Accelerated testing is increasingly important to assure product reliability with reduced development time. Reliability predictions are sensitive to the accelerated life model selected. This presentation discusses principles for model selection. Using the fact that the Eyring, Arrhenius and Inverse Power Law models are nested special cases of a more general model, this session will present a statistical test, using existing ReliaSoft software for model selection among them. Simulation results will illustrate the power of the test, and we will discuss an example.