States currently are in the process of developing child and family outcome measurement systems for young children with disabilities to meet federal data reporting requirements for the Part C (Infants and Toddlers with Disabilities) and Part B Preschool Grants program supported through the Individuals with Disabilities Education Act. This article reviews issues related to the use of assessments in providing outcome data, discusses challenges raised in conducting valid assessments with young children for accountability purposes, and outlines decisions states must make related to assessment as they design and implement outcome measurement approaches. Considerations related to the standardized or curriculum-based measures are discussed along with other choices related to the use of assessment for accountability.