Projections of future inmate populations were compared with estimates of future prison and correctional institution capacity to identify the potential deficit or surplus in bedspace and estimate costs to reduce crowding through new prison construction or expansion projects (assuming no alternatives to increasing prison capacity are developed). In fiscal 1983 the Federal prison system had an average daily inmate population of 29,718; the projected fiscal 1988 inmate population is 35,182. If no further capacity increases occur, and the Federal inmate population reaches the Bureau of Prison's unofficial fiscal 1990 estimate of 37,977 inmates, the deficit in bedspace will be 10,853, producing a 40 percent overcrowding rate. The rated capacity of the District's institutional facilities was 4,599 in fiscal 1983; average daily inmate population exceeded capacity by 11.4 percent. If no further capacity increases occur and the incarcerated inmate population reaches 5,900, as projected for fiscal 1987, overcrowding rates will remain constant at 10.4 percent through fiscal 1990. In 1983, approximately 391,597 persons were incarcerated in State prisons/correctional institutions, 17.8 percent over rated capacity. Without additional increases in rated capacities, State prisons/correctional institutions will experience a bedspace deficit of 108,321 in 1990, an overcrowding rate of 25.8 percent.