Pediatric genetic testing primarily focuses on medical management in childhood, justified by protecting children’s current interests and future autonomy. While professional societies encourage including adolescents in these decisions, little is known about the factors influencing adolescents’ choices and the best methods to promote their confidence and reduce regret in genetic testing decisions. We conducted a clinical trial in which adolescents decide over a series of timepoints which personal genetic testing results to learn among treatable, preventable, and adult-onset conditions and carrier traits. To understand participants’ decision-making confidence and stability, we purposively sampled assenting and consenting adolescents who decided to learn all (7), some (7), or no (8) personal genetic test results to participate in a qualitative interview. Participants expressed high decision stability and confidence in their choices, which was increased by involving a parent in decision-making and having time to revisit their choices. Our findings suggest consenting adolescents may benefit from involving a parent in the decision-making process, and that genetic professionals should consider offering assenting and consenting adolescents opportunities to revisit and revise decisions about learning personal genetic information. Although honoring adolescents’ desire for informed decision-making as a process rather than a singular event may be feasible in research contexts, this proposed model contradicts clinical practice norms in which patients cannot change their minds about whether and which genetic test results will be returned once clinical genetic analysis commences. These findings illustrate the potential complexities of translating approaches used to promote adolescent-engaged decision-making in genomic research to precision medicine.