EXHIBIT 23 CONSENT OF INDEPENDENT CERTIFIED PUBLIC ACCOUNTANTS The Board Of Directors IDX Systems Corporation We consent to incorporation by reference in the registration statement (No. 333-31045) on Form S-8 of IDX Systems Corporation of our report dated May 13, 1999 relating to the statements of net assets available for benefits of PHAMIS Inc. Salary Savings and Deferral Plan as of December 31, 1998 and 1997, and the statements of changes in net assets available for benefits for the years then ended, and the related supplementary schedules as of and for the year ended December 31, 1998, which report appears in the December 31, 1998 annual report on Form 11-K of PHAMIS Inc. Salary Savings and Deferral Plan. /s/ KPMG LLP KPMG LLP Seattle, Washington June 28, 1999 Page 25