Little is known about Young adults with Autism Spectrum Disorder (YA-ASD) health, healthcare and safety needs. This study describes the validation of a health care transition measure for YA-ASD, the Health-Related Independence (HRI). We collected data from caregivers (n = 490) at five Autism Treatment Network sites and compared the psychometric properties of HRI to the gold standard (STAR[subscript x]) and other validated measures. A Confirmatory Factor Analysis and item culling resulted in 30 items addressing six subscales. Content, criterion, and construct validity and internal consistency indicated high validity and reliability for the scale and subscales. HRI is a validated caregiver-report measure of YA-ASD's self-management, safety, and transition skills. This novel measure will be a useful tool in clinics, intervention development, and research.