Last updated · By Mustafa Bilgic
What UM and UIM coverage actually do
Most states let — or require — you to carry uninsured motorist (UM) and underinsured motorist (UIM) coverage on your own auto policy:
- UM pays when the at-fault driver has no liability insurance, or in hit-and-run cases where the driver flees.
- UIM pays the gap when the at-fault driver has some insurance, but not enough to cover your injuries.
Because the Insurance Information Institute estimates that about 14% of drivers nationwide are uninsured (far higher in some states), these coverages are often the only realistic source of compensation after a serious crash.
How a UM/UIM payout is calculated
The injury itself is valued exactly as in any car-accident claim: general damages for pain and suffering, plus special damages for medical bills, lost wages and future losses. The crucial difference is the policy-limit cap. Your UM/UIM recovery cannot exceed the per-person limit you bought — commonly $25,000, $50,000, $100,000 or higher.
UIM “offset” rules
For an underinsured claim, many states reduce your UIM recovery by what the at-fault driver’s insurer already paid. If your damages are $100,000, the at-fault driver carried $30,000, and your UIM limit is $100,000, you may recover the $30,000 from them plus up to $70,000 in UIM (the rules vary by state — some “add” limits instead of offsetting). Always check your state’s approach.
Practical tips for a UM/UIM claim
- Report quickly — UM policies have strict notice and, for hit-and-run, sometimes physical-contact or prompt-reporting requirements.
- Mind the cap — review your declarations page; raising UM/UIM limits is usually inexpensive.
- Watch for arbitration clauses — many UM policies resolve disputes through arbitration rather than a jury.
- Your own insurer is now the adversary — a UM claim is still a claim, so the same documentation discipline applies.
Uninsured motorist claims — frequently asked questions
How much can I get from an uninsured motorist claim?
Your UM/UIM claim is valued like any injury claim — pain and suffering plus medical bills and lost wages — but it is capped at your own UM/UIM policy limit. A $120,000 injury on a $50,000 limit recovers $50,000, so the coverage you bought sets the ceiling.
What is the difference between UM and UIM?
Uninsured motorist (UM) coverage pays when the at-fault driver has no insurance or flees the scene. Underinsured motorist (UIM) coverage pays the shortfall when the at-fault driver has some insurance but not enough to cover your losses.
Does a UM claim raise my insurance premium?
Making a legitimate UM/UIM claim for an accident that was not your fault should not, by itself, increase your premium in most states, although rules vary. The coverage exists precisely for this situation.
How common are uninsured drivers?
The Insurance Information Institute estimates roughly 14% of US drivers — about one in seven — are uninsured, with rates much higher in some states. That is why carrying adequate UM/UIM coverage is widely recommended.
Is this uninsured motorist calculator accurate?
It is a realistic guide that values the injury and applies your policy-limit cap, not a guarantee. Actual UM/UIM recoveries depend on your state’s offset rules, policy terms and the evidence. Always confirm with a qualified attorney.