Updated July 2026
What Is Uninsured and Underinsured Motorist Coverage Insurance?
Uninsured motorist coverage pays when the driver who hit you has no insurance. Underinsured motorist coverage pays when their liability limits are too low to cover your medical bills and vehicle damage. Both coverages step in after the at-fault driver's insurance is exhausted or confirmed absent, and they apply to hit-and-run crashes where the other driver is never identified. Connecticut bundles these as UM/UIM coverage and requires carriers to offer it at limits matching your liability coverage.
- You're rear-ended at a red light. The other driver has no insurance. You have $18,000 in medical bills and $9,000 in vehicle damage. The at-fault driver has no assets. Your UM/UIM coverage pays up to your policy limits because the other driver has zero coverage. Without UM/UIM, you pay out of pocket or sue a driver who can't pay.
- A driver sideswiped your car on I-95 and fled. You have $6,000 in vehicle damage and $4,000 in medical bills. Your uninsured motorist property damage coverage pays for the vehicle damage, and your uninsured motorist bodily injury coverage pays for medical bills, up to your policy limits. The other driver is never identified, so their insurance never enters the picture.
- You're hit by a driver with Connecticut's minimum liability limits of $25,000 per person. Your medical bills are $40,000. Their liability insurance pays $25,000. Your underinsured motorist coverage pays the remaining $15,000, up to your UM/UIM limit. If you rejected UM/UIM, you're responsible for the $15,000 gap.
Who Needs Uninsured and Underinsured Motorist Coverage Insurance?
You should carry UM/UIM coverage if you drive regularly in Connecticut, especially on highways or in areas with high uninsured driver rates. It's critical if you have significant medical expenses that health insurance won't cover, or if you can't afford to pay out of pocket for vehicle damage and medical bills after a crash. Connecticut's requirement to offer it at your liability limits reflects the state's recognition that uninsured and underinsured drivers are common enough to justify mandatory offering.
Compare the cost of UM/UIM to the financial impact of a crash with an uninsured driver. If $18,000 in uncovered medical bills or $9,000 in vehicle damage would create financial hardship, the $96 to $216 annual cost is justified. If your health insurance and collision coverage already handle those scenarios and you're comfortable covering any remaining gaps, you can reject UM/UIM in writing.
How Much Does Uninsured and Underinsured Motorist Coverage Insurance Cost?
UM/UIM coverage typically adds $8 to $18 per month to a Connecticut auto insurance premium, or approximately $96 to $216 annually.
- Your UM/UIM limits — higher limits cost more, and Connecticut allows you to select limits up to your liability limits.
- Whether you stack coverage across multiple vehicles on the same policy, which increases the total available coverage and the premium.
- Your ZIP code and county — areas with higher rates of uninsured drivers see higher UM/UIM premiums.
- Your claims history with UM/UIM — prior uninsured motorist claims can increase future premiums.
- Whether you select uninsured motorist property damage coverage separately or rely on collision coverage for vehicle damage.