NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

You are hereby invited to attend the 2026 Annual Meeting of shareholders of CoastalSouth Bancshares, Inc.

YOUR VOTE IS IMPORTANT

TABLE OF CONTENTS

PROXY STATEMENT AND ANNUAL MEETING SUMMARY

General

The Board of Directors is sending this Proxy Statement (this “Proxy Statement”) to our shareholders to solicit proxies from holders of our voting common stock, $1.00 par value per share (our “Voting Common Stock”), for use at the Annual Meeting of the Shareholders (the “Annual Meeting”). Unless otherwise clearly specified, all references in this Proxy Statement to “CoastalSouth,” “we,” “us,” “our,” and the “Company” refer to CoastalSouth Bancshares, Inc.

Date, Time and Place of the Annual Meeting

CoastalSouth Bancshares, Inc.’s 2026 Annual Shareholders’ Meeting will be held on Thursday, April 23, 2026, beginning at 8:00 a.m., Eastern Time, at 400 Galleria Pkwy, Suite 1900, Atlanta, Georgia, 30339.

Record Date and Mailing Date

The close of business on March 5, 2026 is the record date (the “Record Date”) for the determination of shareholders entitled to notice of and to vote at the Annual Meeting. Only the holders of our outstanding Voting Common Stock as of the close of business on the Record Date will be entitled to notice of and to vote at the Annual Meeting. The Notice of Electronic Delivery is being mailed to such shareholders on or around March 13, 2026.

Summary of Proposals

The proposals to be considered at the meeting are summarized as follows:

Proposal 1. To elect eleven directors each to serve a one-year term ending at the Annual Meeting of Shareholders in 2027.

Proposal 2. To ratify the appointment of Elliott Davis, LLC as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2026.

Number of Shares Outstanding

As of the close of business on the Record Date, the Company had 50,000,000 shares of common stock authorized, of which 11,853,258 shares of voting common stock and 132,156 shares of nonvoting common stock were outstanding. As of the Record Date, the Company's voting common stock was held by 407 shareholders of record, including Cede & Co., as nominee for The Depository Trust Company, which holds shares held by our beneficial shareholders whose shares were held in "street name" through a broker, bank or other intermediary.

Requirements for Shareholder Approval

To hold a vote on any proposal, other than to adjourn the Annual Meeting for the lack of a quorum, a quorum must be present with respect to the proposal. A quorum will be present at the Annual Meeting if a majority of the outstanding shares of voting common stock entitled to vote at the Annual Meeting is represented in person or by valid proxy. We will count abstentions and broker non-votes, which are described below, as present in determining whether a quorum exists.

Vote Required. The holders of shares of CoastalSouth’s voting common stock are entitled to one vote per share on all matters presented at the Annual Meeting for action by shareholders. With respect to Proposal 1, for a director nominee to be elected, each director nominee must receive more affirmative votes for his seat on the Board of Directors than any other nominee for such seat. The Board of Directors is not aware of any competing nominees. With respect to Proposal 2, the ratification of Elliot Davis, LLC as the Company's independent public accounting firm requires the votes cast FOR the ratification exceed the votes cast AGAINST the ratification.

Abstentions. A shareholder who is present in person or by proxy at the Annual Meeting and who abstains from voting on any or all proposals will be included in the number of shareholders present at the Annual Meeting for purposes of determining the presence of a quorum. Abstentions do not count as votes for or against a given matter. An abstention will have no effect on the outcome of Proposal 1 or 2.

Broker Non-Votes. On certain “routine” matters, brokerage firms have discretionary authority under applicable stock exchange rules to vote their customers’ shares if their customers do not provide instructions. When a brokerage firm votes its customers’ shares on a “routine” matter without receiving instructions (referred to as a “broker vote”), these shares are counted both for establishing a quorum to conduct business at the Annual Meeting and in determining the number of shares voted “FOR” or “AGAINST” the “routine” matter. For purposes of the Annual Meeting, Proposal 2 (the ratification of the appointment of Elliot Davis, LLC as our independent registered public accounting firm for 2026) is considered a “routine” matter.

Under applicable stock exchange rules, Proposal 1: the election of directors, is considered a “non-routine” matter for which brokerage firms do not have discretionary authority to vote their customers’ shares if their customers did not provide instructions (referred to as a “broker non-vote”). Therefore, for purposes of the 2026 Annual Meeting, if you hold your stock through a brokerage account, your brokerage firm may not vote your shares on your behalf on Proposal 1 without receiving instructions from you. Broker non-votes are only counted for establishing a quorum, but will not be counted as votes cast either in favor of or against a non-routine proposal. If a quorum is present, broker non-votes will have no effect on the outcome of Proposal 1.

Procedures for Voting by Proxy

If you properly execute and deliver and do not revoke your proxy, the persons appointed as proxies will vote your shares according to the instructions you have specified on the proxy card. If you execute your proxy but do not provide your proxies with any instructions, then your shares will be voted “FOR” Proposal 1 and in accordance with the best judgment of the persons appointed as proxies as to all other matters properly brought before the Annual Meeting. No proxy marked specifically “WITHHOLD,” “ABSTAIN” or "AGAINST" with respect to any Proposal will be voted in favor of any other Proposal unless the proxy is specifically marked “FOR” such other Proposal.

