LOUISVILLE, Ky. (WDRB) --  A South Florida doctor alleges in a lawsuit that his former associates and Louisville-based Humana Inc. fraudulently over-billed the government’s Medicare Advantage program during a six-year period at two clinics.

The suit, filed in 2012 by Mario M. Baez, was not a matter of public record until Feb. 26, when a federal judge in South Florida unsealed the file.

Baez’s former business partner Dr. Isaac K. Thompson, of Delray Beach, Florida, agreed on March 4 to plead guilty to health care fraud in a criminal case that resulted from the allegations in Baez’s 2012 lawsuit, federal court records show.

Humana, which was not named in the Thompson criminal case, declined to comment on the Baez lawsuit, according the Center for Public Integrity, which first reported the unsealing of the case on March 4.

The U.S. Attorney’s Office in West Palm Beach, Florida, has been investigating Baez’s claims and considering intervening to “take over” the civil case against Humana and the doctors, according to December court filing.

Two other lawsuits have been filed against Humana “in connection with similar allegations at other clinics,” according to the December filing by the U.S. Attorney’s Office in West Palm Beach.

The filing also indicated that federal authorities are still investigating criminal violations.

In its annual report filed last month, Humana acknowledged receiving an "information request" from the U.S. Department of Justice civil division related to its Medicare Advantage risk-adjustment practices. However, Humana said federal authorities are not focused on the company in particular. 

"We believe that this request for information is in connection with a wider review of Medicare Risk Adjustment generally that includes a number of Medicare Advantage plans, providers and vendors," Humana said. 

Medicare Advantage is a managed-care alternative to traditional Medicare and is administered by private insurers like Humana.

Medicare Advantage has propelled Humana’s growth in recent years, and is one of the main reasons Aetna decided to buy the company in a pending $37 billion transaction.

Baez alleges that in 2009, he discovered that his colleagues were “upcoding” patients’ records by fraudulently adding ailments, such as major depression, to increase the monthly per-patient reimbursement that Humana would receive from the federal government. Most of the money was then passed on to the South Florida clinics, Baez alleges.

In his March 4 plea agreement, Thompson admits that from 2006 to 2010, he falsely diagnosed 387 patients with a chronic inflammatory disease of the spine, which in turn inflated Humana's per-patient payments from the federal government by $2.1 million.

The false diagnoses also increased the fixed amount that Thompson's clinic received from Humana to manage the patients' care -- which was about 80 percent of the money Humana received from Medicare, according to the plea. 

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