Looking at the top Medicare billers in today's massive data dump, the big dollar amounts are hard to ignore. The top 10 doctors alone received a combined $121.4 million for Medicare Part B payments in 2012. But not all of these doctors are pocketing millions. A clear trend emerges from the data and from interviews with these physicians: The high cost of drugs is a huge driver of the robust Medicare payouts. Indeed, slightly more than half of the Medicare payments to these 10 doctors — $61.9 million in total — went toward drugs and "other costs."