The address of the principal business and principal office of each of TCP, TCM, TM, TCP 2, TAA, TA and TCO is 1 Sound Shore Drive, Suite 304, Greenwich, Connecticut 06830. The business address of Mr. Gendell is 1 Sound Shore Drive, Suite 304, Greenwich, Connecticut 06830.

The principal business of each of TCP and TCP 2 is serving as a private investment limited partnership. The principal business of TCM is serving as the general partner of TCP. The principal business of TM is serving as the general partner of an investment fund affiliated with the Reporting Persons. The principal business of TAA is serving as the general partner of TCP 2. The principal business of TA is to serve as the fund manager of an investment fund affiliated with the Reporting Persons. The principal business of TCO is that of managing its assets. Mr. Gendell serves as the managing member of TCM, TM, TA, TCO and TAA.

None of the Reporting Persons has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

None of the Reporting Persons has, during the last five years, been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and, as a result of such proceeding, was, or is subject to, a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, Federal or State securities laws or finding any violation with respect to such laws.

Each of TCP and TCP 2 is a limited partnership organized under the laws of the State of Delaware. Each of TCM, TM, TAA, TA and TCO is a limited liability company organized under the laws of the State of Delaware. Mr. Gendell is a United States citizen.

All securities of the Company owned by the Reporting Persons were purchased with working capital and on margin or, with respect to certain securities owned directly by Mr. Gendell, were granted to Mr. Gendell by the Company for service as a member of the Company's Board of Directors, in connection with his service as the Company's Executive Chairman, or in connection with his service as the Company's Chief Executive Officer pursuant to the IES Holdings, Inc. 2006 Equity Incentive Plan as amended and restated through February 20, 2025 (the "Equity Incentive Plan"). The securities of the Company owned by the Reporting Persons that were purchased on margin are all currently held in cash accounts.

On October 5, 2026, in connection with the closing of the Company's acquisition of DBM Global, Inc., the Company issued 430,974 shares of Common Stock as part of the consideration for such acquisition, resulting in 40,279,686 shares of Common Stock outstanding, based on 39,848,712 shares outstanding as of July 27, 2026, as disclosed in the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2026 filed on July 31, 2026 (as adjusted to reflect the two-for-one forward stock split of the Company's Common Stock effected on August 21, 2026). As a result of this increase in the Company's outstanding shares of Common Stock, the percentage of the Company's outstanding shares of Common Stock beneficially owned by the Reporting Persons as a group decreased from approximately 53.2%, as reported in Amendment No. 32 to Schedule 13D filed by the Reporting Persons on January 9, 2026, to approximately 51.7%, as reported in this Amendment No. 33 to Schedule 13D. None of the Reporting Persons has effected any transactions in the Company's Common Stock in the last 60 days. The Reporting Persons acquired their shares of Common Stock for investment purposes and in the ordinary course of business or, with respect to certain of the shares of Common Stock and the PSUs owned directly by Mr. Gendell, through grants to Mr. Gendell by the Company for service as a member of the Company's Board of Directors, in connection with his service as the Company's Executive Chairman, or in connection with his service as the Company's Chief Executive Officer pursuant to the Equity Incentive Plan. All of the Reporting Persons may dispose of securities of the Company at any time and from time to time in the open market, through dispositions in kind to parties holding an ownership interest in TCP, TCM, TM, TA, TCP 2, TAA and/or TCO, or otherwise. In addition, the Reporting Persons may obtain securities of the Company through open market purchases, transfers from other Reporting Persons, grants to Mr. Gendell pursuant to the Equity Incentive Plan or otherwise. As discussed in this Schedule 13D, the Reporting Persons own approximately 51.7% of the Company's outstanding Common Stock and can control the Company's affairs, including (i) the election of directors who in turn appoint management, (ii) any action requiring the approval of the holders of Common Stock, including the adoption of amendments to the Company's corporate charter, and (iii) approval of a merger or sale of all or substantially all assets. The Reporting Persons can also control certain decisions affecting the Company's capital structure. Mr. Gendell has served as a member of the Company's Board of Directors and as Chairman of the Board since November 2016, and as Executive Chairman of the Board since July 1, 2025. Mr. Gendell served as Interim Chief Executive Officer of the Company from July 31, 2020 through September 30, 2020 and served as Chief Executive Officer of the Company from October 1, 2020 through June 30, 2025. While serving in such capacities, Mr. Gendell may have the ability to affect the composition of the Company's management and influence the business operations of the Company or extraordinary transactions outside the normal course of the Company's business. If the Reporting Persons dispose of all or a portion of their holdings in the Company, they may not retain sufficient voting power to cause Mr. Gendell to continue to be a director. David B. Gendell, the brother of Jeffrey L. Gendell and, until December 2017, an employee of an affiliate of the Reporting Persons, has served as a member of the Company's Board of Directors since February 2012. Previously, he served as Interim Director of Operations from November 2017 through January 2019, non-executive Vice Chairman of the Board from November 2016 to November 2017 and as non-executive Chairman of the Board from January 2015 to November 2016. While serving in his capacity as a director, David B. Gendell may have the ability to affect the composition of the Company's management and influence the business operations of the Company or extraordinary transactions outside the normal course of the Company's business. If the Reporting Persons dispose of all or a portion of their holdings in the Company, they may not retain sufficient voting power to cause David B. Gendell to continue to be a director. Although the foregoing represents the range of activities presently contemplated by the Reporting Persons with respect to the Company, it should be noted that the possible activities of the Reporting Persons are subject to change at any time. Accordingly, the Reporting Persons reserve the right to change their plans or intentions and to take any and all actions that they may deem to be in their best interests. Except as set forth in this Schedule 13D, the Reporting Persons do not have any current intention, plan or proposal with respect to: (a) the acquisition by any person of additional securities of the Company, or the disposition of securities of the Company; (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Company or any of its subsidiaries; (c) a sale or transfer of a material amount of assets of the Company or any of its subsidiaries; (d) any change in the present Board of Directors or management of the Company, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the Board; (e) any material change in the present capitalization or dividend policy of the Company; (f) any other material change in the Company's business or corporate structure; (g) changes in the Company's charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Company by any person; (h) causing a class of securities of the Company to be delisted from a national securities exchange, if any, or cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) a class of equity securities of the Company becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Act, or (j) any action similar to any of those enumerated in items (a) through (i) above.

