Waystar Holding Corp.

On November 27, 2024, Craig Bridge, our Chief Transformation Officer, adopted a trading plan intended to satisfy the affirmative defense conditions of Rule 10b5-1 (c) under the Exchange Act. Mr. Bridge’s plan provides for (i) the sale of up to 306,831 shares of previously issued common stock, (ii) the exercise of up to 232,925 vested stock options and the associated sale of up to 232,925 shares of the Company’s common stock, (iii) the exercise of up to 242,000 options with performance-based vesting conditions and the associated sale of shares of the Company’s common stock, with the actual number of such options and associated shares to be determined based on level of achievement of the performance criteria associated with the award, and (iv) the sale of up to 30,434 shares of the Company’s common stock issuable upon vesting of time-based vesting restricted stock units. Mr. Bridge’s trading plan will expire on October 31, 2025 or upon the earlier sale of all of the shares subject to the plan.

During the three months ended March 31, 2025, none of the Company’s directors or officers adopted, modified, or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” as each term is defined in Item 408 of Regulation S-K.