The OIG reports that 20 high-use counties with 6% of Medicare beneficiaries accounted for 16% of Part B spending on ultrasound services in 2007. In addition, the OIG believes that 3.2 million ultrasound claims (almost one in five nationwide) might be inappropriate. The OIG recommended that CMS monitor ultrasound claims data to detect and review questionable claims prior to payment, and take certain action when providers bill for high numbers of questionable claims; CMS concurred.