Abstract. In Germany, 7.5 Million individuals between 18 and 64 years are considered to be functionally illiterate (Grotlüschen & Riekmann, 2012). Functional illiterates have only rudimentary literacy skills despite attending school for several years. Although they can use written language to a very limited extent, only few functional illiterates attend literacy courses for adults. In addition, most adult literacy courses primarily aim at promoting basic reading and writing skills. Offers specific to workplace literacy are scarce. This review gives an overview of the definition of functional illiteracy. Afterwards, a specific literacy program (AlphaPlus) and its effectiveness will be presented. The reviewed studies indicate that learning to read in adulthood is associated with structural and functional brain changes.