UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 10-Q (Mark One) ☒ Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the quarterly period ended September 30, 2023 Or ☐ 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: 000-10436 L.B. Foster Company (Exact name of registrant as specified in its charter) Pennsylvania 25-1324733 (State of Incorporat ...