To examine yearly trends of patent ductus arteriosus (PDA) diagnosis and treatment in very low birth weight infants. In this retrospective cohort study of very low birth weight infants (<1500 g) between 2008 and 2014 across 134 California hospitals, we evaluated PDA diagnosis and treatment by year of birth. Infants were either inborn or transferred in within 2 days after delivery and had no congenital abnormalities. Intervention levels for treatment administered to achieve ductal closure were categorized as none, pharmacologic (indomethacin or ibuprofen), both pharmacologic intervention and surgical ligation, or ligation only. Multivariable logistic regression was used to assess risk factors for PDA diagnosis and treatment. PDA was diagnosed in 42.8% (12 002/28 025) of infants, with a decrease in incidence from 49.2% of 4205 infants born in 2008 to 38.5% of 4001 infants born in 2014. Pharmacologic and/or surgical treatment was given to 30.5% of patients. Between 2008 and 2014, the annual rate of infants who received pharmacologic intervention (30.5% vs 15.7%) or both pharmacologic intervention and surgical ligation (6.9% vs 2.9%) decreased whereas infants who were not treated (60.5% vs 78.3%) or received primary ligation (2.2% vs 3.0%) increased. There is an increasing trend toward not treating patients diagnosed with PDA compared with more intensive treatments: pharmacologic intervention or both pharmacologic intervention and surgical ligation. Possible directions for future study include the impact of these trends on hospital-based and long-term outcomes.