This paper illustrates the development and the experimental validation of a life model for light emitting diodes (LEDs) able to predict the time to failure under different stress conditions associated with the value and time dependence of applied forward current. In the paper, three different life models are derived by exploiting the results of tests under constant forward current. Then, experiments performed by subjecting LEDs to simple load cycles characterized by step-varying forward current are carried out, and the results are employed as a benchmark for the predictions provided by the combined use of the life models derived under constant stress and cumulative damage theory. Index Terms-Life models, light emitting diodes, mean time to failure, accelerated life tests, forward current, Miner's Law.NOTATION S Generic stress Parameters of the IPM model Parameters of the EM model Mean value of LF Fraction of life lost K Number of cycles-to-failure Forward current ACRONYM LED Light Emitting Diodes BITE Built In Test Equipment MTTF Mean Time To Failure ALT Accelerated Life Test IPM Inverse Power Model EM Exponential Model VEC Voltage Endurance Coefficient