Maintenance on gas turbine engines results from failures in one or more of the engine's major subsections. Maintenance and support costs can be reduced if the capability exists to isolate the failures down to the lowest possible component in the engine. The modular engine maintenance concept has recently been evolved to facilitate this cost reduction. The important considerations as well as the benefits of this concept are discussed. Considerations included are: 1) design, 2) failure modes and isolation techniques, and 3) implementation. The Air Force F100-PW-100 engine maintenance concept is used for discussion purposes.