In this paper, we present a methodology for estimating the protection levels of critical equipment against IEMI. We apply the method to a wireless communication infrastructure, but it can be applied to any critical infrastructure. The required protection levels that need to be implemented are determined by analyzing the susceptibility of the victim, and the threat level associated with a specific IEMI scenario. Based on the required protection levels, possible protection strategies are identified and the associated costs are evaluated. The total cost includes the monetary cost and the costs related to loss of performance. The method we present can be used for a quantitative comparison between different protection techniques in terms of monetary cost. The method is applied to develop a strategy for protecting a wireless receiver from damage due to in-band interference using an RF limiter. We also analyze the loss in performance due to the installation of a limiter. It is shown that the noise figure degradation is linearly dependent on the insertion loss of the limiter.