On June 14, the American Medical Association (AMA) released its third annual report card for insurers, finding that 20 percent of claims are processed inaccurately.  Of the seven insurers examined for the report, Coventry Health Care Inc. had the highest claims processing accuracy rating at 88 percent while Anthem Blue Cross Blue Shield had the lowest at 74 percent.  The AMA projects that achieving 100 percent accuracy in claims processing would save doctors and insurers $15.5 billion annually.

From the report:

The American Medical Association (AMA) National Health Insurance Report Card (NHIRC) provides physicians and the general public a reliable and defensible source of critical metrics concerning the timeliness, transparency and accuracy of claims processing by health insurance companies. Billions of dollars in administrative waste would be eliminated each year if third party payers sent a timely, accurate and specific response to each physician claim.

Full report: 2010 National Health Insurer Report Card (PDF | 89 KB) 

American Medical Association. (2010). 2010 National Health Insurer Report Card.