A shareholder who has given a proxy may revoke it at any time prior to its exercise at the Annual Meeting by:

All written notices of revocation and other communications concerning proxies should be addressed to Stephen R. Stone, Chief Executive Officer of CoastalSouth Bancshares, Inc., at 400 Galleria Pkwy, Suite 1900, Atlanta, Georgia, 30339.

Solicitation of Proxies

CoastalSouth will pay the cost of proxy solicitation, if necessary. Our directors, officers and employees may, without additional compensation, solicit proxies by personal interview, telephone, fax or otherwise. We will direct brokerage firms or other custodians, nominees or fiduciaries to forward our proxy solicitation materials to the beneficial owners of voting common stock held of record by these institutions. We will reimburse these firms, custodians, nominees and fiduciaries for the reasonable out-of-pocket expenses that they incur in connection with this process.

MATTERS TO COME BEFORE THE ANNUAL MEETING

Ernst W. Bruderer. Mr. Bruderer has an extensive background serving as CEO for various industries. He is the Chairman of the Executive Committee and a Member of the Board of Directors of SYNCO Properties in Charlotte, NC and Chairman Elect of The Global Network Foundation in Atlanta. He also is a founder of CoastalSouth Bancshares, Inc. and Coastal States Bank where he serves as the Chairman of the Nominating and Governance Committee. He volunteers as a Facilitator for the Central Eurasia Leadership Alliance and the Middle East Leadership Alliance, representing SIBF (Society of International Business Fellows). Mr. Bruderer has a Bachelor of Arts degree in Business and Economics from the University of St. Gall and a Juris Doctor from the University of Zurich. He also attended Post-Graduate LLM Classes at Georgetown Law School. We believe Mr. Bruderer is qualified to serve on our Board of Directors due to his extensive business and leadership experience.

Patrick M. Frawley. Mr. Frawley serves as Vice-Chairman of the Board of Directors of CoastalSouth Bancshares, Inc. and Coastal States Bank. Mr. Frawley was the founder of Community & Southern Bank, a bank for which he served as the Chief Executive Officer before retiring in 2016. He has served in a variety of key regulatory roles with the Comptroller of the Currency and has held numerous positions with multinational banks. Mr. Frawley is a graduate of Campbell University and Louisiana State University’s School of Banking. We believe that Mr. Frawley is qualified to serve on our Board of Directors due to his background in leading growing strong community banking franchises, as well as the unique perspective on the challenges and opportunities for our organization he can offer based on his regulatory background.

J. Simon Fraser. Mr. Fraser is a Partner in the law firm of Fraser and Allen, LLC, whose primary legal work areas include real estate and business law, covering commercial and residential real estate, business transaction, and general matters regarding corporations, partnerships and limited liability companies. He has served on numerous boards and commissions, particularly in the Hilton Head Island area, including serving as the Chairman of the Heritage Classic Foundation and Vice Chairman of the Beaufort-Jasper Commission on Higher Education. Mr. Fraser has a Bachelor of Arts from the University of Virginia and his Juris Doctor from the University of South Carolina. Mr. Fraser is a founder of CoastalSouth Bancshares, Inc. and Coastal States Bank and has served on the Board of Directors of Coastal States Bank since 2003. He was elected to the Board of Directors of CoastalSouth Bancshares, Inc, in February of 2026. We believe Mr. Fraser is qualified to serve on our Board of Directors due to his business background and extensive community involvement.

Mark A. Griffith. Mr. Griffith is a retired Managing Director and Director of Real Estate for LNR Partners Europe Ltd. where he was responsible for operations and directing investments strategies across the U.K. and Western Europe before retiring in 2009. He also served as Vice President of three U.S. commercial real estate companies specializing in retail shopping centers and office building ownership, development, and management. Mr. Griffith attended Ohio University. We believe Mr. Griffith is qualified to serve on our Board of Directors due to his financial background and expertise in running and growing complex real estate operations.

Michael B. High. Mr. High is a retired Partner of Patriot Financial Partners L.P. Prior to joining Patriot Financial Partners, Mr. High was a finance executive at a number of financial institutions including Harleysville National Corporation and Progress Financial Corporation. He currently is a Member of the Board of Directors of DR Bank. Mr. High is a CPA (Inactive) and a graduate of The Pennsylvania State University. We believe Mr. High is qualified to serve on our Board of Directors due to his financial leadership background at a number of community banking institutions and his experience in investing in community banking institutions.

James N. Richardson, Jr. Mr. Richardson is Chairman and CEO of The Richardson Group whose holdings include Coligny Plaza, Windmill Harbour Company, the South Carolina Yacht Club, Windmill Harbour Real Estate, and multiple other developments such as Westbury Park, Compass Commons at New River, Barony at Port Royal, and work force housing. The Richardson Group’s restaurant division include Local Pie Hilton Head, Bluffton and New Riverside, and Fish Coastal Seafood. Mr. Richardson serves as a Commissioner of the South Island Public Service District and has chaired and served on numerous boards that benefit the Lowcountry and South Carolina. Mr. Richardson is a founder of CoastalSouth Bancshares, Inc. and Coastal States Bank and has served on their Boards of Directors since 2003. Mr. Richardson is a graduate of Mars Hill College. We believe Mr. Richardson is qualified to serve on our Board of Directors due to his extensive business background and deep community involvement, which provide substantial insights for our business operations.

