Medicare overpaid physicians $6.7 billion in 2010 for evaluation and management services, HHS’ Office of Inspector General said in a study released Thursday. The overpayments, which allegedly stemmed from incorrect coding and poor documentation, accounted for more than one-fifth of the $32.3 billion the CMS paid for E/M services that year. E/M services are basic patient health assessments performed at a physician’s office or clinic.

In a podcast, OIG officials Dwayne Grant and Rachel Bessette said they conducted the most recent study based on preliminary findings from 2012. In that report, the government found E/M services are “vulnerable to fraud and abuse” and that upcoding—billing Medicare for visits at higher, more expensive levels than they should’ve been—was rampant from 2001 to 2010. However, the agency was not able to discern if those E/M payments from its initial 2012 study were inappropriate.

“These higher level codes represent more complex visits, and higher reimbursement rates for physicians,” Bessette said in the podcast, talking about why the OIG re-evaluated the issue. “We also identified nearly 1,700 high-coding physicians who consistently billed these higher level codes in 2010.”