3. Lack of patient incentives
There's no requirement for patients to be actively involved in joining an ACO. Rather, they'll be affiliated with such an organization "probably based on the affiliation of their primary care physician" and will probably have no incentive to cooperate with strategies to reduce cost.
4. Cost management confusion
Providers lack actuarial or insurance expertise, and so are unlikely to be able to successfully manage health costs of a population.
5. Cost shifting
Physician markets will continue to be consolidated through hospitals' acquisition of practices, forcing private insurance costs higher through cost-shifting.