Stephen R. Stone. Mr. Stone is the President and Chief Executive Officer of CoastalSouth Bancshares, Inc. and Coastal States Bank. Prior to joining the Bank in 2017, he served as the Chief Strategy Officer and General Counsel of Community & Southern Bank. In addition to serving as a member of the Board of Directors of CoastalSouth and CSB, Mr. Stone is a member of the Board of Directors of Coastal States Mortgage, Inc. as well as a member of the Board of Directors of The Buckhead Coalition. Mr. Stone is a graduate of the University of Virginia, and he received his Juris Doctor from the Washington College of Law at American University, cum laude. We believe that Mr. Stone is qualified to serve on our Board of Directors due to his extensive knowledge of the banking industry, mergers and acquisitions, and strong leadership skills, which provide the board with invaluable insight and guidance into the business and regulatory requirements of today’s banking environment.

Joseph V. Topper, Jr. Mr. Topper has served as the Chief Executive Officer of Dunne Manning Inc. and Affiliates since 1992. He has 34 years of management experience in the wholesale and retail fuel distribution business. Mr. Topper is Chairman of the Board of CrossAmerica Partners LP, is a Member of the Board of Directors of PBS39 public television and is a Member of the Board of Pool Trust. He has been the past chair of trustees of Villanova University. He is a graduate of Villanova University, and he received a Master of Business Administration from Lehigh University. We believe that Mr. Topper is qualified to serve on our Board of Directors due to his extensive business experience and community involvement, which provides us with insight into the economic and business operations in our core markets.

Director Qualifications

We believe that our directors should have the highest professional and personal ethics and values, consistent with our longstanding values and standards. They should have broad experience at the policy-making level in areas relevant to our business. They should be committed to enhancing shareholder value and should have sufficient time to carry out their duties and to provide insight and practical wisdom based on their own unique experience. Each director must represent the interests of all shareholders. When considering potential director candidates, our Board of Directors also considers the candidate’s independence, character, judgment, diversity of background, age, skill-sets, financial literacy, specific business background and global or international experience in the context of our needs and those of the Board of Directors. Our Board of Directors’ priority in selecting board members is the identification of persons who will further the interests of our shareholders through his or her record of professional and personal experiences and expertise relevant to our growth strategy. The following matrix depicts the diversity of experience of our Board of Directors.

In furtherance of the foregoing, the Board considers a wide range of attributes when selecting and recruiting candidates. Our nominees have executive experience and skills that are aligned with our business and strategy as follows:

Director Independence

New York Stock Exchange ("NYSE") listing standards require that a majority of our directors be independent and that each member of our Audit Committee, Nominating and Governance Committee, and Compensation Committee be independent. Our Board determines the independence of each director and director nominee in accordance with guidelines it adopted, which include all elements of independence set forth in the NYSE listing standards and U.S. Securities and Exchange Commission (“SEC”) rules. The Board first considers whether any director or nominee has a relationship covered by the NYSE listing standards that prohibits an independence finding for Board or committee purposes. Any director who has a material relationship with CoastalSouth or its management is not considered to be independent.

Our Board has affirmatively determined that all of our director nominees are independent, except for our President and CEO, Mr. Stone, due to his employment with the Company.

Our Board determined as to each independent director that no relationship exists which, in the opinion of the Board, would interfere with the exercise of the director’s independent judgment in carrying out his or her responsibilities as a director. The Board also determined that each person who currently serves or who served in 2025 on the Audit Committee, the Nominating and Governance Committee, or the Compensation Committee meets or met, as applicable, the NYSE independence requirements for membership on those committees and, as to the Audit Committee, SEC independence rules.

In reaching the determination that Mr. Aldridge is independent, the Board considered that during 2025, CoastalSouth paid approximately $125,000 to the law firm of Aldridge | Pite, LLP for various legal services. Mr. Aldridge is a partner with Aldridge | Pite, LLP. The fees paid to Aldridge | Pite, LLP by CoastalSouth during 2025 amount to less than 0.13% of that firm’s total revenue and did not exceed established thresholds that are incompatible with Mr. Aldridge being considered independent under the rules of NYSE and applicable provisions of the Securities Exchange Act of 1934 (the “Exchange Act”). Mr. Aldridge performed no legal work for the Company and received no compensation related to any engagement with the Company.

Retirement policy

The Board of Directors recently adopted an amendment to our Corporate Governance Guidelines requiring a non-management director to offer not to stand for re-election in each calendar year following a year in which the director will be 75 or older. The Board (other than the affected director) then determines whether to accept the offer. This retirement age policy will become effective at the 2027 Annual Meeting. The Board believes that the appropriate mix of experience and fresh perspectives is an important consideration in assessing Board composition, and the best interests of the Company are served by taking advantage of all available talent, and evaluations as to director candidacy should not be determined solely on age.

