This study examined similarities and differences in measurement properties and score comparability of the "Supports Intensity Scale-Adult Version" (16-64 years) and the "Supports Intensity Scale-Children's Version" (5-16 years). Data were collected from 142 adolescents with intellectual disability with both versions of the "Supports Intensity Scale". Data analyses indicated clear alignment of the specific set of items across parallel activity domains, as well as support for score comparability across two assessments. This suggests the two versions of "Supports Intensity Scale" can be used with confidence with transition-aged students to assess their support needs and inform supports planning, depending on the purpose of assessment. Implications and future directions for research and practice are discussed. [This article was published in "Career Development and Transition for Exceptional Individuals" (EJ1116494).]