This white paper assesses the temperature and humidity acceleration factors both with and without DC bias. The influence of these factors on MLV lifetime will be addressed, especially as it relates to the operating environment seen by MLVs. Additionally, technical explanations of the different failure modes and failure mechanisms are provided, specifically with regards to temperature and humidity exposure. Over 50 years ago, typical life tests simulated the operational conditions of a product. However, these tests became useless due to the rapid improvement of electronic component reliability. The solution was to develop a testing methodology utilizing the same types of stress, but at higher levels than typical operating conditions. The purpose of these accelerated tests was to shorten the timeframe necessary to obtain relevant results through an aging deterioration of the device in order to induce normal failures.