ID S1118

Defines "uninsured motor vehicle" for uninsured motorist coverage to include insured vehicles whose liability insurers cannot make payment due to insolvency.

Defines "underinsured motor vehicle" for underinsured motorist coverage as a vehicle with liability limits at least equal to those set forth in section 49-117, Idaho Code.

Specifies that underinsured motorist coverage issued or renewed on or after July 1, 2021 is excess coverage that may not be reduced by amounts paid by the tortfeasor's coverage or other coverage.

Limits recovery under underinsured motorist policies to the lesser of the tortfeasor's total legal liability or the applicable underinsured coverage limits.

Authorizes the department of insurance to promulgate rules to implement and enforce the underinsured motorist coverage provisions, while preserving existing policy terms and conditions except as modified by the amendment.