From Peace Corps Wiki
Peace Corps or graduate school? Two unique programs offer the best of both worlds.
Peace Corps has established partnerships with colleges and universities across the U.S. that offer academic credit and financial incentives to Volunteers during or after Peace Corps service. Master's International allows you to incorporate Peace Corps service into a master's degree program at more than 40 colleges and universities. And our Fellows/USA program offers returned Volunteers scholarships or reduced tuition at more than 30 participating schools.
 Master's International Program
Master's International Program offers the unique opportunity to combine Peace Corps service with a master's degree program. Prospective students apply separately to Peace Corps and to a participating graduate school. Once accepted by both, students will study on campus, usually for one year, and then spend the next two years earning academic credit while working overseas in a related Peace Corps project. Most schools provide students in this program with opportunities for research or teaching assistantships, scholarships, or tuition waivers for the credits earned while serving in the Peace Corps.
Fellows/USA offers Volunteers who have returned home scholarships or reduced tuition in advanced degree programs. Some also receive housing allowances, paid employment, or health benefits. In return for these benefits, Fellows make a commitment to work in an underserved U.S. community as they pursue an advanced degree in a variety of disciplines. Fellows teach in public schools, work in public health facilities, and contribute to community development projects at nonprofit organizations. Volunteers can apply for the Fellows/USA any time after they complete their Peace Corps service.
 External Links
Educational Benefits Official US Peace Corps Website