This project focuses on the development and application of formal computational and statistical models for the protection of patient information from re-identification. Unlike text de-identification, which leaves potential inferences to be exploited, these approaches provide explicit guarantees about the extent to which data can be linked to external resources for resolution of named patients. This project is mainly concerned with how patient information can be anonymized to support genome-phenome association studies. This project is sponsored, in part, by several U01 grants from the NHGRI/NIH and Canada and Australia.