This study assessed the efficacy of a time-sensitive cognitive remediation summer program (CRSP) that provided patients and their families with tools to help mitigate neurocognitive deficits and promote independence to foster precursor transition of medical care skills. A total of 38 participants (aged 9–15) were included in one of the CRSPs offered yearly from 2013 to 2016. A longitudinal design was employed and at each evaluation time point, one week before start of the CRSP (pre-testing) and within three weeks after the end of the program (post-testing)), participants were administered measures of executive functioning in addition to parent ratings of behavior, executive functioning, and adaptive skills (Year 1–Year 4). In Year 4, additional measures were collected, including parenting style and parent engagement and involvement in the program. Results from Year 1 to Year 4 (n = 35) demonstrated that participants in the CRSP showed significant improvement on neuropsychological testing in sustained and selective attention, planning, and cognitive flexibility. Robust changes in parent ratings of adaptive functioning from pre- to post-treatment were also found. Specific to Year 4 (n = 13), results revealed that participants showed improvement in levels of independence with at least one of the individualized goals focused on during the program. This study provided a systematic method to gauge the levels of instruction necessary to reach goals, a crucial tool in skill-teaching. Overall, our study provides evidence for the efficacy of the CRSP and validates a feasible intervention that can be integrated into standard of care for pediatric medical populations.