There are two types of uninsured motorist coverage: Non-stacked and Stacked.
Non-stacked UM costs less than stacked UM. Non-stacked UM will cover you when you occupy the vehicles that are listed on that automobile insurance policy.
Stacked UM costs more than Non-stacked UM but it can provide higher policy limits. It covers you when you occupy the vehicles listed on your insurance policy and it will also cover you in cars that are not listed on the policy. Stacked UM will also cover you while riding motorcycles. The Stacked UM limit shown on your policy declaration page is multiplied based on the number of vehicles insured on your policy.
For example, if you have three cars insured on a policy with UM limits of $100,000 per person/$300,000 per accident, on a Non-stacked UM policy, $100,000/$300,000 would be the most you would be able to collect.
However, if you purchased Stacked UM coverage, you would multiply the limits by the number of vehicles insured under the policy, i.e. $100,000/$300,000 X 3 = $300,000/$900,000.