ALEXANDRIA, Va. (AP) — The Justice Department is stepping into a long-running lawsuit against one of the nation’s largest nursing-home chains, accusing it of systematic Medicare overbilling.

The department announced Tuesday that it has intervened in a whistleblower lawsuit against Toledo, Ohio-based HCR ManorCare after a yearslong investigation. The initial accusations against the company were filed by a northern Virginia occupational therapist in 2009.

The lawsuit alleges that ManorCare routinely pressured administrators of its nursing homes, assisted living and rehab facilities to meet financial targets by billing for unnecessary care. The lawsuit says fragile patients who were recommended for hospice care were instead put on arduous rehab schedules to increase billing.

ManorCare, which also operates under the Heartland brand, denied wrongdoing and said the dispute revolves around providing care that exceeds government expectations.

The federal statement says ManorCare operates about 281 skilled nursing facilities in 30 states including Kansas.