HHS' inspector general's office in Miami Lakes, Fla., is investigating four HealthSouth Corp. facilities for allegedly submitting improper or fraudulent claims to Medicare and Medicaid.

The Birmingham, Ala., operator of inpatient rehabilitation hospitals said in a filing with the Securities and Exchange Commission that all four hospitals use the same Medicare administrative contractor, Cahaba Government Benefit Administrators.

The four unnamed hospitals represent about 3.8% of the company's consolidated net operating revenue, according to the filing. The company said it is “cooperating fully” with the investigation.

It added that the subpoenas requested information on a number of HealthSouth policies and procedures relating to marketing functions, pre-admission screenings, post-admission physician evaluations, patient assessment instruments and individualized plans of care.

The government also is seeking to determine whether HealthSouth complied with the “Medicare 60%” rule, which requires at least 60% of patients to have at least one of the specified conditions that allow a facility to qualify for higher inpatient rehabilitation reimbursement rates rather than lower acute-care payments.

Among the documents requested were complete medical records for 100 patients treated at the four facilities between September 2008 and June 2012.

In research notes, analysts did not expect the inquiry to have a significant effect on the company, and noted that it's unclear whether the subpoenas are part of a whistle-blower suit or the inspector general's 2013 work-plan, which stated its intent to focus on practices at inpatient rehabilitation facilities.

The subpoenas follow a separate June 2011 request from the Dallas inspector general's office regarding possible False Claims Act violations at HealthSouth Hospital of Houston, a long-term acute-care facility. The hospital was one of eight that HealthSouth had agreed to sell to LifeCare Holdings, Plano, Texas, but it was eventually dropped from the deal.