Data were obtained by telephonically contacting every State correctional department in April 1994. Informed contacts in each department were asked the same questions in order to promote a consistent interviewing format. Thirty States reported having to house their prisoners in county jails in order to alleviate overcrowding in the State prison system. Of the 30 States, 12 have contractual arrangements with all or some of their counties. Seven States have statewide statutes which stipulate under what circumstances and to what extent the State may house their prisoners in county jails. Two States have court orders only, which limit the time and/or number of prisoners held at the county level, seven States have some combination of the above, and two States have some other informal arrangement. In four States, counties have arrangements with the State to house county inmates in State prisons because of massive overcrowding at the local level. Five States have State only correctional systems where there are no county jails; 31 States reimburse counties for the expenses incurred in holding State prisoners but not necessarily for purposes of overcrowding relief. Of the 31 States, 17 pay a set per diem to reimburse counties that hold State prisoners. Fourteen States have varying reimbursement rates, depending on the costs of county facilities and the circumstances in which a prisoner is held at the local level. Reimbursement rates vary from $1.75 per day in Alabama to $71 per day in Kansas. Additionally, at least 10 States also reimburse for some or all of the extra costs associated with health care and similar inmate services. In three States, counties are not reimbursed for housing State prisoners. A state-by-state analysis of State prisoners in county jails is appended. References, figures, and tables