William J. Parish

Will Parish is a Health Economist at RTI with expertise in behavioral health services research and financing. Dr. Parish currently is the project director for the Accountable Health Communities (AHC) Model Evaluation and the Value in Treatment-Opioid Use Disorder (VIT-OUD) Demonstration Evaluation. For both projects, he oversees a team of analysts and claims data programmers who work with multiple claims databases associated with Medicaid, Medicare fee-for-service, and Medicare Advantage populations. In addition, Dr. Parish has contributed to studies as a co-investigator on a National Institute on Alcohol Abuse and Alcoholism R01 research grant to develop a novel Bayesian technique for measuring alcohol exposure distributions in the United States that account for misclassification errors in self-reported survey data. Lastly, Dr. Parish has contributed to and led multiple small research grants funded through a partnership with an advocacy group to study the prevalence of unmet substance use disorder treatment needs among Medicare beneficiaries and barriers to accessing substance use disorder treatment in the Medicare population. This work builds off multiple groundbreaking research studies that highlighted barriers to opioid use disorder treatment access among Medicare patients.