The ⁵⁸Ni(n,p)⁵⁸Co reaction is a very attractive choice for use as a neutron fluence monitor foil in reactor irradiations. The most important drawback to this reaction is the interference from the 9.15-h half-life ^58mCo metastable state. A methodology is presented in this paper to allow the ^58gCo ground-state activity to be read at short decay times and to be converted into the total ^58tCo activity with no significant increase in the measurement uncertainty. This methodology involves modeling the ^58mCo/^58tCo population ratio. Both theoretical and experimental estimates of the energy dependence of this ratio are presented. A method is presented to accurately measure this ratio. An empirical model of the energy dependence of this ratio is presented to allow simple estimates of the ratio to be made prior to a measurement.