Accountable care organizations (ACOs) are an operational and reimbursement healthcare model that is intended to help achieve the dual goals of managing healthcare costs while improving quality of care. Evidence-based guidelines for care management hold great potential for helping ACOs meet these goals in several ways, such as by promoting best practices, by assisting with payment allocation among providers of care, and by facilitating communications among providers and between providers and patients. This paper presents clinical referral guidelines as an example of how evidence-based guidelines can affect and enhance the accountable care concept.