In order to understand the degradation mechanisms and failure precursors of metallized thin film capacitors (MTFC) used in photovoltaic (PV) inverters, we have carried out accelerated testing on MTFCs. By understanding the degradation mechanisms and precursors of imminent catastrophic failure, implementation of a prognostics and health management (PHM) plan can be used to optimize PV array operations and maintenance (O&M), decreasing cost per watt towards the US Department of Energy goals.