The underinsured motorist coverage limits trigger is one of the two triggers that can be specified by an insured party to protect against losses caused by an accident with a driver who has insufficient insurance.

The underinsured motorist coverage limits trigger ensures coverage in the event of an accident caused by a driver with inadequate insurance, and when the underinsured driver's liability limit is lower than that of the insured person or policyholder. The other trigger for underinsured motorist coverage is known as the damages or coverage trigger.