The data that were reviewed in this article documented that in health systems, which manage behavioral health disorders independently from general medical disorders, the estimated 10% to 30% of patients with behavioral health service needs can expect (1) poor access or barriers to medical or mental health care; (2) when services are available, most provided will not meet minimum standards for expected outcome change; and (3) as a consequence of (1) and (2), medical and behavioral disorders will be more persistent with increased complications, will be associated with greater disability, and will lead to higher total health care and disability costs than will treatment of patients who do not have behavioral health disorders. This article proposes that these health system deficiencies will persist unless behavioral health services become an integral part of medical care (ie, integrated). By doing so, it creates a win-win situation for virtually all parties involved. Complex patients will receive coordinated general medical and behavioral health care that leads to improved outcomes. Clinicians and the hospitals that support integrated programs will be less encumbered by cross-disciplinary roadblocks as they deliver services that augment patient outcomes. Health plans (insurers) will be able to decrease administrative and claims costs because the complex patients who generate more than 80% of service use will have less complicated claims adjudication and better clinical outcomes. As a result, purchaser premiums, whether government programs, employers, or individuals, will decrease and the impact on national budgets will improve. Ongoing research will be important to assure that application of the best clinical and administrative practices are used to achieve these outcomes.