In each case, important potential gains in social welfare are noted, with an emphasis on key choices that must be made by those implementing the blueprint set out in the ACA. Gains in coverage among people with mental and substance use disorders are intertwined with the problems of poverty, illiteracy, and social isolation. Special efforts will be required to engage and enroll this deprived and frequently costly population. McGuire and Sinaiko explain that competitive insurance markets have functioned especially poorly in providing coverage to people at elevated risk of mental health and substance use problems. They review measures that might be adopted by new health insurance exchanges to mitigate historical failures in private insurance. The analysis presented by Garfield and colleagues highlights that gaps in services will remain despite coverage expansion, particularly for social supports that are not likely to be covered by private health insurance. Funding for wraparound services will continue to be important. Finally, Druss and Mauer suggest improvements in the infrastructure to promote improved mental health care within newly created medical homes and accountable care organizations. They call for development of a broader range of quality measures in mental health and the use of information technology by specialty providers.