This post is co-authored by Aaron Carroll and Austin Frakt.

We’ve written so many times on how raising the Medicare eligibility age to 67 is a bad idea that we hesitate to do so again. (See the FAQ.) But a recent revision by the CBO of federal savings it would generate compels us to do this one more time.

Implementing this option would reduce federal budget deficits by $19 billion between 2016 and 2023, accord to new estimates by CBO and the staff of the Joint Committee on Taxation (see Table 1). That figure represents the net effect of a $23 billion decrease in outlays and a $4 billion decrease in revenues over that period. The decrease in outlays includes a reduction in federal spending for Medicare as well as a slight reduction in outlays for Social Security retirement benefits. However, those savings would be substantially offset by increases in federal spending for Medicaid and for subsidies to purchase health insurance through the new insurance exchanges and by the decrease in revenues.

Do you get that? Phasing this in starting in 2016 could save $19 billion over the next 8 years. That’s less than $3 billion a year. That’s… insane.

Why isn’t it more? Well, once again, the more people you kick of Medicare, the more you get on Medicaid. That increases federal expenditures. More people will also need exchange insurance, too, which means more people needing subsidies. That will also increase federal expenditures. These expenditures reduce the savings to the federal government from the $63.5 billion it would have cost to cover the 65 and 66 year olds to only $23 billion in savings.

And we’re not even counting the increase to state expenditures for the added Medicaid, the increased cost to employers who have to provide insurance, the increased cost to all Americans in higher premiums for adding those elderly people to the private risk pools, or the increased out of pocket expenses to those seniors. (We covered these costs in prior posts.) If this was a bad deal before, it’s worse now.

The last time the CBO estimated the savings from increasing the Medicare eligibility age, they pegged the savings to the federal government at $113 billion over 10 years. The new report has the savings as much, much less. Why? It turns out the CBO made a bit of a mistake last time*: