The Clean Air Act is one of Congress' greatest success stories--a major piece of legislation, passed in the context of environmental and public health crises, that has driven technological change through regulation that has dramatically improved air quality even in a prolonged period of economic growth. However, in the context of climate change, despite many efforts since the 1990s, the Clean Air Act has not proven to be a successful legislative tool, due to complex obstacles in the statutory language and a trend in Supreme Court jurisprudence--leading up to and including the June 2022 decision in West Virginia v. EPA--that is skeptical of administrative agency authority.Then, in August 2022, the Inflation Reduction Act (IRA) broke through the congressional logjam. The IRA is the most significant piece of climate legislation in U.S. history, with a commitment of $369 billion in spending on energy security and climate change programs over the next decade. Research groups have estimated that the Act will result in major reductions in U.S. greenhouse gas emissions--nearly 40 percent below 2005 levels. The IRA is spending bill, not a regulatory one, reflecting a highly constrained legislative environment in which filibuster rules and partisan intransigence mean that policy-by-spending is the only feasible option, not only for environmental issues but a broad range of social programs and priorities. Yet the IRA--despite these characteristics and the legislative and judicial context--will have important regulatory consequences.The Clean Air Act gives the Environmental Protection Agency (EPA) statutory authority to set strict standards that are, in part, based on a determination of what clean technologies are already available--through the “adequately demonstrated” standard in Section 111 and other requirements to balance environmental benefits with cost and/or technological feasibility. As the IRA works to lower costs and increase the market share of clean energy technologies, EPA will, by the end of the 2020s, be able to promulgate stronger technology-based standards--both more stringent in nature and more legally secure--than would otherwise be the case. Despite the limitations of spending policy, the IRA can play an important role in bringing about an effective energy transition, allowing the EPA to return to the original idea of “technology forcing” in the Clean Air Act and consolidate, through prescriptive regulation, the technological advances ushered in by federal spending programs.