We explored health care differences across the lifespan comparing people with developmental disabilities to people without developmental disabilities. Health care disparities are inequities occurring during the provision of and in access to health care that are experienced by socially disadvantaged populations. We discovered significant disparities between persons with and without developmental disabilities in health status, quality, utilization, access, and unmet health care needs. Our results highlight the need to educate health care clinicians on the care of patients with developmental disabilities of all ages.