The innovation and diffusion of new technologies is in large measure responsible for the persistent rise in the cost of health care. The increasing cost of health care, in turn, will make cost-saving technologies more attractive. When cost-saving technologies lead to better or equivalent outcomes, their acceptance will not be controversial. However, the necessary conditions for the development and clinical acceptance of cost-saving technologies that might diminish the quality of health care have not been systematically considered. Indeed, as the clinical research enterprise has been focused almost entirely on quality-improving (or quality-neutral) innovations, new concepts may need to be introduced for quality-reducing innovations. Although the development of such therapies would, at least in some circumstances, increase overall societal benefits, replacing a standard therapy with a less effective one may conflict with deeply held values, such that conventional cost-effectiveness benchmarks might not apply. In addition, from a clinical research perspective, there are considerable ethical and methodologic hurdles that might impede the development of less expensive, less intensive therapies. In this article, using a hypothetical scenario, the authors consider economic, ethical, and research design issues concerning the innovation and diffusion of less effective, less expensive therapies and introduce 2 concepts—”decremental cost-effectiveness” and “acceptability trials”—that may in part provide a research framework for the study of “new and dis-improved” therapies.