Four of our current directors will be 75 or older this year. We expect to make a deliberate and thoughtful transition as we implement this new policy.

Board Meetings

The Board conducts its business as a group and through a well-developed committee structure in adherence to strong corporate governance principles. The Board has established practices and processes to actively manage its information flow, set meeting agendas and make sound, well-informed decisions.

Board members have direct access to management and regularly receive information from and engage with management during and outside of formal Board meetings. The full Board met 13 times in 2025. Each director attended 75% or more of the total meetings of the Board during his or her time as a Board member during 2025, except for Mr. High, who was present for 9 of the 13 meetings.

RECOMMENDATION OF THE BOARD OF DIRECTORS

THE BOARD OF DIRECTORS UNANIMOUSLY

RECOMMENDS A VOTE FOR THE ELECTION OF EACH NOMINEE UNDER PROPOSAL 1

CORPORATE GOVERNANCE AND THE BOARD OF DIRECTORS

General

We conduct business through meetings of our Board of Directors and its committees. The Board of Directors of the Company has established standing committees, including an Audit Committee, Compensation Committee, a Nominating and Governance Committee and a Credit and Risk Committee. Each of these committees operates under a written charter, which governs its composition, responsibilities and operations. A copy of each charter is available on the Company’s website at https://www.coastalstatesbank.com/ by choosing the menu "About" and selecting the “Investor Relations” link then clicking on the “Corporate Governance” section. Our Board of Directors also may establish such other committees as it deems appropriate, in accordance with applicable law and regulations and our corporate governance documents.

Board Leadership Structure

The Board reviews its leadership structure annually as part of its Board and committee self-evaluation process, which is overseen by the Nominating and Governance Committee. This evaluation includes consideration of emerging corporate governance trends and peer practices, to help ensure the Board's structure remains aligned with the interests of the Company and its shareholders.

The Board does not currently designate a Lead Independent Director since the Chairman of the Board is independent. To promote independent oversight, the independent directors of the Board meet in executive session without management present on a periodic basis, as required under applicable NYSE governance rules. The Board has no current intention to alter this structure, which it believes provides stability, clarity of leadership, and effective oversight.

Each of the Company's standing committees are comprised entirely of independent directors. Each committee operates under a written charter, and the respective Chairs have the authority to convene executive sessions without the presence of management or non-independent directors. The Board and its committees maintain unrestricted access to senior management and have the authority to retain independent advisors, consultants, or counsel at the Company's expense, as they deem necessary to carry out their responsibilities. The non-management directors of the Board meet in regularly scheduled executive sessions without management present.

The Compensation Committee

The Compensation Committee is responsible for discharging the Board of Directors’ responsibilities relating to compensation of the executives and directors. Among other things, the Compensation Committee:

The Compensation Committee is composed solely of members who satisfy the applicable independence requirements of the SEC and the NYSE.

The Compensation Committee has the authority under its charter to retain outside consultants or advisors, as it deems necessary or advisable. In accordance with this authority, the Compensation Committee has engaged the services of FW Cook & Associates (“FW Cook”) as its independent outside compensation consultant to perform analyses and provide advice related to the Company’s executive and director compensation programs. All executive compensation services provided by FW Cook were conducted under the direction or authority of the Compensation Committee.

The Compensation Committee evaluated whether any services proposed to be performed during 2025 by FW Cook raised any conflict of interest and determined that it did not. Neither FW Cook nor any of its affiliates maintains any other direct or indirect business relationships with us or any of our subsidiaries. As requested by the Compensation Committee, FW Cook’s services to the Compensation Committee included, among other things, providing perspective on current trends and developments in executive and director compensation, as well as analysis of benchmarking data against peer companies for both executive and director compensation.

The Nominating and Governance Committee

The Nominating and Governance Committee (the “NGC”) is responsible for making recommendations to our Board of Directors regarding candidates for directorships and the size and composition of our Board of Directors. In addition, the NGC is responsible for overseeing our corporate governance guidelines and reporting and making recommendations to our Board of Directors concerning governance matters. Among other things, the NGC:

The NGC is composed solely of members who satisfy the applicable independence requirements of the SEC and the NYSE.

The Audit Committee

The Audit Committee assists the Board of Directors in fulfilling its responsibilities for general oversight of the integrity of our financial statements, compliance with legal and regulatory requirements, the independent registered public accounting firm’s qualifications and independence, and the performance of our internal audit and risk assessment function and the independent registered public accounting firm. Among other things, the Audit Committee:

The Audit Committee works closely with management as well as our independent registered public accounting firm. The Audit Committee has the authority to obtain advice and assistance from and receive appropriate funding to engage outside legal, accounting or other advisors as the Audit Committee deems necessary to carry out its duties.

The Audit Committee is composed solely of members who satisfy the applicable independence and other requirements of the SEC and the NYSE for Audit Committees and our Board of Directors has determined that Messrs. Griffith and High each qualify as an “audit committee financial expert” under applicable SEC rules.

