Average in-state tuition rates at public four-year institutions, compiled annually by the National Center for Education Statistics (NCES) through the Integrated Postsecondary Education Data System (IPEDS). This metric covers mandatory fees for full-time undergraduate students who meet state residency requirements. The national average masks significant state-by-state variations, ranging from under $6,000 to over $17,000 annually. Tuition rates are influenced by state appropriations (covering approximately 54% of educational costs), institutional costs, enrollment patterns, and state higher education policies. Historical trends show real costs increasing at 3.1% annually since 1990, outpacing inflation and wage growth. The data includes detailed breakdowns of institutional spending: instruction (31%), academic support (8%), student services (10%), research (11%), and administrative overhead (13%). This metric correlates strongly with student debt levels, enrollment patterns, and state-level economic indicators, serving as a key measure of higher education affordability and accessibility.