Publisher Summary This chapter focuses on the maintenance, availability, and life cycle usage of microturbines. Most manufacturers offer service contracts for maintenance. The combustor and associated hot section parts should be inspected periodically. Air and oil filters must be replaced periodically, and oil bearings should be inspected. Microturbines operating in environments with extremely dusty air require more frequent air-filter changes. A microturbine overhaul is needed every 20,000–40,000 hours, depending on manufacturer, fuel type, and operating environment. A typical overhaul consists of replacing the main shell with the compressor and turbine attached, general inspection, and, if necessary, replacing the combustor. During overhaul, other components are examined to determine whether wear has occurred, with replacements made as required. The equipment life of microturbines is estimated to be 10 years; this includes at least one major overhaul in that time frame. Costs of these overhauls are included in the non-fuel related maintenance item estimates for calculating costs per fired hour. The economic life of microturbine systems is typically assumed to be 10 years.