The number of people with autism and intellectual disability has shown a dramatic increase in prevalence in the past 20 years. Once viewed as the province of pediatric trained mental health specialists, practitioners are increasingly asked to manage the growing number of patients with these mental disorders and their comorbidities as they age beyond adolescence to older age and often feel poorly prepared to do so. This session will describe key developmental lines and ways to help patients and their families with the complex mental health challenges throughout the lifespan.