Thank you for your question regarding CMS871v3, Hospital Harm – Severe Hyperglycemia. For this measure, eligible hospital days are defined as full 24-hour periods that start at the time of admission to the hospital, excluding the last period before discharge from hospital inpatient if it is less than 24 hours. The “Encounter, Performed: Encounter Inpatient” data element used in the measure’s ‘Qualifying Encounter’ logic definition assesses the time of the admission event itself, rather than the admission order. Time in the emergency department and observation is also included as part of the inpatient hospitalization period when the transition between these encounters (if they exist) and the inpatient encounter are within an hour or less of each other. This measure’s Numerator identifies inpatient hospitalizations with a hyperglycemic event within the first 10 days of the encounter minus the first 24 hours, and minus the last period before discharge from the hospital if less than 24 hours. Glucose results from the first 24-hour period after admission to the hospital are not evaluated to account for potentially poor glucose control outside of the hospital setting or that preceded the start of hospital care. As the measure does not count any hyperglycemic events that occur in the first 24 hours, day 1 is then not considered an eligible hospital day for the Measure Observations. Please see the attached table for an illustration of how the measure determines hospital days.