Catalyst Bancorp, Inc.

The Company has adopted a Statement of Policy and Procedures Governing Trading in Shares of Catalyst Bancorp, Inc. (“Insider Trading Policy”) which is reasonably designed to promote compliance with insider trading laws, rules and regulations, and standards of Nasdaq Capital Market. The Insider Trading Policy governs the purchase, sale and/or other disposition of the Company’s common stock by the Company’s directors, executive officers and all other Company and Bank personnel. An addition was made to the Insider Trading Policy on April 23, 2025, to clarify its applicability to the timing of the award of equity rights in securities of the Company, including but not limited to common stock, restricted stock, or stock options, to executives of the Company as compensation. The amended Insider Trading Policy can be found as Exhibit 19 to this Current Report on Form 10-Q.

During the fiscal quarter ended March 31, 2025, none of the Company’s directors orexecutive officers informed the Company of the adoption, modification, ortermination of anycontract, instruction or written plan for the purchase or sale of Company securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or anynon-Rule 10b5-1 trading arrangement.