It is a dilemma facing practices around the country as the U.S. begins a transition toward new ways of paying for healthcare. Insurers are increasingly targeting the traditional system that has paid hospitals and doctors for each service provided (rewarding them for more care but not better results). But to effect these changes, doctors often must make a major financial commitment. That means upgrading their information-technology systems, adding support staff and getting special training to do the kind of outreach and coordination that make a practice a "medical home."