Thank you for your question on CMS871v4, Hospital Harm – Severe Hyperglycemia. As this measure is a ratio measure, the measure’s Numerator is pulled directly from the measure’s Initial Population. This is different from proportion measures, where the measure’s Numerator is drawn from and is a subset of the measure’s Denominator. To ensure that the measure calculation appropriately excludes encounters that meet the measure’s exclusion criteria, both Denominator Exclusions and Numerator Exclusions are required. In this measure, because (1) the Denominator and Numerator are both drawn from the same Initial Population and (2) the Denominator Exclusions criteria are the same as the Numerator Exclusions criteria, an encounter that meets the measure’s Denominator Exclusions criteria will also meet the measure’s Numerator Exclusions criteria. Please refer to the CMS Measure Management Systems (MMS) Hub Measure Calculation document ( https://mmshub.cms.gov/sites/default/files/Measure-Calculations.pdf ) for more information on ratio measures.