A new report by the HHS Inspector General found that federal payments for Medicare Part D catastrophic coverage, which pays 80% of drug costs after a beneficiary has spent a certain amount annually, surpassed $33 billion in 2015, more than triple the amount paid in 2010. Most of the rise is due to increased spending on drugs that cost $1,000 or more a month, several of which came on the market in the last couple of years, according to the Inspector General. Just 10 drugs accounted for a third of Part D catastrophic-coverage drug spending in 2015. Changes in how the drugs are taken by consumers have also left the catastrophic program with higher costs. About a decade ago, prescription spending slowed as more generic products came on the market and fewer new blockbuster drugs were introduced. Until a few years ago, many of the most expensive medications were not available in tablet form, according to Juliette Cubanski, associate director of Medicare policy at the Kaiser Family Foundation. "As more of these specialty drugs become available in [tablet] form, they are more likely to be covered under Medicare part D," notes Cubanski. "And that means the cost of these drugs is covered the way that other, less expensive medications are [also] covered by Medicare."