The federal government has told Maryland to refund $10.9 million in improperly claimed Medicaid payments made to providers of home care to seniors.

An audit by the U.S. Department of Health and Human Services' Office of Inspector General shows 20 percent of a sample of 100 reviewed cases should not have been eligible for payment under the taxpayer-funded federal program that provides health care for low-income Americans. Those cases include personal care aides who weren't qualified to perform services, unapproved or missing care plans and billing for services that should not have been authorized.

The audit covered $67.2 million in payments made between July 2008 and June 2010, 16 percent of which the government now wants back.

HHS spokesman Don White said it isn't possible to tell from the audit whether any fraud was committed.

"What we do know is the state of Maryland misused more than $10.8 million of federal taxpayer money," White said.

"The state of Maryland did not comply with the rules it had to comply with in order to receive federal money."

The improper claims were part of Maryland's Medicaid Home and Community-Based Services Waiver for Older Adults, which provides in-home care for low-income seniors who otherwise would be in a nursing home or assisted living facility.

In 15 of the 100 cases sampled, the personal aide didn't meet one or multiple qualifications to administer the services Medicaid paid for. Four of the aides didn't have a valid criminal background check, 11 didn't have a CPR certification, and one wasn't certified to hand out medication but did so anyway.

The audit showed four of the health care providers billed Medicaid for more hours of service than approved. For example, one claim reviewed by the inspector general showed that a provider billed for 11 hours of care in a single day when it was authorized to provide only eight.

The audit also found that one of the claims for payment was not supported by a time sheet.

Chuck Milligan, Maryland's Department of Health and Mental Hygiene deputy secretary for health care financing, said the state plans on paying the federal government back by June 30, the end of Maryland's fiscal year. He said the money would come from parts of the state's Medicaid budget where spending growth was slower than expected.

He said that while the federal government is entitled to the $10.9 million, the problem was improper documentation of services, not fraud.

That isn't the first time Maryland has run into trouble with the way it administers Medicaid. In 2011, auditors found that the state had paid $2.5 million to more than 300 low-income Marylanders who had died but continued to receive checks.