In unemployment insurance (UI) in the United States, the average high-cost multiple (AHCM) is a commonly used actuarial measure of Unemployment Trust Fund adequacy. Technically, AHCM is defined as reserve ratio (i.e., the balance of UI trust fund expressed as % of total wages paid in covered employment) divided by average cost rate of three high-cost years in the state's recent history (typically 20 years or a period covering three recessions, whichever is longer). In this definition, cost rate for any duration of time is defined as benefit cost divided by total wages paid in covered employment for the same duration, usually expressed as a percentage.