This document contains an interim report on the Head Start/Medicaid Early and Periodic Screening, Diagnosis, and Treatment (EPSDT) Collaborative Effort, a demonstration program that was initiated by the Office of Child Development in 1974. The report is primarily a presentation of the data collected from February 1975 to June 30, 1975, concerning six aspects of the Head Start/EPSDT Collaborative Effort during its first year: (1) Medicaid status of children participating in EPSDT, (2) previous health care status of participating children, (3) organization and operation of EPSDT components in the selected Head Start projects, (4) interactions between Head Start selected projects and the state and local agencies responsible for the provision and administration of EPSDT services in the target states, (5) characteristics of the state EPSDT plans and their operations in the target states, and (6) technical support provided and additional need for technical assistance. Information pertaining to medical services and service evaluation is not included. A tentative statement of findings on each of these aspects has been included, but the primary emphasis in this interim report is on the presentation of data in tabular form. (Author/JMB)