AMENDMENT NO. 6 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Waystar Holding Corp. TABLE OF CONTENTS As filed with the U.S. Securities and Exchange Commission on May 16, 2024. Registration No. 333-275004 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Delaware (State or other jurisdiction of incorporation or organization) 7373 (Primary Standard Industrial Classification Code Number) 84-2886542 (I.R.S. Employer Identification No.) 1550 Digital Drive, #300 Lehi, ...