This whitepaper outlines the top selection criteria for selections a MEMS foundry. It might seem arcane for those in the semiconductor industry, but the fact is that there is no common MEMS processing platform that is shared between foundries. The MEMS industry does not have an equivalent to the Simulation Program with Integrated Circuit Emphasis (SPICE) model for particular process models. Process development for MEMS products is very much product and design specific. The MEMS industry is coming to the realization that there will always be multiple process platforms and that these can serve as a means of differentiation between foundries. The high risk and lengthy (read: costly) development of MEMS processing is not the core business of large semiconductor foundries. These foundries are more ROI driven along a set of predictable parameters; wafer size, process steps/mask levels and production volumes. Smaller foundries specializing in MEMS processing are willing to conduct early-stage process development for proof-of-concept against non-recurring engineering charges (NRE) and accept small batch orders for development and production. For a MEMS product company, the foundry selection process should include foundries that have the capability to provide services for prototyping, process development, and high-volume manufacturing. It is also important to select a foundry that can offer intelligent design and process feedback, and that cooperates on the processing specification to ensure manufacturability and high yielding products.