Where are the Medicare savings coming from?

Loren Adler and Adam Rosenberg report:

…the disproportionate role played by prescription drug spending (or Part D) has seemingly escaped notice. Despite constituting barely more than 10 percent of Medicare spending, our analysis shows that Part D has accounted for over 60 percent of the slowdown in Medicare benefits since 2011 (beyond the sequestration contained in the 2011 Budget Control Act).

Through April of this year, the last time the Congressional Budget Office (CBO) released detailed estimates of Medicare spending, CBO has lowered its projections of total spending on Medicare benefits from 2012 through 2021 by $370 billion, excluding sequestration savings. The $225 billion of that decline accounted for by Part D represents an astounding 24 percent of Part D spending. (By starting in 2011, this analysis excludes the direct impact of various spending reductions in the Affordable Care Act (ACA), although it could still reflect some ACA savings to the extent that the Medicare reforms have controlled costs better than originally anticipated.) Additionally, sequestration is responsible for $75 billion of reduced spending, and increased recoveries of improper payments amount to $85 billion, bringing the total ten-year Medicare savings to $530 billion.

The full piece is here, via Arnold Kling.