The Woodcock-Johnson IV Tests of Achievement (WJ IV ACH; Schrank, Mather, & McGrew, 2014a) is an individually administered measure containing tests of reading, mathematics, written language, and academic knowledge. Areas of reading, mathematics, and written language each include tests of basic skills, fluency, and application. Academic knowledge includes tests of science, social studies, and humanities. The test authors note that the WJ IV ACH can be used to assist with determining an individual's academic strengths and weaknesses, diagnosing specific abilities and disabilities, and educational planning (Schrank et al., 2014a). When used in conjunction with the WJ IV Tests of Cognitive Abilities (WJ IV COG; Schrank, McGrew, & Mather, 2014) and the WJ IV Tests of Oral Language (WJ IV OL; Schrank, Mather, & McGrew, 2014b), it can also be used to evaluate variations between an individual's achievement and cognitive and linguistic abilities. Interpretation of WJ IV test batteries is based on the Cattell-Horn-Carroll (CHC) theory of cognitive abilities (see Schneider & McGrew, 2012). The WJ IV ACH was published by Riverside in 2014; the previous version, the WJ III Tests of Achievement (Woodcock, McGrew, & Mather, 2001), was published in 2001. There are seven new tests in the WJ IV ACH; however, it no longer includes tests of oral language abilities as these are now published separately. Examiners should have knowledge of exact WJ IV ACH administration and scoring procedures; graduate-level training in educational and psychological assessment is recommended (Schrank et al., 2014a). The test may be administered to individuals from age 2 to over 90 years. Most of the tests in the WJ IV ACH require 5 to 10 min to administer; however, some require 15 to 20 min. This review concluded that despite some relatively minor limitations, the WJ IV ACH is a strong test and meets its stated purpose. If used appropriately, and as a complement to other forms of psychological and educational data, it can certainly assist with diagnosis of specific disabilities and can serve as a general evaluation tool to guide more narrow evaluations that can better inform intervention and educational planning.