Thank you for your question about CMS1028v3 Severe Obstetric Complications.   The first few lines of logic for Numerator Exclusion 1 (SOC with Hysterectomy or Blood Transfusion with Placenta Increta or Placenta Percreta Without Additional SOC) evaluates Numerator 1 for cases that have a diagnosis of placenta increta or placenta percreta with a blood transfusion or hysterectomy during the delivery encounter. If yes, the case only qualifies for the numerator exclusion if there are no "Additional SOC" which the second half of the definition addresses (by saying except…): SMM diagnosis which must not be present on admission or unable to determine, SMM procedure other than blood transfusion or hysterectomy (meaning a cardiac conversion, tracheostomy, or ventilation procedure), or Delivery encounter with expiration.   The "SDE SOC Diagnoses Detail" logic identifies which diagnoses put the case in the numerator, uses the function "SOCDxCategory(Dx Code)" to identify which diagnosis code(s) from which value set(s) were present for each patient. "Complication C" and "procedure P" are variables in the logic to identify when complications or procedures are present in the numerator, and to return the specific condition/diagnosis codes and procedure codes. As supplemental data elements, implementers do not need to do anything with it. The receiving system will compute it.