The competitive forces built into Part D have kept costs down. At an average of just $38 a month, premiums are 27 percent below where the government expected them to be. They’ve been essentially flat since 2009, according to the Kaiser Family Foundation.
Low premium costs, in turn, mean less taxpayer money for subsidies. In fact, Part D costs are 40 percent below where the Congressional Budget Office (CBO) initially predicted. Over the past six years, the CBO has lowered its long-term cost projections for Part D by hundreds of billions of dollars.