Premium that is not a part of a loss sensitive rating formula. In a retrospective rating plan, the excess premium usually purchases the excess insurance (over the selected loss limits, not to be confused with insurance in excess of primary coverage or a self-insured retention). The excess premium is a guaranteed cost premium and not adjustable based on losses. In a retrospective rating premium plan, the excess premium is not subject to the retrospective rating formula. See also Non-subject premium, a related concept.