To assess the rate of spontaneous closure and the incidence of adverse events in infants discharged home with a patent ductus arteriosus. In a prospective multicenter study, we enrolled 201 premature infants (gestational age of 23-32weeks at birth) discharged home with a persistently patent ductus arteriosus (PDA) and followed their PDA status at 6-month intervals through 18months of age. The primary study outcome was the rate and timing of spontaneous ductal closure. Secondary outcomes included rate of assisted closure and the incidence of serious adverse events. Spontaneous ductal closure occurred in 95 infants (47%) at 12months and 117 infants (58%) by 18months. Seventeen infants (8.4%) received assisted closure with surgical ligation or device assisted occlusion. Three infants died (1.5%). Although infants with spontaneous closure had a higher mean birth weight and gestational age compared with infants with a persistent PDA or assisted closure, we did not identify other factors predictive of spontaneous closure. Spontaneous closure of the PDA occurred in slightly less than one-half of premature infants discharged with a patent ductus by 1year, lower than prior published reports. The high rate of assisted closure and/or adverse events in this population warrants close surveillance following discharge. ClinicalTrials.gov: NCT02750228.