Yesterday's announcement by the Department of Health and Human Services, setting firm targets for shifting Medicare away from fee-for-service payments, has for the most part generated positive reviews. That makes sense -- that payment structure provides incentives for excess care, and HHS is right to move past it. But that shouldn't mean the Medicare agency gets a pass on the details. There are a few reasons to wonder just how serious HHS is about these changes. First, the alternative payment structures highlighted by HHS haven't yet succeeded in pilot programs. The whole point of changing Medicare's payment method is to cut costs while increasing (or at least not hurting) quality of care.