• Class 1 insurers is a term sometimes used in the context of uninsured motorists (UM) and underinsured motorists (UIM) coverage to refer to the specified insured person and family members of the specified insured person (as opposed to all other insured persons referred to as a class) . 2 insurers). Class 1 policyholders may be provided with broader coverage than class 2 policyholders, especially with regard to cumulative limits.