Hospitals and doctors are pushing back against an Obama administration initiative that urges them to create accountable care organizations to coordinate the care of groups of Medicare patients. The voluntary program seeks to save money and improve treatment. But the healthcare providers say the rules proposed for the initiative are too onerous and the financial incentives too weak, and that they will participate only if the program gets a major revamp. The deadline for response to the proposal is June 6, but healthcare providers have already been unusually vocal in their complaints. "It's pretty much a nonstarter as structured," said Anders M. Gilberg, an official at the Medical Group Management Association. Jonathan Blum, deputy administrator of the Centers for Medicare and Medicaid Services, said in a statement that the agency has been "actively seeking input at every stage of the rule-making process, and we're confident that the final rule will reflect the valuable input we've received."