Parents of infants hospitalized in a neonatal intensive care unit (NICU) experience increased anxiety and stress, which may persist after discharge. The rationale and design of a randomized clinical trial assessing the impact of a 1-year, post-discharge, peer support intervention (parent navigation) on parental mental health and infant health care utilization is described. Qualitative methods guided the adaptation of an existing parent support program to target emotional and resource-related needs of NICU families. Approximately 300 parent-infant dyads were enrolled at discharge and randomized to either receive a care notebook (control group) or a parent navigator and a care notebook (intervention group). We aim to determine if the parent navigator intervention: 1) increases self-efficacy and decreases stress in parents, 2) decreases overall levels of anxiety and depression in parents, 3) decreases infant hospitalizations and emergency department visits, and 4) increases adherence to infant vaccination recommendations during 1year of follow-up. Standardized, self-reported psychological scales to assess parent depression, anxiety, self-efficacy and social support were administered at baseline (NICU discharge) and at 1-week, 1-, 3-, 6- and 12-month intervals. Infant immunization status and health care utilization during the study period were also assessed. This paper reviews challenges and successes during implementation. If this intervention improves outcomes, NICUs may choose to provide similar parent navigation services for infants and families transitioning from the NICU to home. This study was registered with ClinicalTrials.gov (NCT02643472) on December 31, 2015.