(a) No change shall be made in any schedule, including schedules of joint rates, except upon thirty (30) days notice to the commission, and approval by the commission, and all such changes shall be plainly indicated upon existing schedules or by filing new schedules in lieu thereof thirty (30) days prior to the time the same are to take effect. The commission may prescribe a shorter time within which a change may be made. A public, municipally owned, or cooperatively owned utility may not file a request for a general increase in its basic rates and charges within fifteen (15) months after the filing date of its most recent request for a general increase in its basic rates and charges, except that the commission may order a more timely increase if:

1. (1) the requested increase relates to a different type of utility service;
2. (2) the commission finds that the utility's financial integrity or service reliability is threatened; or

3. (3) the increase is based on:

   1. (A) a rate structure previously approved by the commission; or

   2. (B) orders of federal courts or federal regulatory agencies having jurisdiction over the utility.

      The phrase "general increase in basic rates and charges" does not include changes in rates related solely to the cost of fuel or to the cost of purchased gas or purchased electricity or adjustments in accordance with tracking provisions approved by the commission. In addition to other tracking provisions the commission finds appropriate, the commission may approve periodic tracking mechanisms for water utilities and wastewater utilities to permit recovery of changes in property taxes. The commission may also approve periodic tracking mechanisms calculated to recover from customers located within the geographic boundaries of local units of government the incremental costs of operation and maintenance of water utilities and wastewater utilities resulting from policies or ordinances that are adopted by those local units and that the commission determines to be unusual but not necessarily unreasonable under section 101 of this chapter. The commission shall adopt rules under IC 4-22-2 to define what is unreasonable with respect to road cut permits and other specifications or policies established by a local unit that imposes costs on water or wastewater utilities.

(d) An electric generating utility may apply for a change in its fuel charge not more often than each three (3) months. When such application is filed the petitioning utility shall show to the commission its cost of fuel to generate electricity and the cost of fuel included in the cost of purchased electricity, for the period between its last order from the commission approving fuel costs in its basic rates and the latest month for which actual fuel costs are available. The petitioning utility shall also estimate its average fuel costs for the three (3) calendar months subsequent to the expiration of the twenty (20) day period allowed the commission in subsection (b). The commission shall conduct a formal hearing solely on the fuel cost charge requested in the petition subject to the notice requirements of IC 8-1-1-8 and shall grant the electric utility the requested fuel cost charge if it finds that:

1. (1) the electric utility has made every reasonable effort to acquire fuel and generate or purchase power or both so as to provide electricity to its retail customers at the lowest fuel cost reasonably possible;
2. (2) the actual increases in fuel cost through the latest month for which actual fuel costs are available since the last order of the commission approving basic rates and charges of the electric utility have not been offset by actual decreases in other operating expenses;
3. (3) the fuel adjustment charge applied for will not result in the electric utility earning a return in excess of the return authorized by the commission in the last proceeding in which the basic rates and charges of the electric utility were approved. However, subject to section 42.3 of this chapter, if the fuel charge applied for will result in the electric utility earning a return in excess of the return authorized by the commission, in the last proceeding in which basic rates and charges of the electric utility were approved, the fuel charge applied for will be reduced to the point where no such excess of return will be earned; and

4. (4) the utility's estimate of its prospective average fuel costs for each such three (3) calendar months are reasonable after taking into consideration:

   1. (A) the actual fuel costs experienced by the utility during the latest three (3) calendar months for which actual fuel costs are available; and
   2. (B) the estimated fuel costs for the same latest three (3) calendar months for which actual fuel costs are available.

(g) No schedule of rates, tolls, and charges of a public, municipally owned, or cooperatively owned gas utility that includes or authorizes any changes in charges based upon gas costs is effective without the approval of the commission except those rates, tolls, and charges contained in schedules that contain specific provisions for changes in gas costs or the cost of gas that have previously been approved by the commission. Gas costs or cost of gas may include the gas utility's costs for gas purchased by it from pipeline suppliers, costs incurred for leased gas storage and related transportation, costs for supplemental and substitute gas supplies, costs incurred for exploration and development of its own sources of gas supplies and other expenses relating to gas costs as shall be approved by the commission. Changes in a gas utility's rates, tolls, and charges based upon changes in its gas costs shall be made in accordance with the following:

