CMS has announced that the recovery audit contractors (RACs) demonstration program corrected over $1 billion of Medicare improper payments from 2005 through March 27, 2008. Approximately 96% of the improper payments ($992.7 million) were overpayments collected from providers (with 85% of the overpayments collected from inpatient hospitals), while the remaining 4% were underpayments repaid to providers.