The government's Office of the Inspector General has  found that Boston's Brigham and Women's Hospital received $1.5 million  in overpayments because the hospital didn't fully understand Medicare billing requirements.

The Boston hospital is one of several hospitals across the country OIG recently discovered had overbilled.

According to a March 13 OIG report, Brigham and Women’s complied with Medicare billing requirements for 140 of the 359 claims that were reviewed. ‘However, the hospital did not fully comply with Medicare billing requirements for selected inpatient and outpatient claims. Specifically, 219 claims had errors, resulting in net overpayments totaling $1.5 million for calendar years 2008 through 2010.

These overpayments occurred primarily because the hospital did not have adequate controls to prevent incorrect billing of Medicare claims or did not fully understand the Medicare billing requirements,” according to the report.

Due to its findings, OIG recommended that Brigham and Women’s refund Medicare $1.5 million for the 193 incorrectly billed inpatient claims and the 26 incorrect outpatient claims. OIG also recommended that the hospital “strengthen controls to ensure full compliance with Medicare requirements,” according to the report.

Brigham and Women’s generally agreed with the findings except for five inpatient short stay claims, OIG noted.

Recently, several other hospital systems were also found by OIG to have overbilled Medicare, mostly due to inadequate training and inadvertent errors.

Last month, OIG found that Thomas Jefferson University Hospitals in Philadelphia received $43,000 in overpayments because it incorrectly billed for inpatient same-day readmissions.

“Jefferson did not always bill same-day readmissions in accordance with federal requirements," OIG noted in its report. "For four of the 133 same-day readmissions selected for our review, Jefferson incorrectly billed the second admission as a separate inpatient stay instead of a continuous stay based on the initial admission. These overpayments occurred because Jefferson did not have adequate training to review same-day readmissions and prevent incorrect billings.”

There was also a similar issue in Connecticut. According to another report last month, St. Vincent's Medical Center in Bridgeport, Conn., didn't fully understand Medicare billing requirements for 41 claims out of the 198 reviewed. The misunderstandings resulted in $284,773 in overpayments in 2009 and 2010, according to the report.

Last month, Carolinas Medical Center in North Carolina received nearly $6,000 in overpayments as well, however, OIG found that the reason was inadvertent keying errors by new coding staff and not a lack of training. The OIG report found that the hospital had errors in eight of the 73 brachytherapy Medicare claims reviewed.

According to a report issued by CMS last month, the total of alleged Medicare overpayments identified by recovery audit contractors (RAC) has reached $1.27 billion since October 2009.