The new health law encourages doctors, hospitals and insurers to team up in treating patients, but these groups already are at odds as they urge the government to set rules protecting their financial interests. At issue are accountable care organizations, which the Obama administration hopes will spring up around the country, initially treating Medicare patients but eventually other people as well. As envisioned, these networks of doctors and hospitals might work for the same organization or separately, sharing information about patients and financial responsibility for their care. But the ACO concept -- like others in the healthcare law that rejigger the financial relationships among providers and insurers -- was written broadly. Lawmakers left it to regulators to figure out how to put the provisions into practice.