Many countries around the world are partly prefunding their otherwise pay-as-you-go (PAYG) financed social security systems by establishing or further developing existing public pension reserve funds (PPRFs). Most OECD countries have put in place internal and external governance mechanisms and investment controls to ensure the sound management of these funds and better isolate them from undue political influence. These structures and mechanisms are in line with OECD standards of good pension fund governance and investment management. In particular, the requirements of accountability, suitability and transparency are broadly met by these reserve funds. However, some specific details of the funds’ governance and investment management could be improved in a few countries, such as enhancing the expertise in the funds’ governing boards and constraining discretionary interventions by government. Such reforms will ultimately raise the long-term investment performance of the funds and the solvency of social security systems.