The State of Connecticut is currently populating an All Payers Claims Database (APCD) which will hold all healthcare claims data for residents of Connecticut. The APCD will be a valuable resource for the study of healthcare delivery, costs and outcomes. It is also a potential resource for the study of health disparities in Connecticut. However, since very few healthcare claims records include the race and ethnicity of the beneficiary (approximately 3%), their use for the study of health disparities is very limited. The imputation of race and ethnicity in these claims data would greatly increase the value of the data held in the APCD and may lead to better healthcare outcomes for CT residents. Currently no model exists to impute race and ethnicity in CT healthcare claims. This project aims to use previously existing CT birth records data held by the Department of Public Health (DPH) to produce an imputation model that can be used to impute race and ethnicity in CT healthcare claims, thereby greatly increasing the utility of the data in the CT APCD. In addition, the model created for this project can be then extended for use in other states, increasing the general utility of healthcare claims. (This is joint work with Robert Aseltine and Yishu Xue).