This is a randomized, prospective, single-center, pilot study assessing once daily Envarsus XR® medication efficacy, adverse events, medication non-adherence, patient-reported outcomes, and abbreviated pharmacokinetics/ dose finding to evaluate a population of adolescent renal transplant recipients while on stable tacrolimus (twice daily) and then after conversion to Envarsus XR® to provide critical efficacy, safety, dose-finding, adherence, and patient reported outcome data that could lead to adoption of Envarsus XR® as a mainstay of pediatric/adolescent post-transplant immunosuppression.