This chapter seeks to provide the field of education for adult English speakers of other languages--at local, state, and national levels--with a timely overview of the state of assessment in adult English for Speakers of Other Languages (ESOL) programs in the United States. It also seeks to provide a brief description of assessment reform initiatives in K-12 education and in adult language education abroad that might serve as models for adult education in the United States. The authors' intent is to help program staff and state and national policymakers make informed choices about assessment measures and procedures and to foster a collaborative effort to build an accountability system that addresses the needs of each stakeholder in a more effective adult education instructional system. For the purposes of this report, the authors use the term assessment in a broad sense: to find out what learners want, know, and can do at the beginning of instruction (needs, placement, and diagnosis), throughout instruction (ongoing progress), and at the end of instruction (achievement and outcomes). The information presented is based on a literature review from the fields of language assessment and government policy, reviews of standardized tests currently being used in adult ESOL programs, and discussions with experienced adult ESOL educators. The authors explore three key issues and make recommendations based on the findings: (1) What implications do legislative requirements for performance measures have for adult ESOL programs? (2) What assessment tools and processes are available and how adequately do they meet the needs of all stakeholders? and (3) What insights can be gained from the assessment reform experience of K-12 education and adult language education abroad? Ordering Information for Selected Standardized Tests is appended. [Chapter 6 in: Annual Review of Adult Learning and Literacy. Volume 1; copublished by Jossey-Bass, Inc.; see ED436673.]