statutes and most insurance policies define a "phantom vehicle" or "hit-and-run" claim and impose requirements: typically, physical contact between the vehicles, or independent corroborating evidence such as eyewitness testimony, surveillance video, or police-report documentation. The purpose of these requirements is to prevent fabricated hit-and-run claims, but they can also defeat legitimate claims when the documentation is thin.

Plaintiffs in hit-and-run cases should immediately: (1) call 911 and obtain a police report, (2) photograph any damage and the scene, (3) identify and obtain contact information for any witnesses, (4) preserve dashcam footage from any nearby vehicles, and (5) request preservation letters for any commercial-property surveillance video in the area. The physical-contact requirement is satisfied by even minor contact, including debris that strikes the insured vehicle during the underlying collision.