TABLE OF CONTENTS Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 As filed with the U.S. Securities and Exchange Commission on October 16, 2023. FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Waystar Holding Corp. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation or organization) 7373 (Primary Standard Industrial Classification Code Number) 84-2886542 (I.R.S. Employer Identification No ...