A description of a micro-costing analysis conducted by the Psychiatric Occupational Therapy Department at Rush-Presbyterian St. Luke’s Medical Center is reported. Analysis enabled a department manager to establish cost estimates for the services provided by the department. Included are data reflective of both costs and overhead. The analysis generates information concerning the relative amount of labor used, projected annual volumes, costs for direct and indirect labor, overtime, direct and indirect supplies, allocated cost, and cost for each identified evaluation and/or treatment. Access to cost information enables the department manager to realistically establish charges and to assess efficient use of personnel and supplies. The micro-costing analysis provides a vehicle to communicate departmental needs to the hospital administration based upon documented use of resources, and justified by a thorough cost breakdown.