Editors' Summary: The permit program was one of the most significant additions of the 1990 Clean Air Act Amendments. The full potential of the Act will not be realized without an effective permit program. In the April 1991 issue of ELR, one of the principal participants in developing the permit and enforcement titles of the Amendments discussed the key elements of those titles. The author of that article noted that the effectiveness of the permit title will be largely shaped by EPA's implementing regulations, which EPA proposed in early May of 1991. This Article discusses the highlights of EPA's proposed permit regulations. The author, the principal EPA Office of General Counsel attorney responsible for the Clean Air Act permit program, outlines the advantages of a permit program, discusses EPA's development of the proposal, and analyzes the major provisions of EPA's proposal.