Managing the risks of accountable care.

Hospitals and health systems should assess the risks of participation in Medicare's Shared Savings Program before deciding whether to participate: Start-up costs will likely be prohibitive. The ACO will lack key tools needed to drive down unnecessary medical costs. Participating providers would have to accept significant downside risk for costs over which they have no control. ACOs generating significant savings in a program year would still face numerous preconditions to-and limitations on-payment.