The Credit and Risk Committee

The Credit and Risk Committee is responsible for discharging the Board of Directors’ responsibility in overseeing the enterprise-wide risk management practices of the Company, the Bank, and their respective subsidiaries, including management’s ability to assess and manage credit, market, interest rate, liquidity, reputation, strategic, legal, compliance, and operational risks (which includes information technology risk). Among other things, the Credit and Risk Committee:

The Credit and Risk Committee is composed solely of members who satisfy the applicable independence requirements of the SEC and the NYSE.

RELATED PARTY TRANSACTIONS

Policies and Procedures Regarding Related Party Transactions

Transactions by the Company with related parties are subject to a formal written policy, as well as certain regulatory requirements and restrictions, including Sections 23A and 23B of the Federal Reserve Act and the FRB’s Regulation W (which govern certain transactions by Coastal States Bank with its affiliates) and the FRB's Regulation O (which governs certain loans by Coastal States Bank to its executive officers, directors and principal shareholders). We have adopted policies to comply with these regulatory requirements and restrictions.

In addition, we have adopted a written policy governing the approval of related party transactions that complies with all applicable requirements of the SEC and NYSE rules. Related party transactions are transactions in which we are a participant, the amount involved exceeds $120,000 and a related party has or will have a direct or indirect material interest. Related parties of the Company include directors (including nominees for election as directors), executive officers, five percent shareholders and the immediate family members of these persons. In determining whether to approve a related party transaction, the Board of Directors will consider, among other factors, as it deems appropriate, the related party’s interest in the related party transaction, the approximate dollar value of the amount involved in the related party transaction, the approximate dollar value of the amount of the related party’s interests in the related party transaction without regard to the amount of any profit or loss, whether the related party transaction was undertaken in the ordinary course of business, whether the related party transaction with the related party is proposed to be, or was, entered into on terms no less favorable to the Company than terms that could have been reached with an unrelated third party, the purpose of, and the potential benefits to the Company of, the related party transaction, the fairness of the proposed transaction, the direct or indirect nature of the related party’s interest in the transaction, the appearance of an improper conflict of interests for any director or executive officer taking into account the size of the transaction and the financial position of the related party, whether the transaction would impair an outside director’s independence, the acceptability of the transaction to our regulators and the potential violations of other corporate policies, and any other information regarding the related party transaction or the related party in the context of the proposed related party transaction that would be material to investors in the light of the circumstances of the particular related party transaction.

Banking Relationships and Related Party Transactions

The Sarbanes-Oxley Act of 2002 generally prohibits publicly traded companies from making loans to their executive officers and directors, but it contains a specific exemption from the prohibition for loans made by federally insured financial institutions, such as Coastal States Bank, to their executive officers and directors in compliance with federal banking regulations. Applicable law and our written credit policies require that loans to insiders be on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with unrelated parties, and must not involve more than the normal risk of repayment or present other unfavorable features. Loans to non- insider employees and other non-insiders are subject to the same requirements and underwriting standards and meet our normal lending guidelines, except that non-insider employees and other non-insiders may receive preferential interest rates and fees as an employee benefit. Loans to individual employees, directors and executive officers must also

comply with our Bank’s statutory lending limits and regulatory requirements regarding lending limits and collateral. All extensions of credit to the related parties must be reviewed and approved by our Bank’s Board of Directors, and directors with a personal interest in any loan application are excluded from the consideration of such loan application. At December 31, 2025, all of our loans to directors and executive officers, including loans to current nominees, were made in compliance with our Regulation O policies and procedures, in the ordinary course of business, were made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable loans with persons not related to Coastal States Bank, and did not involve more than the normal risk of collectability or present other features unfavorable to us. These loans were performing according to their original terms at December 31, 2025, and were made in compliance with federal banking regulations.

At December 31, 2025, the aggregate amount of extensions of credit to our directors, executive officers, principal shareholders and their associates, including extensions of credits to our current nominees, was $2.4 million, or approximately 0.93% of our total shareholders' equity. At December 31, 2025, total unfunded commitments to these related parties were $7.0 million.

During 2025, CoastalSouth paid approximately $125,000 to the law firm of Aldridge | Pite, LLP for various legal services. Mr. Aldridge is a partner with Aldridge | Pite, LLP. The fees paid to Aldridge | Pite, LLP by CoastalSouth during 2025 amount to approximately 0.13% of that firm’s total revenue and did not exceed established thresholds that are incompatible with Mr. Aldridge being considered independent under the rules of NYSE and applicable provisions of the Exchange Act. Mr. Aldridge performed no legal work for the Company and received no compensation related to any engagement with the Company.

Hemby worked at PricewaterhouseCoopers, LLP, in the firm’s financial services assurance practice. She is a Certified Public Accountant, licensed in the State of Georgia, and holds both bachelor’s and master’s degrees in Accountancy from Wake Forest University.

(1) The amounts reported here do not reflect the actual economic value realized by each named executive officer. In accordance with SEC rules, the Stock Awards column reflects the grant date fair value of restricted stock unit (RSU) awards, calculated in accordance with ASC 718. For additional information, see Note 13 in our Annual Report on Form 10-K as of December 31, 2025 filed with the SEC.

