Most individuals with autism spectrum disorder (ASD) -a complex, life-long developmental disorder-do not have access to the care required to address their diverse health needs . Here, we review: (1) common barriers to healthcare access (shortage/cost of services; physician awareness; stigma); (2) barriers encountered primarily during childhood (limited screening/diagnosis; unclear referral pathways), transition to adulthood (insufficient healthcare transition services; suboptimal physician awareness of healthcare needs) and adulthood (shortage of services/limited insurance; communication difficulties with physicians; limited awareness of healthcare needs of aging adults); and (3) advances in research/program development for better healthcare access . A robust understanding of barriers to accessing healthcare across the lifespan of autistic individuals is critical to ensuring the best use of healthcare resources to improve social, physical, and mental health outcomes . Stakeholders must strengthen healthcare service provision by coming together to: better understand healthcare needs of underserved populations; strengthen medical training on care of autistic individuals; increase public awareness of ASD; promote research into/uptake of tools for ASD screening, diagnosis, and treatment; understand specific healthcare needs of autistic individuals in lower resource countries; and conduct longitudinal studies to understand the lifetime health, social, and economic impacts of ASD and enable the evaluation of novel approaches to increasing healthcare access . IMPACT: Despite the growing body of evidence, our understanding of barriers to healthcare encountered by individuals with ASD remains limited, particularly beyond childhood and in lower resource countries . We describe current and emerging barriers to healthcare access encountered by individuals with ASD across the lifespan . We recommend that stakeholders develop evidence-informed policies, programs, and technologies that address barriers to healthcare access for individuals with ASD and consider broad, equitable implementation to maximize impact.