UNITED STATES SECURITIES AND EXCHANGE COMMISSION FORM 10-K For the fiscal year ended  December 31, 2019 (Mark One) ☒  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 or ☐  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________ to_________ Securities registered pursuant to Section 12(b) of the Act: 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 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 New York Stock Exchange American Electric Power Company Inc. 6.125% Corporate Units AEP PR B New York Stock Exchange WASHINGTON, D.C. 20549