The anti-aggregation provisions are intended to avoid applying multiple sets of deductibles or multiple sets of limits to a single loss event. They are sometimes included in insurance policies that cover risks that may occur over long periods of time, resulting in multiple policy coverage. They provide that in such a case only one policy limit or one deductible applies to the event (and not a limit or deductible per policy). Stacking Prevention Provisions (or Stacking Provisions) may be addressed in state vehicle insurance laws for Uninsured Motorists (UM)/Uninsured Motorists (UIM). These provisions vary greatly from one state to another; and if state legislators or the judiciary have considered the issue, statewide UM/UIM endorsements are often modified to reflect the state’s position on the issue.