Idaho PUC Vacates Comment Deadlines for Avista Rate Increase

ORDER NO. 36964 1 Office of the Secretary Service Date March 16, 2026 BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION IN THE MATTER OF AVISTA CORPORATION’S APPLICATION TO INCREASE ITS SCHEDULE 91 ENERGY EFFICIENCY TARIFF RIDER ADJUSTMENT ) ) ) ) ) ) ) ) ) ) CASE NO. AVU-E-26-01 ORDER VACATING COMMENT DEADLINES AMENDED NOTICE OF MODIFIED PROCEDURE ORDER NO. 36964 On February 13, 2026, Avista Corporation, dba Avista Utilities (“Company”) applied to the Idaho Public Utilities Commission (“Commission”) requesting authority to increase its I.P.U.C. No. 28, Schedule 91, “Energy Efficiency Rider Adjustment” rates by approximately 7.4%, effective May 1, 2026. On March 5, 2026, the Commission issued a Notice of Application and Notice of Modified Procedure establishing written comment deadlines. Order No. 36953. At the Commission’s March 12, 2026, Decision Meeting, upon further consideration of the procedural schedule and the amount of the Company’s requested rate increase, Commission Staff (“Staff”) submitted a memo recommending we vacate and reset the comment deadlines to provide additional time for public input. The Commission now issues this Order Vacating Comment Deadlines and Amended Notice of Modified Procedure reestablishing written comment deadlines. YOU ARE HEREBY NOTIFIED that the Commission has determined that the public interest may not require a formal hearing in this matter, and that it will proceed under Modified Procedure pursuant to the Commission’s Rules of Procedure 201-204, IDAPA 31.01.01.201-.204. The Commission notes that Modified Procedure and written comments have proven to be an effective means for obtaining public input and participation. YOU ARE FURTHER NOTIFIED that persons desiring to state a position on this Application may file a written comment explaining why the person supports or opposes the

ORDER NO. 36964 2 Application. Persons who would like a hearing must specifically request a hearing in their written comments and explain why written comments alone are insufficient. Persons interested in filing written comments must do so by April 10, 2026. Comments must be filed through the Commission’s website or by e-mail unless computer access is unavailable. To comment electronically, please access the Commission’s website at http://www.puc.idaho.gov/. Click the “Case Comment Form” and complete the form using the case number as it appears on the front of this document. To file by e-mail, persons must e-mail the comments to the Commission Secretary and all parties at the e-mail addresses listed below. Persons submitting a comment by e-mail must provide their name, address, and the Case Number under which they are commenting. Persons submitting a comment by e-mail also acknowledge that submitting a comment in an open case constitutes a public record under Idaho Code § 74-101(13), and all information provided by such person is available for public and media inspection. If computer access is unavailable, then comments may be mailed to the Commission and the Parties at the addresses below. Persons submitting a comment by mail must provide their name, address, and the Case Number under which they are commenting. Persons submitting a comment by mail also acknowledge that submitting a comment in an open case constitutes a public record under Idaho Code § 74-101(13), and all information provided by such person is available for public and media inspection. For the Idaho Public Utilities Commission: Commission Secretary Idaho Public Utilities Commission P.O. Box 83720 Boise, ID 83702-0074 secretary@puc.idaho.gov For the Company: Anni Glogovac Shawn Bonfield Avista Corporation P.O. Box 3727, MSC 33 1411 E. Mission Avenue Spokane, WA 99220-3727 anni.glogovac@avistacorp.com shawn.bonfield@avistacorp.com AvistaDockets@avistacorp.com YOU ARE FURTHER NOTIFIED that the Company must file any reply comments by April 17, 2026.

ORDER NO. 36964 3 YOU ARE FURTHER NOTIFIED that if no written comments or protests are received within the time limit set, the Commission will consider this matter on its merits and enter its final order without a formal hearing. If written comments are received within the time limit set, the Commission will consider them and, in its discretion, may set the same for formal hearing. ORDER IT IS HEREBY ORDERED that the comment deadlines established in Order No. 36953 are vacated. IT IS FURTHER ORDERED that this Application be processed under Modified Procedure. Persons interested in submitting written comments must do so by April 10, 2026. The Company must file any reply comments by April 17, 2026. IT IS FURTHER ORDERED that parties comply with Order No. 35375, issued April 21, 2022. Generally, all pleadings should be filed with the Commission electronically and will be deemed timely filed when received by the Commission Secretary. See Rule 14.02. Service between parties should continue to be accomplished electronically when possible. However, voluminous discovery-related documents may be filed and served on CD-ROM or a USB flash drive. DONE by Order of the Idaho Public Utilities Commission at Boise, Idaho this 16 th day of March 2026. _________________________________________ EDWARD LODGE, PRESIDENT __________________________________________ JOHN R. HAMMOND JR., COMMISSIONER __________________________________________ DAYN HARDIE, COMMISSIONER ATTEST: Monica Barrios-Sanchez Commission Secretary I:\Legal\ELECTRIC\AVU-E-26-01EER\orders\AVUE2601vacmodjl.docx