The problems stated for this investigation were: (1) to determine the order of introduction of the common phoneme-grapheme correspondences needed for use in decoding of written words introduced in the elementary grades, and (2) to ascertain at what specific readability level a particular graphemic option occurred most frequently. A master word list was developed for readability levels 1.0-5.0 by extracting words from each of the following word lists: A Revised Core Vocabulary; A Basic Vocabulary for Grades 1-8, An Advanced Vocabulary for Grades 9-13; Basic Elementary Reading Vocabularies; Word Frequency Book; and Computational Analysis for Present-Day American English. For every level, 1.0-5.0, each phoneme was classified according to its corresponding graphemic option. These classifications were analyzed as to the readability levels at which they occurred in the most frequently used words. This analysis provided a listing of phoneme-grapheme correspondences which appeared most frequently in words at each level. The findings suggested that a hierarchy for teaching phoneme-grapheme correspondences does exist and should be used for developing a scope and sequence for teaching these correspondences at readability levels 1.0-5.0. (Author/WR)