(2) All Other Compensation for 2025 includes the following:

Narrative Disclosure to Summary Compensation Table

Base Salaries. Annual base salaries for Messrs. Stone and Valduga were $576,118 and $370,397, respectively, for 2024, and for Mr. Stone, Mr. Valduga and Ms. Hemby were $617,333, $380,936 and $241,397, respectively, for 2025. The Compensation Committee reviews and establishes the base salary of Mr. Stone on an annual basis. The Compensation Committee relies upon compensation benchmarking provided by FW Cook, the Compensation Committee’s independent compensation consultant, as well as data from Aon’s Human Capital Solutions practice, a division of Aon, PLC (“Aon”) otherwise known as McLagan. Specifically, the Company incorporates a peer-based approach in our executive compensation program to align compensation with performance. Competitive compensation data from peer companies is used as a reference point for making decisions about overall executive compensation and specific compensation components. We also consider distinct circumstances not reflected in the peer data, such as unique job descriptions or responsibilities, and the impact that a particular officer may have on our ability to meet our goals.

Non-Equity Incentive Plan. Our named executive officers are eligible to receive an annual bonus, as described below.

The threshold, target, and maximum payout levels for our NEOs as a percentage of salary for the fiscal year ended December 31, 2025, as approved by the Compensation Committee, are set forth in the table below.

The Compensation Committee reviewed performance against performance criteria for 2025, including earnings per share, efficiency ratio, and credit metrics, and determined to award bonuses as reflected in the Non-Equity Incentive Plan column of the Summary Compensation table. Individual awards are based upon both objective scorecard metrics, as well as subjective individual performance.

Equity Incentive Plans. In April 2025, the Board and our shareholders approved the CoastalSouth Bancshares, Inc. Omnibus Incentive Plan (the “Omnibus Plan”) to promote the success, and enhance the value of the Company by linking the personal interests of employees, officers, directors and consultants of the Company or any affiliate to those of our shareholders and by providing such persons with an incentive for outstanding performance. The Omnibus Plan is further intended to provide flexibility to the Company in its ability to motivate, attract and retain the services of employees, officers, directors and consultants upon whose judgment, interest, and special

effort the successful conduct of the Company’s operation is largely dependent. The Compensation Committee believes that the Omnibus Plan provides a competitive incentive opportunity for our executive leadership, and aligns executive pay with shareholder value creation, while maintaining a focus on risk management and Company soundness.

For 2025 equity awards, the Compensation Committee utilized a plan design consistent with the plan design utilized in 2024. In establishing the total targeted dollar value of the awards to each of the NEOs in 2025, the Compensation Committee considered competitive market data, including relevant peer data. Additionally, the Compensation Committee considered the Company’s overall performance, individual performance and extraordinary contributions, and potential future contributions. On January 17, 2025, each of our NEOs received RSUs that vest 100% on the fifth anniversary of the grant date, subject to his or her continued employment on each such vesting date. RSUs will become fully vested upon the NEO’s death or disability or a change in control.

401(k) Plan. The Bank maintains defined contribution plan under which eligible employees may elect to defer a portion of their compensation and receive certain employer contributions (the “401(k) Plan”). The named executive officers are eligible to participate in the 401(k) Plan on the same terms as other eligible employees of the Bank. Eligible employees are immediately enrolled into the 401(k) Plan.

Under the 401(k) Plan, a participant may elect to defer, on a pretax basis, a portion of their eligible compensation. For 2025, the salary deferral contribution limit is $23,500, provided, however, that a participant over age 50 may contribute an additional $7,500 to the 401(k) Plan, for a total of $31,000. In addition to salary deferral contributions, the Bank makes matching contributions up to 5% of the participant’s compensation. A participant is immediately 100% vested in his or her salary deferral contributions. The participant will not vest on the Bank’s matching contribution until after 2 years of service with the Bank. Participants become vested in employer discretionary nonelective contributions to the 401(k) Plan pursuant to a six-year graded vesting schedule. Participants become vested in these contributions at a rate of 20% per year beginning in year two.

Health and Welfare Benefits. Our named executive officers are eligible to participate in the same benefit plans designed for all of our eligible full-time and part-time employees, including medical, dental, vision, disability and basic group life insurance coverage. In addition, pursuant to the terms of their employment agreements (which are described below), Mr. Stone and Mr. Valduga are entitled to be reimbursed for group health, dental, and welfare benefit plans offered by the Bank.

Perquisites. We provide our named executive officers with a limited number of perquisites that we believe are reasonable and consistent with our overall compensation program to better enable us to attract and retain superior employees for key positions. Our Compensation Committee periodically reviews the levels of perquisites and other personal benefits provided to named executive officers.

Limit on Compensation Payable to Non-Employee Directors. With respect to any one calendar year, the aggregate compensation that may be granted to any non-employee director, including all meeting fees, cash retainers and retainers granted in the form of awards, may not exceed $100,000, or $125,000 in the case of a non-employee Chairman of the Board or Lead Director. For purposes of such limit, the value of awards will be determined based on the aggregate grant date fair value of all awards issued to the director in such year (computed in accordance with applicable financial accounting rules).

