Recent data for the State of Wisconsin indicates that the National Ambient Air Quality Standards for CO and O(x) will not be attained in all areas of the state by 1982, even if all reasonably available control technologies are applied. In view of this, it is likely that the state will request from EPA an extension of the compliance date beyond 1982. In order for this request to be considered, the state must, among other things, have adopted a firm schedule for implementing a motor vehicle inspection and maintenance (I/M) program in the highly urbanized nonattainment areas. In this connection, the State of Wisconsin is currently in the initial states of planning for the implementation of an I/M program. As part of this initial effort, several candidate program configurations have been analyzed from the standpoint of costs, benefits, and other requirements. These analyses, which are reported herein, will provide the basis for the state to select one specific option that will eventually be implemented.