David Gamage's primary research and teaching interests are in the areas of taxation, budget policy, and public finance. Gamage has written extensively on state-level tax and budget policy and on the economic theory of taxation. Professor Gamage also writes on the use of tax law to achieve social welfare and regulatory goals (such as the intersection of taxation and healthcare policy). During the 2010-2012 academic years, Professor Gamage was on teaching leave while serving as Special Counsel and Senior Stanley S. Surrey Fellow to the U.S. Department of the Treasury, Office of Tax Policy. In that position, Professor Gamage administered the individual income tax portfolio of the Treasury Department's Tax Legislative Counsel, thus overseeing the drafting of all individual income tax regulations as well as advising on new legislation and executive branch initiatives related to the individual income tax.