Employment Agreements

We are party to executive employment agreements with each of Messrs. Stone and Valduga. The agreements have an initial three-year term and renew automatically every year for one year thereafter, unless notice of non-renewal is provided by either party. Under the agreements Mr. Stone’s 2025 base salary was $617,333 and Mr. Valduga’s 2025 base salary was $380,936. In addition to base salary, Messrs. Stone and Valduga are eligible to participate in the annual cash incentive plan and equity award plan. The Bank will also reimburse Messrs. Stone and Valduga for the full cost for group health and dental plans as well as up to five hundred dollars ($500) per month towards participation in other welfare benefits plans offered by the Bank. Messrs. Stone and Valduga are also eligible to participate in all incentive, savings and retirement plans, practices, policies and programs available to the other senior officers of the Bank. All reasonable travel and other business expenses incurred by Messrs. Stone and Valduga in the performance of their duties are reimbursed by the Bank in accordance with its reimbursement policy, as amended from time to time.

(1) RSUs granted in 2023 cliff vest on the third anniversary of the grant date, RSUs granted in 2024 and 2025 cliff vest on the fifth anniversary of the grant date and in each case subject to the NEO’s continued service on such date (with certain exceptions).

(2) Market value is calculated on the basis of $23.25 per share, which was the closing sales price for our common stock as reported on the NYSE on December 31, 2025.

Potential Payments Upon Termination of Employment or Change in Control

Messrs. Stone and Valduga. Pursuant to Messrs. Stone and Valduga employment agreements, in the event of their termination by the Bank without cause (as defined in the agreement) or their resignation for good reason (as defined in the agreement) (in either case, a “qualifying termination”), the executive will receive a severance payment equal to 1.50 times the sum of (1) the executive’s base salary in effect as of the date of termination and (2) the average of his annual bonuses for the preceding 3 years. The executive would also receive an additional cash payment equal to the pro-rata portion of his annual cash bonus for the year during which his qualifying termination occurred. In addition, the Bank shall pay the excess cost of COBRA beyond what the executive would have to pay for such coverage under the Bank’s health and welfare plan until the earlier of (1) the date on which he first becomes eligible for health insurance with another employer, or (2) the period that Mr. Stone would be entitled to coverage under COBRA.

In the event of a qualifying termination upon or within 18 months of a change in control of the Company, the agreement provides that the executive will be entitled to a change in control severance payment equal to 2.99 times the sum of (1) the executive’s base salary in effect as of the date of termination and (2) the average of his annual bonuses for the preceding 3 years. The agreement provides that gross payments due to the executive in the event of a change in control will be reduced to avoid an excess parachute payment under Section 280G of the Code if the effect would be to deliver a greater after-tax benefit than the employee would receive with an unreduced benefit.

The agreement requires compliance with a one-year non-competition covenant inside certain restricted territories and a one-year non-solicitation covenant related to employees and customers.

Ms. Hemby. Ms. Hemby participates in the Bank’s Executive Severance Plan (the “Executive Severance Plan”), which provides severance benefits to designated participants under certain circumstances, subject to the participant’s execution of a general release of claims and compliance with restrictive covenants. Pursuant to the Executive Severance Plan, in the event of Ms. Hemby’s termination by the Bank without cause (as defined in the Executive Severance Plan) or her resignation for good reason (as defined in the Executive Severance Plan) (in either case, a “qualifying termination”), other than in connection with a change in control, Ms. Hemby will receive severance in an amount equal to twenty-five percent (25%) of her annual base salary, payable in approximately equal installments over a 3-month period in accordance with the Bank’s regular payroll practices. If such qualifying termination occurs within twelve (12) months following a change in control, Ms. Hemby will receive, instead, a lump sum payment equal to 1.5 times the sum of (i) her base

salary in effect as of the date of termination and (ii) the average of her annual bonuses for the preceding three years, payable in a single lump sum within sixty (60) days following termination. The Executive Severance Plan requires compliance with a one-year non-competition covenant inside certain restricted territories and a one-year non-solicitation covenant related to employees and customers. The Executive Severance Plan provides that gross payments due to the executive in the event of a change in control will be reduced to avoid an excess parachute payment under Section 280G of the Code.

Executive Compensation Policies

Prohibitions on Hedging. The Company prohibits all directors, officers and employees from engaging in speculative trading and hedging shares of Company securities. This includes prohibitions against short-selling Company securities and transactions in any derivative of Company securities, including buying and writing options. Directors, officers and employees are restricted from buying Company securities on margin or using Company securities as collateral for a loan. Additionally, the Company’s Insider Trading Policy prohibits trading for directors, officers and certain employees during designated blackout periods and requires approval by the Company’s Chief Executive Officer or Chief Financial Officer prior to any trade.

