Community colleges are increasingly being pressed to demonstrate efficiency and improve productivity even as these concepts are not clearly defined and require a significant set of assumptions to determine. This paper sets out a preferred economic definition of efficiency: fiscal and social cost per degree. It then assesses the validity of using IPEDS data to calculate efficiency for the community college system. Using IPEDS, I estimate the fiscal cost per associate degree at $52,900 for comprehensive community colleges and $42,740 for vocational colleges (in 2008 dollars); the social costs per degree are $71,610 and $56,930, respectively. The community college sector has become more efficient over time: fiscal and social costs per degree are lower in real terms in 2008 than they were in 1987. However, two issues are important to the validity of IPEDS: the ability to adjust for differences in student ability and the way that transfer patterns are incorporated. This paper addresses both of them. Total Annual Expenditures: Community College Sector is appended. (Contains 6 figures, 3 tables, and 44 footnotes.)