This study examined the reading skills of children who have deficient decoding skills in the years following the first grade and traced their progress across 20 sessions of a decoding skills intervention called Word Building. Initially, the children demonstrated deficits in decoding, reading comprehension, and phonemic awareness skills. Further examination of decoding attempts revealed a pattern of accurate decoding of the first grapheme in a word, followed by relatively worse performance on subsequent vowels and consonants, suggesting that these children were not engaging in full alphabetic decoding. The intervention directed attention to each grapheme position within a word through a procedure of progressive minimal pairing of words that differed by one grapheme. Relative to children randomly assigned to a control group, children assigned to the intervention condition demonstrated significantly greater improvements in decoding attempts at all grapheme positions and also demonstrated significantly greater improvements in standardized measures of decoding, reading comprehension, and phonological awareness. Results are discussed in terms of the consequences of not fully engaging in alphabetic decoding during early reading experience, and the self-teaching role of alphabetic decoding for improving word identification, reading comprehension, and phonological awareness skills.