Carla K. Johnson, AP

One in five medical claims is processed inaccurately by commercial health insurers, often leaving physicians shortchanged, according to the nation's largest doctor's group. The American Medical Association recently released its third annual report card on insurers, showing that private insurance companies matched their payments to what they agreed to pay doctors about 80 percent of the time. The AMA has seen dramatic improvement from private insurers, said Dr. Nancy Nielsen, immediate past president of the group.

The AMA report card is an effort to reduce the cost of claims processing for doctors. As much as $210 billion is spent annually just to process insurance claims. Robert Zirkelbach, a spokesman for America's Health Insurance Plans, said it takes both sides — insurers and doctors — to process claims accurately and quickly. Many doctors don't submit claims electronically or promptly, he said.

“Government data shows that soaring medical costs — not health plan administrative costs — are the key drivers of rising health care costs,” Zirkelbach said in a statement responding to the AMA report card. The percentage of premiums going toward administrative costs has declined for six straight years, he said.

The AMA estimates that increasing the industry's accuracy to 100 percent would save doctors and insurers up to $15.5 billion a year. The group is meeting in Chicago in its first annual meeting since the passage of President Barack Obama's health care overhaul.

Even though Medicare pays doctors accurately, the AMA is unhappy with the way the Medicare system sets payment rates for doctors and has been lobbying for Congress to fix Medicare's reimbursement formula.

AMA President James Rohack said that both Democrats and Republicans need to step up and fix this problem permanently. Medicare said it will hold doctors' claims through Thursday, giving lawmakers more time to prevent a 21 percent cut, required by a 1990s deficit reduction law Congress has routinely waived in the past. The fix, already approved by the House, is pending in the Senate. The cut was technically required as of June 1, but Medicare has been holding claims in hopes lawmakers will resolve the issue.