UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2023. ☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to . Commission file number 0-19969 ARCBEST CORPORATION (Exact name of registrant as specified in its charter) Delaware 71-0673405 (State or other jurisdiction of (I.R.S. Emplo ...