Marc Goldwein of the Committee for a Responsible Federal Budget argues that raising the Medicare eligibility age shouldn’t be cause for alarm. His argument assumes that PPACA will remain in place, and that moving from 65 to 67 as the eligibility age will do little more than shift a number of older workers onto the subsidized insurance exchanges:

Criticisms of raising the Medicare age are not only off base, but they obscure the two major benefits of such a policy. First, as suggested above, raising the age will lead to much better targeting of limited government resources.
Currently, pretty much everyone over age 65* receives the same effective insurance subsidy from the government — regardless of age or income. But Medicare’s costs are rising to unaffordable levels, and will have to be cut. Rather than reducing benefits across-the-board, raising the Medicare age does so in a very targeted way. For one, all reductions are targeted at the youngest of the Medicare population — those who tend to be in the best health and are most able to work. And as we explain above, it is not as if they would be thrown to the dogs. The lowest income individuals would continue to receive free heath care through Medicaid. Those of more moderate income would receive subsidized health care in the health exchanges, with subsidies linked directly to income. And even those of higher incomes would still benefit from many of the coverage provisions under health reform.
In addition to better targeting Medicare, increasing the age would have positive labor market effects. Many people make their retirement decisions based upon the Medicare eligibility age, and increasing it would likely encourage longer working lives. As we’ve explained in the past, longer working lives would accelerate economic growth, increase revenue collection, and improve overall retirement security.

I’d be curious to see the impact of raising the Medicare eligibility age if PPACA were repealed and replaced by a package of Medicare reforms modeled on Rivlin-Domenici plan and a flat health credit for under-65s, a policy advocated by Yuval Levin and Ramesh Ponnuru and others.