The GAO has issued a report analyzing trends related to high-expenditure Medicare Part B drugs, which are drug commonly administered by a physician or under a physician's close supervision in physicians' offices and hospital outpatient departments. The report provides data on: (1) the highest-expenditure Medicare Part B drugs in 2010 and utilization and spending trends for these drugs, and (2) nationwide spending for the total U.S. population for these drugs and Medicare's share of this spending. Among other things, the GAO found that the 55 highest-expenditure Part B drugs represented $16.9 billion in spending in 2010, or about 85% of all Medicare Part B drug spending. Most of these 55 drugs increased in expenditures, prices, and average annual cost per beneficiary from 2008 to 2010. Spending attributable to Medicare beneficiaries accounted for the majority of the estimated total U.S. spending for 35 of the 55 highest-expenditure Part B drugs in 2010.