Ninety million adults in the United Stated have low literacy skills according to the National Research Council (2012). Given the number of people directly affected, and the associated costs to public health and employment, there is a serious lack of rigorous research studying interventions for adult struggling readers (Greenberg, 2008; Kruidener, 2002; Tighe & Schatschneider, 2016). Adults seeking alternative high school credentials like the General Education Development (GED) diploma, and those in Adult Basic Education (ABE) programs have a wide range of reading skill deficits (Perin, Flugman & Spiegal, 2006; Greenberg, Ehri & Perin, 1997). Surprisingly, despite promising results of morphological instruction with both children and adults, there is little evidence that adult literacy studies are taking advantage of the potential of teaching morphemes, including prefixes, root words and suffixes (Alamprese,