1. (1) Before the commission approves any changes in the schedule of rates, tolls, and charges of a gas utility based upon the cost of the gas, the utility consumer counselor may examine the books and records of the public, municipally owned, or cooperatively owned gas utility to determine the cost of gas upon which the proposed changes are based. In addition, before such an adjustment to the gas cost charge becomes effective, the commission shall hold a summary hearing on the sole issue of the gas cost adjustment. The utility consumer counselor shall conduct the utility consumer counselor's review and make a report to the commission within thirty (30) days after the utility's request for the gas cost adjustment is filed. The commission shall hold the summary hearing and issue its order within thirty (30) days after it receives the utility consumer counselor's report. The provisions of this section and sections 39, 43, 54, 55, 56, 59, 60, and 61 of this chapter concerning the filing, printing, and changing of rate schedules and the time required for giving notice of hearing and requiring publication of notice do not apply to such a gas cost adjustment or such a summary hearing.
2. (2) Regardless of the pendency of any request for a gas cost adjustment by any gas utility, the books and records pertaining to cost of gas of all public, municipally owned, or cooperatively owned gas utilities shall be examined by the utility consumer counselor not less often than annually. The utility consumer counselor shall provide the commission with a report as to the examination of said books and records within a reasonable time following said examination. The utility consumer counselor may, if appropriate, request of the commission a reduction or elimination of the gas cost adjustment. Upon such request, the commission shall hold a hearing forthwith in the manner provided in sections 58, 59, and 60 of this chapter.

3. (3) A gas utility may apply for a change in its gas cost charge not more often than each three (3) months. When such application is filed, the petitioning utility shall show to the commission its cost of gas for the period between its last order from the commission approving gas costs in its basic rates and the latest month for which actual gas costs are available. The petitioning utility shall also estimate its average gas costs for a recovery period of not less than the three (3) calendar months subsequent to the expiration of the thirty (30) day period allowed the commission in subdivision (1). The commission shall conduct a summary hearing solely on the gas cost adjustment requested in the petition subject to the notice requirements of IC 8-1-1-8 and may grant the gas utility the requested gas cost charge if it finds that:

   1. (A) the gas utility has made every reasonable effort to acquire long term gas supplies so as to provide gas to its retail customers at the lowest gas cost reasonably possible;
   2. (B) the pipeline supplier or suppliers of the gas utility has requested or has filed for a change in the costs of gas pursuant to the jurisdiction and procedures of a duly constituted regulatory authority;
   3. (C) the gas cost adjustment applied for will not result, in the case of a public utility, in its earning a return in excess of the return authorized by the commission in the last proceeding in which the basic rates and charges of the public utility were approved; however, subject to section 42.3 of this chapter, if the gas cost adjustment applied for will result in the public utility earning a return in excess of the return authorized by the commission in the last proceeding in which basic rates and charges of the gas utility were approved, the gas cost adjustment applied for will be reduced to the point where no such excess of return will be earned; and

   4. (D) the utility's estimate of its prospective average gas costs for each such future recovery period is reasonable and gives effect to:

      1. (i) the actual gas costs experienced by the utility during the latest recovery period for which actual gas costs are available; and
      2. (ii) the actual gas costs recovered by the adjustment of the same recovery period.
4. (4) Should the commission at any time determine that an emergency exists that could result in an abnormal change in gas costs, it may, in order to protect the public or the utility from the adverse effects of such change suspend the provisions of subdivision (3) as to the utility or utilities affected by such an emergency and initiate such procedures as may be necessary to protect both the public and the utility from harm. The commission shall lift the suspension when it is satisfied the emergency no longer exists.

5. (5) Any change in the gas cost charge granted by the commission under the provisions of this section shall be reflected in the rates charged by the utility in the same manner as any other changes in rates granted by the commission in a case approving the basic rates and charges of the utility. However, the utility may file the change as a separate amendment to its rate schedules with a reasonable reference in the amendment that such charge is applicable to all of its filed rate schedules.

   Formerly: Acts 1913, c.76, s.45; Acts 1975, P.L.75, SEC.1. As amended by Acts 1979, P.L.85, SEC.4; P.L.43-1983, SEC.9; P.L.115-1987, SEC.1; P.L.108-1995, SEC.1; P.L.136-2018, SEC.44; P.L.61-2022, SEC.1; P.L.93-2024, SEC.63.