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                                                                      EXHIBIT 12
                            IDX SYSTEMS CORPORATION
                     SCHEDULES OF NET INCOME PER SHARE AND
                         PRO FORMA NET INCOME PER SHARE
                   (IN THOUSANDS, EXCEPT FOR PER SHARE DATA)

                                       

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<CAPTION>
                                                     PRIMARY                 FULLY DILUTED  
                                                 NINE MONTHS ENDED         NINE MONTHS ENDED
                                                   SEPTEMBER 30,             SEPTEMBER 30,
                                               1996        1995            1996        1995
                                             --------     ------          --------    ------- 
<S>                                          <C>       <C>               <C>       <C>
                                                                      
Weighted average shares                        20,661         14,170       20,661      14,170
  outstanding                                                                         
                                                                                      
Net dilutive effect of stock options-                                                 
  based on the treasury stock method                                                  
  using the IPO price until the effective                                             
  date and average price thereafter for                                               
  primary and ending price, if higher,                                                
  for fully diluted                               726          1,289          726       1,289
                                                                                      
Effect of final S corporation                                                         
  distribution                                                 1,789                    1,789     
                                                                                      
Effect of common and common                                                           
  stock equivalent shares issued by                                                   
  the Company during the twelve                                                       
  month period immediately                                                            
  preceding the Company's initial                                                     
  public offering in November 1995,                                                   
  as if they were outstanding for all                                                 
  periods presented prior to the initial                                              
  public offering, using the treasury                                                 
  stock method, as described above                               192                      192
                                               ------        -------     -------      ------- 
                                                                      
Total shares                                   21,387         17,440       21,387      17,440
                                              =======        =======     ========     ======= 
                                                                      
Net income                                    $10,638                     $10,638
                                              =======                    ========
                                                                      
Net income per share                          $  0.50                       $0.50
                                              =======                    ========
                                                                      
Pro forma net income                                         $ 6,899                   $ 6,899
                                                             =======                  ========
                                                                                              
Pro forma net income per share                               $  0.40                     $0.40
                                                             =======                  ======== 
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