Differential privacy has gained a lot of attention in recent years as a general model for the protection of personal information when used and disclosed for secondary purposes. It has also been proposed as an appropriate model for health data. In this paper we review the current literature on differential privacy and highlight important general limitations to the model and the proposed mechanisms. We then examine some practical challenges to the application of differential privacy to health data. The review concludes by identifying areas that researchers and practitioners in this area need to address to increase the adoption of differential privacy for health data. Categories and Subject Descriptors K.4.1 [Computers and Society]: Public Policy Issues —Privacy General Terms Documentation, Security, Human Factors. Keywords Differential privacy, Microdata, Anonymity, De-identification, Randomization.