Using data collected by the National Assessment of Educational Progress (NAEP) through its literacy assessment of young adults, this study addressed the question of whether adult patterns of reading activity related to demonstrated proficiencies. Five reading patterns were developed that represent various combinations of high and low activity with newspapers, magazines, books, and brief documents. Interviews were conducted with 3,618 representative young adults from the NAEP sample. These patterns were found to be related to performance on the three NAEP literacy scales--prose, document, and quantitative--for the total population and for major subgroups as well. Through regression analyses, these patterns were shown to have importance in explaining the literacy performance levels of America's 21- to 25-year olds. These findings are discussed in the context of recent cognitive research that emphasizes the importance of graded contextual practice in the transition from novice to expert status. (Contains 5 tables and 40 references.) (Author/SLD)