A single subject alternating treatment design was used to compare the relative effectiveness of one-to-one embedded instruction in the general education classroom and one-to-one massed practice instruction in a special education class. Four middle school students with developmental disabilities, their special education teacher, and paraprofessional participated in the study. The results indicate that embedded instruction is an effective instructional strategy for students with developmental disabilities being served in inclusive settings. However, the results indicate that there was some difference in the efficiency of the two instructional formats. Two students reached criterion more rapidly in the one-to-one massed instructional intervention while the one-to-one embedded instruction was more efficient for one student. There was no difference between the interventions for the fourth student. Finally, the study validated previous research that found that both special education teachers and paraprofessionals can, with minimal training, accurately implement embedded instructional interventions in the general education classroom. Implications for practitioners and researchers are discussed.