Purpose: The purpose of this study is to summarize the ICF foci, looking beyond body structures and function, and to analyze who has been assessed in research about adolescents and young adults (AYAs) with CP in the phase of transition to adulthood. Method: Medline, EMBASE, PsycINFO, and CINAHL databases were searched using terms related to cerebral palsy, adolescents/young adults, health development, participation, and independence. Studies including youth with CP (13–30 years old) published in English from 2014 to 2021 were considered. The methods of assessment reported in the included studies were used to identify the ICF foci and who was assessed. Results: In this study, 86 studies were reviewed. The main ICF foci are activity and participation (51% of the studies), personal factors (23%), ICF not covered (14%), ICF not defined (9%), with environmental factors being the least focused ICF component (3%). Most studies assessed AYAs directly (49% of studies). Conclusions: Activity- and participation-related constructs are the leading research focus of studies, and more attention is needed concerning environmental factors. AYAs are the main source of information, and the perspectives of other key figures are also being valued. To bridge the gap between child and adult health care, a broader view of health development and approaches to explore AYA developmental issues must be taken.