Equitable treatment for all members can be achieved only if members whose career patterns covering the same time frame and who received identical annual salaries during each of the twelve-month periods of that time frame accrue the same monthly service retirement allowance. To achieve this equity for the member whose annual salary has been paid on other than a twelve-month salary schedule during any contractual or like twelve-month period, the average monthly salary used for each one of those twelve-month periods will be determined from the total base period salary by using a divisor representing the months of membership service which would have been accumulated at that rate over a full base period.
Idaho Admin. Code r. 59.01.01.525