In April 1984, the Department of the Navy designated Everett, Washington as the preferred site of a Carrier Battle Group Homeport. By 1990 the new base will result in an influx of about 13,500 active duty personnel and their dependents, and an additional 6,300 civilians, into Snohomish County. This sudden population increase is expected to have an impact on social and health programs administered through the Washington State Department of Social and Health Services (DSHS). To help plan for the increased demand on services, the DSHS Region 3 Coordinating Council and Advisory Committee sponsored a study of the projected caseload and fiscal impacts of the Navy Homeport. The study included only Snohomish County because 97 percent of the population arriving is expected to live in that county. The methodology developed for the study can be used to revise and update projected impacts as new data become available. The study produced caseload projections for 1990, with and without the Navy Homeport, for 32 services likely to be affected by the Navy base. The fiscal impact was calculated for 14 individual services, and the total fiscal impact of the Homeport Project was estimated. The major findings of this study are: Across all services, the Navy Homeport will account for more than one-third of the projected caseload increase between 1985 and 1990. In 1990, the Navy Homeport will produce an increase of 408 clients in the AFDC-R program, 851 clients in the Food Stamp program, 592 clients in the Medicaid program, and 719 clients in the Support Enforcement program. The cost of extending income assistance and medical assistance programs to the increased population resulting from the Navy Homeport will be about $1.4 million per year in 1990 (1986 dollars). The DSHS grant and non-grant cost associated with the Navy Homeport Project is conservatively estimated at about $2.3 million per year in 1990 (1986 dollars). Because the cost of several smaller DSHS programs likely to be affected by the navy base are excluded, this figure represents approximately 80 percent of the total anticipated fiscal impact on the department.