Lifelong learning has become an important goal of education over the last decade. According to the United States Department of Education (2001), nearly 3 million students over age 17 (excluding those institutionalized) enrolled in adult basic education, adult secondary education, or English as a second language classes in the United States. Historically, language assessment of this special population, often immigrants or low-income participants, at best, has been acceptable, at worst, inadequate. In the early 1980's, the California Adult Student Assessment System (CASAS, renamed the Comprehensive Adult Student Assessment System) was developed to create curriculum and testing materials to assess this unique group of students. CASAS tests are used throughout the United States to evaluate adult basic skills in a wide variety of workforce and academic programs. This review focuses on the most widely used CASAS exams: the multilevel criterion-referenced life skills tests that assess basic literacy and reading ability.