TABLE OF CONTENTS As filed with the U.S. Securities and Exchange Commission on April 29, 2024. Registration No. 333-275004 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 5 TO 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. Emp ...