In Research in Nursing & Health, Jeannette Rogowski and colleagues, including Eileen Lake, provide the first report of national data on nurse-to-patient ratios in the neonatal intensive care unit (NICU) by infant acuity level. Data were collected in two sequential studies in 104 NICUs. The study finds most NICU infants were low-acuity, and that 12% of infants were high-acuity. The average nurse cared for two infants, but the nurse-to-infant ratio ranged from 1 nurse to 3 infants for low acuity, to almost 1-to-1 ratio for the highest acuity. The study found that infant acuity was the sole determinant of nurse workload, which was not affected by nurse education, experience, certification, or availability of other providers. Further research is needed to understand whether these assignment patterns optimize outcomes for critically ill infants.