Insurance exchanges will have a vital role in the marketplace, helping consumers shop for, understand, and purchase coverage. States can also use exchanges to shape the quality and cost of plans. The ACA calls for the creation of American Health Benefit Exchanges, which are expected to be the source of health insurance coverage for millions of Americans. Primary responsibility for establishing exchanges rests with the states, although the federal government will step in to create them in states that opt out. States that decide to establish an exchange will need to determine policy goals and governance structure; develop enrollment systems and IT infrastructure; and adopt plan rating, billing and other systems.