Abstract: BACKGROUND: Hyperbilirubinemia (HB), defined as elevated total serum bilirubin (TSB) levels, commonly affects neonates and requires prompt treatment to prevent neurological complications. Up to 10%of neonates experience rebound hyperbilirubinemia (RHB), requiring re-initiation of treatment. Unfortunately, treatment guidelines lack practical recommendations surrounding subthreshold phototherapy, treatment termination, and RHB investigations. We examined local management practices for HB and RHB treatment in a well newborn nursery. As a secondary aim, we investigated the association between treatment practices and RHB rates. METHODS: Retrospective chart review identified neonates treated for hyperbilirubinemia between January 2015 and December 2019 during their birth hospitalization at a tertiary care centre. Standardized data collection sheets were used to record treatment parameters. RESULTS: Over the 5-year period, there were 9683 births and 305 (3.15%) neonates received phototherapy. Of the treated cases, 20–25%were subthreshold to practice guideline values. Upon treatment termination 25–55%of cases had TSB levels within 3 mg/dL, which may increase the risk of RHB. In our cohort, 20.3%of treated cases experienced one episode of RHB and 3.9%experienced two episodes of RHB. Although clinicians evaluated neonates for RHB 0–12 hours following treatment termination prior to discharge, many cases were identified in outpatient settings and required re-admission for phototherapy. CONCLUSION: When managing HB and RHB, treatment practices such as when to terminate treatment in relation to threshold values, and timing of RHB investigations, are largely inconsistent amongst clinicians. Future studies are required to better understand the landscape of hyperbilirubinemia treatment beyond initiation of phototherapy.