Medicare paid nearly 4,000 doctors and medical professionals more than $1 million apiece in 2012, including seven who received more than $10 million. Eye doctors were among the highest compensated, including one Florida ophthalmologist paid $21 million in 2012.

The disclosures were gleaned from a trove of $77 billion in payment data released by the government this morning that provides the first look at Medicare payments to physicians in more than three decades.

The massive data file covering 880,000 providers showed concentration at the top, with the doctors over $1 million receiving at least 13 times the $77,000 average paid by the program. The data showed that cancer doctors specializing in blood work and radiation are those best compensated by Medicare, each averaging over $360,000 in annual payments from the program for the elderly and disabled, which is the largest health-care payer in the U.S.

“This is an enormous event and momentous day and a long time in coming,” said Bob Kocher, a former special assistant to President Barack Obama for health care policy, in an interview. “What it’s going to help us do for the first time is figure out what these doctors actually do and what kinds of patients they actually see.”

While drug and hospital costs have been scrutinized, less attention has been paid to doctors’ fees, which accounted for about 12 percent of Medicare’s budget in 2012. Making the data available may allow the public and researchers to better identify fraud and waste by doctors in the $604 billion Medicare system.

More Heat

The data could also put more heat on doctors who engage in self-referral -- ordering up tests and procedures that are performed in their own clinics or in those in which they have a financial interest.

The data release has been lauded by consumer groups seeking to spotlight possible fraud or overuse and criticized by physicians, including the American Medical Association, whose head has said misinterpretation could ruin doctors’ careers.

Medicare payments to doctors were kept from the public after medical associations argued in the early 1980s that their release would violate physicians’ privacy. Last May, a federal judge lifted a 33-year-old injunction on the data following a lawsuit by Dow Jones & Co.

AMA Fought