Thank you for your inquiry regarding CMS0996v5, Appropriate Treatment for ST-Segment Elevation Myocardial Infarction (STEMI) Patients in the Emergency Department (ED) measure. We understand the intent of your inquiry is to recommend additional exclusions to the measure numerator to account for cases where a patient’s initial electrocardiogram (EKG) is negative, but a subsequent EKG shows STEMI findings. We can confirm the measure uses the diagnoses of STEMI during the ED encounter as the “start time for the intervention,” and does not use EKG timing or frequency. This decision was based on clinical expert input and measure testing results indicating that EKG timing in electronic health record (EHR) documentation was unreliable. However, the issue of the measure not excluding cases where the STEMI develops during the ED encounter, but the measure still assesses appropriate treatment starting from ED arrival time has previously been brought to the attention of CMS and the measure developer. The measure developer will continue to evaluate feedback and recommendations during the annual update cycle and will work with CMS to update the measure as needed to align with clinical guidelines and workflow.