The GW Hospital was one of 32 medical centers that filed lawsuits against the Department of Health and Human Services last week, claiming they were shortchanged a total of nearly $12 million in Medicare reimbursement funds.

The hospitals assert that the Department of Health and Human Services incorrectly calculated how it doles out Social Security funds, according to court documents.

Reimbursements to GW’s hospital typically come in at higher rates because of its inner-city location and high number of low-income patients. Treatment for those patients is more expensive, because many do not receive primary care and tend to come to the hospital with more complicated conditions, said Barbara Williams, a medicare reimbursements specialist in the D.C. law firm Powers Pyles Sutter & Verville. Williams is not involved in the lawsuit.

The case is a follow-up to another case from five years ago, in which the U.S. District Court for D.C. ruled that the health department had flubbed payment calculations and underpaid Medicare providers. After the Centers for Medicare and Medicaid Services tweaked its formula following the 2008 ruling, medical centers claimed the new calculation actually took away even more funds.

The hospitals banding with GW include California-based Alameda Hospital, Texas-based Shannon Medical Center and Hawaii-based Kuakini Medical Center. Several other hospital coalitions filed separate appeals on the same issue, Williams said. She said the court could either combine the appeals into one case and rule on them together, or it could wait until the other lawsuits are complete before it makes a judgement.

Williams added that she predicts the case will take at least a year to be resolved.

The Centers for Medicare and Medicaid Services declined to comment, as the lawsuit is ongoing, spokesman Don McLeod said.

GW Hospital – which is mostly owned by the corporation Universal Health Services – also declined a request to comment on the lawsuit. The University holds a 20 percent stake in the hospital.