The age at which a child should transition from a pediatrician to a family doctor or general practitioner can vary depending on individual circumstances and the preferences of the family. In general, the transition typically occurs between the ages of 18 and 21 years old, when a person becomes an adult and is no longer considered as part of the pediatric age group. Some factors to consider when making this transition include the overall health and medical needs of the individual, as well as any specific healthcare concerns they may have. Additionally, it can be helpful to discuss the transition with the pediatrician and receive their recommendations on when the switch would be appropriate. Ultimately, the decision on when to switch from a pediatrician to a family doctor or general practitioner should be based on the individual's healthcare needs, comfort level, and the availability of appropriate medical care for adult patients in their area.