Drawing on data from a study of Title I of the Elementary and Secondary Education Act (ESEA), this report focuses on Title I's supplement-not-supplant and excess costs provisions and their effects on program design. Following discussions of the legal framework of Title I and Chapter 1 of the Education Consolidation and Improvement Act (ECIA), the report's central section details findings concerning current program design practices (pullout vs. inclass), school district rationales for program design choices, and the relationship of Title I programs to regular classroom instruction. The next section, "Continuing Misconceptions about the Supplement-Not-Supplant Provision," is followed by a summary and outline of implications, a selected bibliography, and appendixed providing (1)"Title I Excess Costs Models Applying the Supplement-Not-Supplant Concept to Program Design," (2) an excerpt from a United States Department of Education Title I evaluation report to Congress, (3) an excerpt from a school district's 1981 policy memorandum discussing alternatives to the pullout approach, and (4) a 1981 school district memorandum excerpt explaining the district's elementary level excess costs for reading and math programs. The report concludes by encouraging further examination of the implementation of the requirement that federally funded compensatory education provide supplemental rather than substitute services. (JBM)