Updated July 2026
What Is Uninsured and Underinsured Motorist Coverage Insurance?
Uninsured motorist coverage (UM) pays when the at-fault driver has no insurance. Underinsured motorist coverage (UIM) pays when the at-fault driver's liability limits are too low to cover your medical bills, lost wages, and vehicle damage. Your own carrier writes the check, up to the UM/UIM limits you purchased. Oregon law requires carriers to offer UM/UIM at limits equal to your liability coverage, and you must reject it in writing if you don't want it.
- A driver with no insurance rear-ends you at a stoplight. You have $8,000 in medical bills and $5,000 in vehicle damage. The at-fault driver has no liability coverage to pay your claim. Your UM coverage pays the $8,000 in medical costs up to your UM bodily injury limit. Your uninsured motorist property damage coverage (if you added it) pays the $5,000 vehicle repair, minus your deductible.
- A driver with minimum liability limits causes a crash that leaves you with $75,000 in medical bills and $15,000 in lost income. The at-fault driver's liability policy pays its $25,000 bodily injury limit. You still need $65,000. If you carry $100,000 in UIM coverage, your carrier pays the remaining $65,000. Without UIM, you're left trying to collect from the at-fault driver personally, which rarely succeeds.
- A vehicle forces you off the road and flees. You have $12,000 in vehicle damage and $6,000 in medical costs. Oregon UM coverage requires proof of physical contact with the uninsured vehicle. Without a witness, dashcam footage, or paint transfer, your UM claim will be denied. Collision coverage would pay the vehicle damage regardless of contact proof, but it won't cover your medical bills.
Who Needs Uninsured and Underinsured Motorist Coverage Insurance?
You need UM/UIM if you drive in Oregon, where approximately 13% of drivers are uninsured. It's the only coverage that pays your medical bills and lost income when the at-fault driver has no insurance or insufficient limits. If you carry minimum liability limits, consider UM/UIM limits higher than your liability coverage to protect yourself from underinsured drivers.
If the at-fault driver's liability limit is lower than your potential medical costs and lost wages, UIM pays the difference. Estimate your medical coverage gap: if your health insurance has high deductibles or excludes auto accidents, carry UM/UIM limits equal to or higher than your liability limits. If you can't afford to pay your own medical bills after an uninsured driver hits you, don't reject this coverage.
How Much Does Uninsured and Underinsured Motorist Coverage Insurance Cost?
UM/UIM coverage typically adds $8 to $18 per month to an Oregon auto insurance premium, or approximately $95 to $215 annually, depending on the limits you select and whether you add uninsured motorist property damage coverage.
- UM/UIM limits you select — higher limits cost more, and Oregon requires carriers to offer limits equal to your liability coverage
- Whether you add uninsured motorist property damage coverage, which pays for vehicle damage caused by an uninsured driver
- Your liability limits — UM/UIM is priced as a percentage of your liability premium, so higher liability limits increase UM/UIM cost
- Whether Oregon allows stacking, which lets you combine UM/UIM limits across multiple vehicles on the same policy to increase the total available coverage
- Your county's uninsured driver rate — counties with higher percentages of uninsured drivers see higher UM/UIM premiums