AEP: 10-Q financial filing

aep-20260930 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For The Quarterly Period Ended September 30, 2026 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For The Transition Period from ____ to ____ Commission Registrants; I.R.S. Employer File Number Address and Telephone Number States of Incorporation Identification Nos. 1-3525 AMERICAN ELECTRIC POWER CO INC. New York 13-4922640 333-221643 AEP TEXAS INC. Delaware 51-0007707 333-217143 AEP TRANSMISSION COMPANY, LLC Delaware 46-1125168 1-3457 APPALACHIAN POWER COMPANY Virginia 54-0124790 1-3570 INDIANA MICHIGAN POWER COMPANY Indiana 35-0410455 1-6543 OHIO POWER COMPANY Ohio 31-4271000 0-343 PUBLIC SERVICE COMPANY OF OKLAHOMA Oklahoma 73-0410895 1-3146 SOUTHWESTERN ELECTRIC POWER COMPANY Delaware 72-0323455 1 Riverside Plaza, Columbus, Ohio 43215-2373 Telephone (614) 716-1000 Securities registered pursuant to Section 12(b) of the Act: Registrant Title of each class Trading Symbol Name of Each Exchange on Which Registered American Electric Power Company Inc. Common Stock, $6.50 par value AEP The NASDAQ Stock Market LLC Indicate by check mark whether the registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. Yes x No ☐ Indicate by check mark whether the registrants have submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of