Thank you for your question about CMS1028v3, Severe Obstetric Complications (SOC). While Numerator 2 is a subset of Numerator 1, there may be blood transfusions in the Numerator 2 population. Numerator 2 includes delivery encounters with SOCs except when blood transfusion is the only SOC. With that said, if a patient goes into cardiac arrest during a procedure or surgery and has a blood transfusion during the delivery encounter, their case could still be in the numerator because the blood transfusion was not the only SOC. Also consider that if a patient has a blood transfusion and a hysterectomy during their delivery encounter without a diagnosis of placenta percreta or placenta increta, their case will qualify for Numerator 2 because hysterectomy is an additional SOC. If that patient has a blood transfusion and a hysterectomy with a diagnosis of placenta percreta, the case will satisfy the numerator exclusion and be removed from the measure. However, if the patient has a blood transfusion and a hysterectomy with a diagnosis of placenta percreta, plus a diagnosis of acute renal failure during the delivery encounter, then the patient stays in Numerator 2 since acute renal failure is an additional SOC. We hope that helps.