For the Illinois Department of Commerce & Economic Opportunity, we performed pre-approval review of all custom/standard projects for which the expected incentive exceeded $30,000. For instance, during 2015-2016, we performed more than 200 such reviews of custom/standard projects. For these reviews, we determined whether or not available project documentation allowed for determining measure baselines and provided sufficient information with which the appropriateness of the proposed method for calculating energy impacts could be determined. If additional data were required, we requested and obtained additional data from program participants and partners assisting project implementation. If we identified an error in the proposed savings analysis method, it proposed an alternative savings analysis methodology. Our pre-approval reviews characterized the nature and impact of error associated with the ex ante energy savings estimations. Accounting for available data, our pre-approval reviews also characterized the level of uncertainty associated with ex ante savings estimates. Department program staff members then used the pre-approval review findings to inform their decision-making regarding the disposition of the projects.