Seagate designed a micro-actuator that enables fine positioning by a dual-stage servo system to increase recording density of hard disk drives (HDDs). In this paper, a degradation accelerated life test (ALT) performed at Seagate using two stressors (temperature and AC voltage) is discussed. Statistical ALT analysis techniques were used to assess the test results. Finally, the Palgrem-Miner's damage accumulation rule was employed (applied AC voltage on micro-actuator being a narrow-band random process) to predict the micro-actuator reliability. The results show that the micro-actuator designed by Seagate demonstrates very high long-term reliability. The approach presented in this paper can be universally applied for predicting device field reliability using in-house ALT data modeling and field usage profile information