The growth over the last decade of the for-profit sector of higher education (also known as the proprietary sector) has been well documented. In 1999, for-profit colleges and universities enrolled approximately 629,000 students, or a little over 4 percent of the nation's 15.2 million students. By 2009, this sector had increased to 2.2 million students, or almost 11 percent of the nation's 21 million college students. This gain in market share came at the expense of both public and private not-for-profit colleges. With this growth has come increased scrutiny of the sector, driven in large part by the perception that at least some students attending for-profit colleges are not receiving an adequate education for the money they spend. The scrutiny has come from both the media, which has covered alleged abuses perpetrated by some of the for-profit institutions, and from government. In response, the US Department of Education has issued a series of regulations aimed, at least in part, at reining in some of the alleged abuses. One set of regulations in particular, called the "gainful employment" rules, has received more attention than all the others combined. In this article, the author provides a background on the for-profit sector, an explanation of the proposed gainful employment regulations, and an analysis of their likely impact on US higher education more generally. (Contains 2 figures, 1 table and 14 resources.)