So, what’s in the plan? You need to distinguish between the first decade, before the phasing out of Medicare as we know it begins, and after.
The first decade
In the first decade, the big things are (i) conversion of Medicaid into a block grant program, with much lower funding than projected under current law and (ii) sharp cuts in top tax rates and corporate taxes.
Is this a deficit-reduction program? Not on the face of it: it’s basically a tradeoff of reduced aid to the poor for reduced taxes on the rich, with the net effect of the specific proposals being to increase, not reduce, the deficit. Yet Ryan claims a big deficit reduction, via two big “magic asterisks”. First, he insists that the tax cuts won’t reduce revenue, because they’ll be offset with unspecified “base-broadening”. Here’s the CBO explanation:
The path for revenues as a percentage of GDP was specified by Chairman Ryan’s staff. The path rises steadily from about 15 percent of GDP in 2010 to 19 percent in 2028 and remains at that level thereafter. There were no specifications of particular revenue provisions that would generate that path.
Howard Gleckman of the Tax Policy Center calls these unspecified sources of revenue “mystery meat”, and strongly suggests that nothing like this would actually happen.