 Children, adolescents, and young adults are encouraged to see their primary care provider on a regular basis as they grow and develop. But how often is regular? Babies should have checkups between birth and one month and then at 2, 4, 6, 9, 12, and 18 months. Toddlers should have checkups at 24 and 30 months. And starting at age 3, children and adolescents should have checkups every year.