This brief is one in a series exploring the pilot measure, known as the Healthy and Ready to Learn (HRTL) National Outcome Measure (NOM). National Outcome Measures (NOMs) cross all population domains and reflect maternal and child population health status. More than two dozen NOMs have been developed and are tracked and reported by the Health Resources and Services Administration’s Maternal and Child Health Bureau (HRSA MCHB) at the national and state levels. This particular brief reviews the current status of and evidence for the HRTL measure developed as a proposed National Outcome Measure (NOM) for the federal Title V Maternal and Child Health Services Block Grant, and compares it with other well-being and readiness measures. Its purpose is to aid researchers, policymakers, and early childhood advocates in understanding the utility of the new HRTL measure, by itself and in conjunction with other measures of kindergarten readiness. The brief also aims to facilitate appropriate interpretation of future findings from the HRTL measure and recommends next steps in the development of the measure. (author abstract)