The purpose of this paper is to describe briefly the development and utility of the "Assessment of Reading Instructional Knowledge-Adults" ("ARIK-A"), the only nationally normed (n?=?468) measure of adult reading instructional knowledge, created to facilitate professional development of adult educators. Developmental data reveal reliabilities ranging from 0.73 to 0.85 for five "ARIK-A" scales (alphabetics, fluency, vocabulary, comprehension, and assessment) and 0.91 for the composite score; factor analytic data and expert review provide support for construct validity as well. Information on how to use the "ARIK-A" to determine mastery and relative standing is presented. With two alternate forms, the "ARIK-A" is a promising and needed tool for adult education practitioners within continuing education and professional development contexts.