The safe, reliable, and efficient operation and maintenance of rotorcraft drive systems is an essential capability of Army Aviation. From a safety and reliability standpoint, this capability ensures that the rotorcraft performs as expected with minimal risk of unforeseen failure and subsequent downtime. From an efficiency standpoint, this capability ensures that failure risks are identified in a timely manner and require minimal resources to mitigate. The development and integration of new prognostic technologies to provide such capabilities is the goal of current S&T initiatives to transition from CBM to enhanced CBM with extended Maintenance Free Operating Periods (MFOP) and finally, to the Zero Maintenance (ZM) vision. The focus of this paper is reporting progress of a gear health algorithm solution for drive system design and operations.