The development of pension systems for public-school teachers in the United States has been both recent and rapid. A beginning of their establishment was made in the latter part of the nineteenth century, and today, after 30 years, very few States are without some form of a teachers' pension system. The purpose of the present study of pension systems for public-school teachers in the United States is twofold: (1) To discover the tendencies in the development of teachers' pension systems in the United States; and (2) in so far as possible, to formulate criteria by which to evaluate any particular teacher pension system. This bulletin is organized in five chapters, covering: (1) Introduction, including the problem of the thesis, plan of treatment, and sources of data; (2) Classification and administration of local and state-wide public-school teachers' pension systems, administration of pension systems, pensions systems from the standpoint of contribution, tendencies in organization and administration, and criteria for evaluating any particular teacher pension system with regard to organization and administration; (3) The financing of teachers' pension systems, including sources of funds, methods of pension financing, actuarial investigation, accrued liabilities, tendencies in pension financing, and the criteria for evaluating the pension system with respect to pension financing; (4) The teacher's contribution--policies and tendencies, 1894-1924, including optional versus compulsory membership, methods of assessing the teacher's contribution, the amount of the teacher's contribution, the management and administration of teachers' contributory funds, summary of tendencies with respect to the teacher's contribution, and the criteria for evaluating a system with respect to the teacher's contribution; (5) The benefits of teachers' pension systems--superannuation benefits, disability benefits, withdrawal benefits, refunds in case death occurs before retirement, summary of tendencies with respect to the benefits of teachers' pension systems and the criteria for evaluating a pension system's benefits; and (6) Conclusion, being a summary of tendencies and criteria. Includes four appendices and a bibliography. (Contains 29 tables and 38 footnotes. Tables also contain footnotes.) [Best copy available has been provided.]