Clawback Policy. The Company maintains a clawback policy that complies with the applicable listing standards of the NYSE Listing Company Manual Section 303A.14 and Rule 10D-1 under the Securities Exchange Act of 1934, as amended. In the event of a restatement of the reported financial results of the Company due to material non-compliance with financial reporting requirements, the Compensation Committee will recover reasonably promptly the amount of all erroneously awarded compensation received by an executive officer during the covered period (within the meaning of such terms as provided in the NYSE listing standards).

Policies and Practices Regarding Timing of Equity Grants. Our Compensation Committee, in its discretion, typically makes the annual grants to qualifying individuals in the first quarter of each year. Such awards are based upon each team members' performance during the preceding year. From time to time, our Compensation Committee may approve supplemental or other non-recurring grants outside of our annual compensation program. While we do not have a formal written policy in place with regard to the timing of awards of equity in relation to the disclosure of material nonpublic information, the Compensation Committee does not seek to time equity grants to take advantage of information, either positive or negative, about our Company that has not been publicly disclosed.

We also offer reimbursements to our directors for their reasonable out-of-pocket expenses, including travel and lodging, incurred in attending meetings of our Board of Directors and Committees.

STOCK OWNERSHIP

director or executive officer may be deemed to have sole or shared voting and/or dispositive powers. The holders may disclaim beneficial ownership of the included shares which are owned by or with family members, trusts or other entities.

(2) Based on 11,853,258 shares of our common voting as of March 5, 2026 plus the inclusion of nonvoting common stock where applicable plus the number of shares issuable to such individual upon the exercise of stock options or upon the vesting of restricted stock units within the next 60 days.

(3) The address of each director and executive officer is: c/o CoastalSouth Bancshares, Inc. 400 Galleria Parkway, Suite 1900, Atlanta, GA 30339

(4) Included in the shares beneficially owned by the directors and executive officers are options to purchase shares of the Company’s common stock which are currently exercisable or which will become exercisable within 60 days after March 5, 2026, as follows: Mr. Frawley - 15,000 shares; Mr. MacLeod - 55,000 shares; Mr. Stone - 129,000 shares; Mr. Valduga - 113,000 shares; Ms. Hemby - 42,500 shares; and all directors and officers as a group - 354,500 shares.

(5) Included in the shares beneficially owned by the directors and executive officers are restricted stock units of the Company’s common stock which are currently become vested within 60 days after March 5, 2026, as follows: Mr. Stone - 17,000 shares; Mr. Valduga - 13,000 shares; Ms. Hemby - 4,000 shares; and all directors and officers as a group - 34,000 shares.

(6) Shares beneficially owned include 375,226 shares held by Dunne Manning Investments, LP (“DMI”). DMI’s voting and dispositive power is held by Dunne Manning GP, LLC. Joseph V. Topper, Jr. currently serves as the representative of DMI on our Board of Directors. Shares beneficially owned also include 31,250 shares held by The Topper Foundation.

(7) Patriot Financial Partners II Coastal SPV, LLC II is the holder of record of 1,151,311 shares of voting common stock and 132,156 of non-voting common stock. Patriot Financial Manager, LP is the holder of record of 7,900 shares of voting common stock. Patriot Financial Partners II Coastal SPV, LLC’s voting and dispositive power is held by Patriot Financial Partners II GP, L.P. (“Patriot II GP”), which is the general partner of Patriot Financial Partners II Coastal SPV, LLC and by Patriot Financial Partners II GP, LLC (“Patriot II LLC”), which is the general partner of Patriot II GP, and by W. Kirk Wycoff, Ira M. Lubert, and James J. Lynch who serve as the general partners of the funds and Patriot II GP and as the members of Patriot II LLC. Patriot Financial Manager’s voting and dispositive power is held by Patriot Financial Manager GP LLC (“Manager GP”) and by W. Kirk Wycoff, Ira M. Lubert and James J. Lynch who serve as members of Manager GP. Mr. Wycoff, Mr. Lubert, and Mr. Lynch each disclaim beneficial ownership of such shares of Voting Common Stock, except to the extent of their respective pecuniary interest in the funds. The ownership percentage assumes that all such shares of non-voting common stock have been converted into common stock.

(8) Based on a Schedule 13G filed by Fourthstone LLC and its related entities further described (collectively "Fourthstone") with the SEC on February 13, 2026, Fourthstone holds 959,797 shares with shared voting power and shared dispositive power. Of these shares, Fourthstone Master Opportunity Fund LTD holds 748,448 shares. Fourthstone GP LLC holds 211,349 shares as the general partner for both Fourthstone QP Opportunity Fund, which holds 196,246 of these shares, and Fourthstone Small-Cap Financials Fund LP, which holds 15,103 of these shares. L. Philip Stone, IV, is the managing member of Fourthstone with shared voting and dispositive power for all 959,797 shares.

(9) GCP Capital Partners LLC is the holder of record of 7,900 shares of voting common stock and GCP CoastalSouth LLC is the holder of record of 902,002 shares of voting common stock (collectively "GCP"). GCP Capital Partners IV, L.P and GCP Capital Partners (Cayman) IV, L.P. own 98% and 2% respectively of GCP CoastalSouth LLC. GCP's voting and dispositive power is held by its general partner, GCP Managing Partner IV GP, and GCP's Investment Committee.