# EDGAR Filing Document

**Accession Number:** 0001600919
**File Stem:** 0001600919-26-000010
**Filing Date:** 2026-3
**Character Count:** 9095
**Document Hash:** de990051e8f9cfe59a3fbd2247428c35
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001600919-26-000010.hdr.sgml**: 20260309

**ACCESSION NUMBER**: 0001600919-26-000010

**CONFORMED SUBMISSION TYPE**: 4/A

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260219

**FILED AS OF DATE**: 20260309

**DATE AS OF CHANGE**: 20260309

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Guinee Patrick J.
- **CENTRAL INDEX KEY:** 0001600919

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-10436
- **FILM NUMBER:** 26734747

**MAIL ADDRESS:**
- **STREET 1:** 415 HOLIDAY DRIVE
- **STREET 2:** SUITE 100
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15220
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** FOSTER L B CO
- **CENTRAL INDEX KEY:** 0000352825
- **STANDARD INDUSTRIAL CLASSIFICATION:** WHOLESALE-METALS SERVICE CENTERS & OFFICES [5051]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 251324733
- **STATE OF INCORPORATION:** PA
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 415 HOLIDAY DR
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15220
- **BUSINESS PHONE:** 4129283431

**MAIL ADDRESS:**
- **STREET 1:** 415 HOLIDAY DR
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15220

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4/A

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Guinee Patrick J.<br><sub>(Last) (First) (Middle)</sub><br>L.B. FOSTER COMPANY<br>415 HOLIDAY DRIVE, SUITE 100<br><sub>(Street)</sub><br>PITTSBURGH, PA 15220<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-02-19 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_EVP General Counsel & Sec._ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>FOSTER L B CO [ FSTR ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-02-19 |  | A |  | 7170<sup>(1)</sup> | A | $0 | 88298<sup>(2)(3)(4)</sup> | D |  |
| Common Stock | 2026-02-19 |  | A |  | 3359<sup>(5)</sup> | A | $0 | 91657<sup>(3)(6)</sup> | D |  |
| Common Stock | 2026-02-19 |  | A |  | 1239<sup>(7)</sup> | A | $0 | 92896<sup>(3)(6)(8)</sup> | D |  |
| Common Stock | 2026-02-19 |  | A |  | 5613<sup>(9)</sup> | A | $0 | 98509<sup>(3)(6)(8)</sup> | D |  |
| Common Stock | 2026-02-19 |  | F |  | 10091<sup>(10)</sup> | D | $31.125 | 88418<sup>(6)(8)</sup> | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Represents the number of shares of common stock resulting from Performance Share Units earned under the 2023-2025 Long Term Incentive Plan granted on 2/14/2023 upon certification of performance results by the Compensation Committee at 47.2% for the annual period ended December 31, 2025.

(2) Includes 2,194 Performance Restricted Stock Units earned under the 2024-2026 Long Term Incentive Plan granted on 5/23/2024; those 2,194 Performance Restricted Stock Units will settle at the end of the performance period on December 31, 2026, upon certification by the Compensation Committee.

(3) Includes 23,044 shares of common stock resulting from the settlement of Performance Restricted Stock Units earned under the 2023-2025 Long Term Incentive Plan granted on 2/14/2023; those 23,044 Performance Restricted Stock Units settled at the end of the 2023-2025 performance period upon certification by the Compensation Committee on 2/19/2026.

(4) This amended Form 4 was filed to correct the number of shares beneficially owned to reflect the amendment made to the Form 4 originally filed on 2/18/2026.  The amendment to the Form 4 was filed on 3/09/2026 to correct the number of shares withheld to pay taxes applicable to the vesting of restricted stock on 2/14/2026.

(5) Represents the number of Performance Restricted Stock Units earned under the 2024-2026 Long Term Incentive Plan granted on 5/23/2024 upon certification of performance results by the Compensation Committee at 39.5% for the annual period ended December 31, 2025.  The earned Performance Restricted Stock Units will settle at the end of the performance period on December 31, 2026, upon certification by the Compensation Committee.

(6) Includes 5,553 Performance Restricted Stock Units earned under the 2024-2026 Long Term Incentive Plan granted on 5/23/2024; those 5,553 Performance Restricted Stock Units will settle at the end of the performance period on December 31, 2026, upon certification of the Compensation Committee.

(7) Represents the number of Performance Restricted Stock Units earned under the 2025-2027 Long Term Incentive Plan granted on 5/22/2025 upon certification of performance results by the Compensation Committee at 11.2% for the annual period ended December 31, 2025.  The earned Performance Restricted Stock Units will settle at the end of the performance period on December 31, 2027, upon certification by the Compensation Committee.

(8) Includes 1,239 Performance Restricted Stock Units earned under the 2025-2027 Long Term Incentive Plan granted on 5/22/2025; those 1,239 Performance Restricted Stock Units will settle at the end of the performance period on December 31, 2027, upon certification by the Compensation Committee.

(9) Award of restricted stock units (RSUs), which are settled in stock upon vesting, and generally will vest ratably over a three-year period on the first, second, and third anniversary of the date of grant.

(10) Shares withheld to pay taxes upon the vesting and settlement of all earned performance shares related to the 2023-2025 LTIP awarded on 2/14/2023.

**Signature:** /s/ Patrick J. Guinee by Judith Balog, attorney-in-fact  
**Date:** 2026-03-09

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**