WILLIAM KIRBY LAW LLC

ntributions equal to 100 % of the employee’s contribution, up to 3 % of the employee’s considered compensation. Each participant directs his or her contributions and the Company’s matching contributions between the investment funds offered by the Plan, including Company common stock. Vessel based employees of Kirby Offshore Marine, LLC (“KOM”) whose employment is covered by collective bargaining agreements receive a non-discretionary employer match and may receive a discretionary employer contribution based on the terms of the applicable collective bargaining agreement. The Plan allows the employer, at its discretion, to make an additional employer discretionary contribution for eligible employees equal to 5 % of the employees’ considered compensation. Eligible employees include employees

utions of the account relating to employer contributions could be paid as periodic payments or lump sum payments. Participants who reached the age of 55 and had completed six full years of vesting service were entitled to withdraw all vested amounts from his or her Profit Sharing account. Profit Sharing accounts are not available for a loan. The Plan requires automatic distribution of participant accounts upon termination without the participant’s consent of amounts less than $ 5,000 and greater than $ 1,000 . If the participant does not elect to have the amount paid directly to an eligible retirement plan or receive a distribution directly, then the Plan will pay the distribution to an individual retirement plan designated by the Plan Administrator. Amounts less than $ 1,000 are paid dire

es from non-vested accounts of $ 2,173,357 and $ 1,992,488 were used to reduce the Plan’s matching contributions in 2025 and 2024, respectively. All employees hired or rehired are automatically enrolled at a 3 % pretax contribution rate, unless otherwise elected by the participant. In addition, participants may contribute amounts representing rollovers from other qualified plans or from an individual retirement arrangement. (d) Benefits Benefit payments are made to participants upon retirement or termination of employment (or to the beneficiary in the event of death) and are in the form of lump sum or installment distribution payments. A participant may request a loan for up to the lesser of 50 % of the participant’s vested interest or $ 50,000 , less the participant’s highest outstanding

lar agreements. Forfeitures in the amount of $ 365,520 and $ 192,586 as of December 31, 2025 and 2024, respectively, were available to offset future employer contributions or plan administrative expenses at the discretion of the Company. (f) Plan Termination Although it has not expressed any intent to do so, the Company has the right under the Plan to terminate the Plan subject to the provisions of ERISA. In the event of termination, the amounts credited to the accounts of participants will be distributed to the participants after payment of expenses for distribution and liquidation. (g) Participant Accounts Under the Plan, each participant’s account is credited with the participant’s contribution, the Company’s matching contribution, the Company's discretionary contribution, the Company's