During the 1971-72 school year, data was gathered on pre and post test scores for reading and mathematics achievement from 2 groups of mobile migrant children receiving supplementary educational services. The program, a part of the California Plan for the Education of Migrant Children (Title I, Elementary and Secondary Education Act), used 2 different approaches to provide these services to the second through eighth grade students. Group 1 used the team teaching approach, with trained tutors under the direction of the classroom teacher. A resource teacher gave support and continued inservice training to both the teacher and the tutor. Children in group 2 received services from the several school districts where they were enrolled. The districts provided "pull out" programs in"language development", remedial reading, and English as a second language and were reimbursed for the costs of the services rendered. The cost per child in each program was comparable, but test results showed an important difference in gain scores. Group 1 children met the program objective of at least 1 month of gain on a standardized test for each month in the program, while group 2 did not. Since per pupil costs were the same, it was concluded that the team teaching approach was several times as cost effective as the reimbursement approach. (KM)