In your example, the measurement period is 180 days (January 1_June 30). Step 2 of the numerator criteria reads, "within the measurement period, count the number of days the member was covered." In this case, look for covered days from January 1_June 30; in essence, the numerator is being capped. The PDC is not calculated by summing the days supply for pharmacy claims. You may need to set up a time array for each claim, to identify the time frame covered by each fill, then count the number of days in the measurement period that are covered by the time arrays. Thus, the numerator may not exceed the denominator for the person-level PDC calculation. Refer to the attached example for SAS code for arrays.