MT SB290

Requires motor vehicle liability policies in Montana to include underinsured motorist coverage in addition to existing uninsured motorist coverage, with coverage limits matching those in section 61-6-103

Defines "underinsured motor vehicle" as a vehicle with liability insurance that is insufficient to cover the total damages an injured person is legally entitled to recover

Allows named insureds to reject underinsured motorist coverage in writing, with the rejection carrying forward to renewal policies unless the insured later requests coverage

Updates transportation network carrier (rideshare) insurance requirements to include underinsured motorist coverage for drivers while logged on to digital networks or engaged in prearranged rides