One of the principal objectives of the Clean Air Act Amendments Act of 1990, contained in Title IV, is to control acid deposition by reducing the air emissions of sulfur dioxides (SO2) and nitrogen oxides (NOx) released by many fossil fuel-fired steam-electric generating utility units. A report recently issued by the National Acid Precipitation Assessment Program (NAPAP), called the Integrated Assessment (NAPAP IA), casts formidable doubts upon Title IV's efficacy by suggesting that the relationship between Title IV and the mitigation of the adverse effects of acid deposition in environmentally sensitive areas is too attenuated to warrant the nationally pervasive regulatory nature of Title IV. The purpose of this article is to compare the non-acid deposition-related external environmental cost benefits of Title IV with the internal costs of compliance. This article argues that, notwithstanding the external effects of reducing acid deposition, the non-acid deposition-related external cost benefits made possible by Title IV far outweigh the internal costs of complying with Title IV. Therefore, regardless of the issue of whether the intended scope and focus of Title IV is appropriate to control damage due to acid deposition, Title IV clearly has viable non-acid deposition-related cost justifications.