Updated July 2026
What Is Uninsured and Underinsured Motorist Coverage Insurance?
Uninsured motorist coverage (UM) pays for your medical bills, lost wages, and vehicle damage when you're hit by a driver with no insurance. Underinsured motorist coverage (UIM) kicks in when the at-fault driver has insurance but their liability limits are too low to cover your full claim. Both coverages protect you and your passengers — your own liability policy only pays the other driver's expenses, not yours. UM/UIM is the only coverage that fills the gap when the person who caused the crash can't pay.
- You're rear-ended at a stoplight by a driver with no insurance. You have $18,000 in medical bills and $9,000 in vehicle damage. The at-fault driver has no policy to file a claim against. Your uninsured motorist coverage pays the full $27,000 up to your policy limits. Without UM coverage, you'd pay out of pocket or sue the uninsured driver directly — a process that rarely recovers meaningful money.
- A driver runs a red light and T-bones your car. You have $45,000 in medical expenses. The at-fault driver carries Oklahoma's minimum liability limit of $25,000 per person. Their insurer pays the $25,000 maximum. Your underinsured motorist coverage pays the remaining $20,000 up to your UIM policy limit. Without UIM, you'd be responsible for the $20,000 gap.
- A driver sideswiped your car on the highway and fled. You have $12,000 in vehicle damage and $8,000 in medical bills. Police couldn't identify the driver. Your uninsured motorist coverage treats this as an uninsured driver claim and pays the full $20,000 up to your limits. Without UM, you'd file under collision coverage for the vehicle damage only — your medical bills wouldn't be covered unless you have personal injury protection or health insurance.
Who Needs Uninsured and Underinsured Motorist Coverage Insurance?
You should carry uninsured and underinsured motorist coverage if you live in Oklahoma, where one in seven drivers has no insurance and many others carry only the state minimum $25,000 per person liability limit. If a serious collision puts you in the hospital with $50,000 in medical bills and the at-fault driver has no coverage or a $25,000 limit, UM/UIM is the only coverage that pays the gap. It's especially important if you don't have health insurance with strong coverage or if you're the primary income earner in your household — a major injury without UM/UIM can leave you personally liable for tens of thousands in medical debt.
Compare the annual cost of UM/UIM to your health insurance deductible and out-of-pocket maximum. If your health plan has a $10,000 out-of-pocket max and UM/UIM costs $150 per year, the coverage pays for itself if you're hit by an uninsured driver once every 65 years. If you have no health insurance or a high-deductible plan, UM/UIM is non-negotiable — it's your only protection against uninsured drivers in a state where 14% of drivers carry no coverage.
How Much Does Uninsured and Underinsured Motorist Coverage Insurance Cost?
Uninsured and underinsured motorist coverage typically adds $8 to $18 per month to your premium, or $96 to $216 annually.
- Your UM/UIM coverage limits — higher limits cost more, but the per-dollar cost decreases as limits increase.
- Whether you select stacked or unstacked coverage — stacked UM/UIM multiplies your per-vehicle limit by the number of vehicles on your policy, increasing both protection and cost.
- Your ZIP code's uninsured driver rate — areas with higher percentages of uninsured motorists see higher UM/UIM premiums.
- Your liability limits — carriers often tie UM/UIM pricing to your liability coverage tier, with higher liability limits triggering slightly higher UM/UIM rates.
- Whether you include property damage under UM — some states and carriers separate UM for bodily injury from UM for property damage, with the latter adding cost.