Administrative Rules of Montana
Department 38 - PUBLIC SERVICE REGULATION
Chapter 38.5 - UTILITY DIVISION
Subchapter 38.5.28 - Minimum Rate Case Filing Requirements for Telephone Utilities
Rule 38.5.2803 - ANALYSIS OF TOTAL SYSTEM COSTS FOR A TWELVE MONTH HISTORICAL TEST YEAR

(1) The application shall contain an analysis of total Montana costs as reflected on the filing utility's books for a test period consisting of 12 months actual experience ending no earlier than 9 months prior to the date of the filing of the application to increase rates. Any proposed adjustments to book costs shall be explained in writing. Such adjustments to book costs shall be shown separately and shall be fully supported, including schedules showing their derivation, where appropriate. However, no adjustments shall be permitted unless based on changes in facilities, operations, or costs which are known with certainty and measurable with reasonable accuracy at the time of the filing. No adjustment will be entertained unless it will become effective within 12 months of the last month of the test period.