Factora intluenriny the detcnnmatiun wl u ~uhLraHe resilient modulus, v alue were mvlu.Ued. Nine te>t ,ites with cohe~ive ,ub_rade soils werc ,elected in the >tate of ! vomin-,. and laboramn testing was conducted on subgrade corea obtained in 1992 and 1993. Several fundamental soil properties of these cores were determined and deflection data from these nine sites were used to determine resilient modulus values with three back calculation programs. The data analysis resulted in several important conclusions about factors that influence the selection of a design subgrade resilient modulus value.