A topic of long-standing discussion in Japan has been how to equitably merge the retirement plans for civil servants and private employees, which in the past have been managed separately. Recent legislation sought to unify social security pension schemes for all employees, by extending the coverage of the Japanese Employees’ Pension Insurance Scheme which covers private employees to include civil servants as well. We describe how Japanese social security pension schemes have evolved, the forces driving the merger of these plans, and what future prospects may be.