SCHEDULE 13G/A 0001104659-24-117985 0001283718 XXXXXXXX LIVE 1 Common Stock 02/24/2025 0001990354 Waystar Holding Corp. 946784105 1550 Digital Drive #300 Lehi UT 84043 Rule 13d-1(d) Canada Pension Plan Investment Board Z4 0.00 29692286.00 0.00 29692286.00 29692286.00 N 17.2 FI Item 11 is calculated based on a total of 172,151,839 shares of common stock of the issuer outstanding as of February 12, 2025, as disclosed in the issuer's prospectus filed with the Securities and Exchange Commission on February 21, 2025. Shares reported on this Schedule 13G are held directly by CPP Investment Board Private Holdings (4) Inc., a wholly-owned subsidiary of Canada Pension Plan Investment Board. CPP Investment Board Private Holdings (4) Inc. Z4 0.00 29692286.00 0.00 29692286.00 29692286.00 N 17.2 CO Item 11 is calculated based on a total of 172,151,839 shares of common stock of the issuer outstanding as of February 12, 2025, as disclosed in the issuer's prospectus filed with the Securities and Exchange Commission on February 21, 2025. Shares reported on this Schedule 13G are held directly by CPP Investment Board Private Holdings (4) Inc., a wholly-owned subsidiary of Canada Pension Plan Investment Board. Waystar Holding Corp. 1550 Digital Drive #300 Lehi, UT, 84043 Canada Pension Plan Investment Board CPP Investment Board Private Holdings (4) Inc. One Queen Street East, Suite 2500, Toronto, Ontario M5C 2W5 Canada Canada (Federal) Y See Item 9 on pages 2 and 3. See Item 11 on pages 2 and 3. See Item 5 on pages 2 and 3. See Item 6 on pages 2 and 3. See Item 7 on pages 2 and 3. See Item 8 on pages 2 and 3. Y Y Y Y Y Y 99.1 Power of Attorney Canada Pension Plan Investment Board /s/ Kathryn Daniels 03/06/2025 CPP Investment Board Private Holdings (4) Inc. /s/ Pierre Abinakle 03/06/2025