See rows 11 and 13 of the Reporting Persons section of this Schedule 13D/A, which are incorporated herein by reference, for the aggregate number of shares of Common Stock and the percentage of shares of the Common Stock beneficially owned by each of the Reporting Persons. The percentages used herein are calculated based upon 40,279,686 shares of Common Stock outstanding, consisting of (i) 39,848,712 shares outstanding as of July 27, 2026, as disclosed in the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2026 filed on July 31, 2026 (as adjusted to reflect the two-for-one forward stock split of the Company's Common Stock effected on August 21, 2026), and (ii) 430,974 shares of Common Stock issued by the Company as stock consideration in connection with the Company's acquisition of DBM Global, Inc., which closed on October 5, 2026, as disclosed in a Form 8-K filed by the Company on October 6, 2026 in connection with the consummation of such acquisition.

See rows 7 through 10 of the Reporting Persons section of this Schedule 13D/A, which are incorporated herein by reference, for the number of shares of Common Stock as to which each Reporting Person has the sole or shared power to vote or direct the vote and the sole or shared power to dispose or to direct the disposition.

None of the Reporting Persons has effected any transactions in the Company's Common Stock in the last 60 days.

TCM, the general partner of TCP, has the power to direct the affairs of TCP, including decisions respecting the receipt of dividends from, and the disposition of the proceeds from the sale of, shares of Common Stock. Mr. Gendell is the Managing Member of TCM and in that capacity directs its operations. TAA, the general partner of TCP 2, has the power to direct the affairs of TCP 2, including decisions respecting the receipt of dividends from, and the disposition of the proceeds from the sale of, shares of Common Stock. Mr. Gendell is the Managing Member of TAA and in that capacity directs its operations. Mr. Gendell is the Managing Member of TM and in that capacity directs its operations. Mr. Gendell is the Managing Member of TA and in that capacity directs its operations. Mr. Gendell is the Managing Member of TCO and in that capacity directs its operations.

Not applicable.

A. Board Observer Letter On December 6, 2018, TA entered into that certain Board Observer Letter Agreement, by and between TA and the Company (the "Board Observer Letter"). Subject to the terms and conditions set forth in the Board Observer Letter, the Company granted the Reporting Persons the right, at any time that the Reporting Persons hold at least 20% of the outstanding Common Stock of the Company, to appoint a representative to serve as an observer to the Company's Board of Directors (the "Board Observer"). The Board Observer, who must be reasonably acceptable to those members of the Company's Board of Directors who are not affiliates of TA, shall have no voting rights or other decision-making authority. Subject to the terms and conditions set forth in the Board Observer Letter, so long as the Reporting Persons have the right to appoint a Board Observer, the Board Observer will have the right to attend and participate in meetings of the Company's Board of Directors and the committees thereof, subject to confidentiality requirements, and to receive reimbursement for reasonable out-of-pocket expenses incurred in his or her capacity as a Board Observer and such rights to coverage under the Company's directors' and officers' liability insurance policy as are available to the Company's directors. On December 20, 2018, an employee of TA was appointed as TA's initial Board Observer pursuant to the terms of the Board Observer Letter. B. Letter Agreement On October 2, 2020, the Company and Mr. Gendell entered into an amended and restated letter agreement (the "Letter Agreement") to memorialize Mr. Gendell's appointment, effective October 1, 2020, as Chief Executive Officer of the Company. Pursuant to the Letter Agreement, among other things, the Company made a one-time grant of 100,000 PSUs to Mr. Gendell under the Company's Equity Incentive Plan in connection with Mr. Gendell's appointment as Chief Executive Officer of the Company, which PSUs are subject to certain vesting conditions. The terms of such grant are further described in the Phantom Stock Unit Award Agreement attached as Exhibit A to the Letter Agreement. The foregoing summaries of the Board Observer Letter and the Letter Agreement do not purport to be complete and are qualified in their entirety by reference to Exhibits 99.1 and 99.2, which are incorporated by reference herein. Except as described herein, the Reporting Persons do not have any contracts, arrangements, understandings or relationships (legal or otherwise) with any person with respect to any securities of the Company, including but not limited to, the transfer or voting of any of the securities, finder's fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or losses, or the giving or withholding of proxies.

99.1. Board Observer Letter Agreement, between Tontine Associates, L.L.C. and IES Holdings, Inc., dated December 6, 2018 (incorporated by reference to Exhibit 10.17 to the Company's Annual Report on Form 10-K filed December 7, 2018). 99.2. Letter Agreement, between IES Holdings, Inc. and Jeffrey L. Gendell, dated October 2, 2020 (incorporated by reference to Exhibit 10.1 of the Company's Current Report on Form 8-K filed October 5, 2020).