There are three types of Uninsured Motorist insurance; the first covers the insured party against damages caused by an uninsured driver. Therefore, if you get in an accident with an uninsured driver, your UM insurance will pay the damages, up to your policy limit, that the other driver’s liability insurance normally would have paid. But your Uninsured Motorist coverage will only pay out if you were not the party at fault.
The other two types of UM insurance deal with underinsured motorists. The first only pays out to the insured if his/her UM coverage is greater than that of the uninsured/underinsured driver’s liability insurance. For example, if you were involved in an accident and the at-fault driver had liability insurance in the amount of $75,000, but the damages caused to you amounted to $100,000, your UM insurance would not cover the excess unless you were carrying more than $75,000 in Uninsured Motorist coverage. The second type of UM insurance stacks with whatever liability insurance is available. If both you and the at-fault driver have $100,000 in coverage, your UM insurance is available to cover any costs above the $100,000 liability, up to your own $100,000 limit, for an aggregate of $200,000.