CHARLES RIVER LABORATORIES INTERNATIONAL, INC.

During the quarter ended September 26, 2026, none of our officers or directors adopted orterminated any contract, instruction, or written plan for the purchase or sale of our securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act or any “non-Rule 10b5-1 trading arrangement” as defined in Item 408(c) of Regulation S-K, except as follows:

•On August 13, 2026, Birgit Girshick, our Chief Executive Officer, terminated two 10b5-1 trading plans. One of the terminated plans was due to expire on August 31, 2026. The other terminated plan was due to become effective on September 1, 2026. The termination of the 10b5-1 trading plans occurred during an open trading window and complied with the Company’s policies on insider trading. Ms. Girshick terminated the plans in order to adopt a new 10b5-1 trading plan with limit orders at higher specified prices.

•On August 18, 2026, Ms. Girshick adopted a new 10b5-1 trading plan. The adoption of such 10b5-1 trading plan occurred during an open trading window and complied with the Company’s policies on insider trading. The first trade will not occur until November 20, 2026, at the earliest. Ms. Girshick’s plan is for the sale of up to (i)14,000 shares of our common stock and (ii)10,814 shares of common stock underlying stock options, based on limit orders at a specified price in accordance with the plan and terminates on the earlier of the date all the shares under the plan are sold or September 1, 2027.

•On August 27, 2026, Nancy Andrews, one of ourdirectors, adopted a 10b5-1 trading plan. The adoption of such 10b5-1 trading plan occurred during an open trading window and complied with the Company’s policies on insider trading. The first trade will not occur until November 26, 2026, at the earliest. Dr. Andrew’s plan is for the sale of up to 2,539 shares of common stock underlying stock options, based on limit orders at a specified price in accordance with the plan and terminates on the earlier of the date all the shares under the plan are sold or November 30, 2027.

•On August 28, 2026, Victoria Creamer, our Chief People Officer, adopted a 10b5-1 trading plan. The adoption of such 10b5-1 trading plan occurred during an open trading window and complied with the Company’s policies on insider trading. The first trade will not occur until November 27, 2026, at the earliest. Ms. Creamer’s plan is for the sale of up to 12,996 shares of common stock underlying stock options, based on limit orders at a specified price in accordance with the plan and terminates on the earlier of the date all the shares under the plan are sold or August 31, 2027.