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fstr-202603030000352825FALSE00003528252026-03-032026-03-03

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) March 3, 2026

L.B. Foster Company (Exact name of registrant as specified in its charter)

Pennsylvania000-1043625-1324733 (State or other jurisdiction of incorporation)(Commission File Number)(I.R.S. Employer Identification No.)

415 Holiday Drive, Suite 100,15220 Pittsburgh,Pennsylvania(Zip Code) (Address of principal executive offices)

(412) 928-3400 (Registrant’s telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, Par Value $0.01FSTRNasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On March 3, 2026, L.B. Foster Company (“Company”) issued a press release announcing the Company’s results of operations for the fourth quarter and fiscal year ended December 31, 2025. A copy of that press release is furnished with this report as Exhibit 99.1.

The information contained in this Current Report shall not be deemed to be “filed” for the purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such filing.

Item 9.01     Financial Statements and Exhibits

(d)    Exhibits

See Exhibit Index below. Exhibit Index

Exhibit NumberDescription *99.1Press Release dated March 3, 2026, of L.B. Foster Company.

*104Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101)

*Exhibits marked with an asterisk are filed herewith.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

L.B. FOSTER COMPANY

(Registrant)

Date:March 3, 2026/s/ William M. Thalman William M. Thalman Executive Vice President and Chief Financial Officer (Duly Authorized Officer of Registrant)

fstr-202511030000352825FALSE00003528252025-11-032025-11-03

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) November 3, 2025

L.B. Foster Company (Exact name of registrant as specified in its charter)

Pennsylvania000-1043625-1324733 (State or other jurisdiction of incorporation)(Commission File Number)(I.R.S. Employer Identification No.)

415 Holiday Drive, Suite 100,15220 Pittsburgh,Pennsylvania(Zip Code) (Address of principal executive offices)

(412) 928-3400 (Registrant’s telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, Par Value $0.01FSTRNasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On November 3, 2025, L.B. Foster Company (“Company”) issued a press release announcing the Company’s results of operations for the third quarter ended September 30, 2025. A copy of that press release is furnished with this report as Exhibit 99.1.

The information contained in this Current Report shall not be deemed to be “filed” for the purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such filing.

Item 9.01     Financial Statements and Exhibits

(d)    Exhibits

See Exhibit Index below.

Exhibit Index

Exhibit NumberDescription *99.1Press Release dated November 3, 2025 of L.B. Foster Company.

*104Cover Page Interactive Data File (embedded within the Inline XBRL document)

*Exhibits marked with an asterisk are filed herewith.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

L.B. FOSTER COMPANY

(Registrant)

Date:November 3, 2025/s/ William M. Thalman William M. Thalman Executive Vice President and Chief Financial Officer (Duly Authorized Officer of Registrant)