Credit unions in the United States (US) are exempt (benefit from subsidies) from federal corporate income taxes, which are traditionally justified by their non-profit cooperative status and mission of meeting the financial needs of individuals of modest means. In recent years, the efficacy and fairness of these subsidies has been debated extensively as the traditional demarcation between banks and credit unions and their respective customer bases have blurred. To investigate how credit unions allocate subsidies to various stakeholders, we estimate a structural profit model for matched pairs of credit unions and commercial banks. We find that credit unions use most (approximately 90%) of their tax exemption for the benefit of their membership via above-market deposit interest rates.