One of the major reasons providers give for not implementing promising quality-enhancing interventions (QEI) is that no "business case" for quality has been made. This article clarifies the concepts of the business case for quality and the related economic case for quality and identifies the perspectives of the various actors in health care financing, production, and consumption decisions. A methodology to evaluate the business case for quality from the perspective of payers and providers is presented. The article then uses implemented QEIs to show how a pay-for-performance (P4P) program can alter the business cases for payers and providers. Specifically, the P4P programs described in this article allow a provider to implement a QEI with the financial alignment of the payer in order to achieve financial and non-financial benefits. In some cases, providers and payers may be able to establish P4P programs providing net benefits for both parties.