INTRODUCTION: Accelerated testing, using frequencies higher than clinically observed, has been used to reduce time and cost of fatigue testing. Unfortunately, changes in a device design or manufacturing process may require repeating fatigue testing to show that the change does not adversely affect the specified device lifetime. Objective: To test implantable devices in an accelerated fatigue failure test at frequencies and strains higher than clinically seen. Designs or processes resulting in devices that fail at an unacceptable fatigue life could be screened out prior to running an expensive “clinically relevant” fatigue life verification study. METHODS: Two groups of NiTi devices were built; one group was not electropolished and the other group was electropolished (EP). All samples were tested at the same frequency but different strain amplitudes and the number of cycles to failure was measured for each group. The resulting fatigue life (S-N) curves were generated for each group of data. The two S-N curves were overlaid and the number of cycles at which they diverged from each-other was identified. RESULTS: The divergence of the two fatigue lifetime (S-N) curves reveals the maximum acceptable alternating strain amplitude for future accelerated fatigue failure testing of the device. CONCLUSIONS: Using the boundary conditions determined from this study, future design and process changes or improvements could be tested at an alternating strain equal to or less than this “divergent” strain to determine if the new design or process results in a shorter device fatigue lifetime.