In a brief interview, McCray said both clinics are ''not legit,'' but he declined to talk further.

Detailed billing records for McCray are unavailable because of federal healthcare privacy laws.

Manassas' owner, Pedro Antonio Colls, declined comment for this story several times.

At ORD Medical Center, a receptionist recently told The Miami Herald that the clinic was no longer providing HIV infusion treatments because Medicare recently stopped paying its claims. The owner, Osmany Rodriguez, did not return calls for comment.

HUMANA NETWORK

Both clinics are part of Humana's Medicare network in South Florida. A spokesman confirmed that the managed care provider recently stopped paying the two Miami-Dade clinics' Medicare claims for infusion treatments.

``The reason is that the clinics were billing for [infusion]

services they were not providing to Humana members,'' said company spokesman Mitchell Lubitz.

Another man accompanying McCray to Manassas and other Medicare-licensed infusion clinics in recent months was Wendell Jackson, 55, of Miami. He received his Medicare disability number on Feb. 25, 2002, authorities said.

Since then, healthcare clinics have paid kickbacks to Jackson in exchange for using his Medicare number to bill the system for nearly $1 million in phony HIV infusion treatments, according to federal claim records and authorities.

Broward court records show Jackson was jailed in June for violating his probation on a grand-theft conviction involving stealing deep fryers from a warehouse. He violated his probation after testing positive for cocaine use and was sentenced to 18 months in prison, according to court records.

His lawyer, Dione Trawick, a Broward assistant public defender, said Jackson did not want to be interviewed for this story.

McCray, Jackson and other professional patients continue to slip through the cracks because they rotate from clinic to clinic with impunity.

The U.S. attorney's office in Miami said it has not made patients a priority because it's more interested in taking down offenders higher up in a fraudulent Medicare operation.

But as the FBI and Health and Human Services might be catching more Medicare-licensed operators and their doctors, the patients continue to sell their numbers to other scofflaw clinics that pop up.

In other instances, they steal Medicare patients' numbers. At Tamiami Medical Center in Hialeah, a habitual felony offender named Justo Padron became the president in 2006. He and his associates filed a total of 12,290 Medicare claims for immunoglobulin and other HIV infusion drugs. The total bill: $7.4 million. Medicare paid the clinic $2.4 million.

When FBI agents confronted him about more than $355,000 in Tamiami's Wachovia bank account last year, Padron said he didn't know anything about it and let them have the money.

But before prosecutors could indict Padron last November, a nine-foot alligator killed him. He had jumped into a lake as he tried to escape police after an attempted car theft in a parking lot at the Miccosukee Resort and Convention Center in West Miami-Dade.

Padron's death may have been spectacular, but the 36-year-old felon with more than a dozen Florida arrests for burglary, robbery and drug possession was a typical con artist in the underworld of Medicare fraud.

COMPUTER SOFTWARE

All of his clinic's claims were false, said federal prosecutors, who targeted his successor, Christian Vasquez, 25. Vasquez was sentenced in January to more than three years in prison for charging $1.1 million in fraudulent Medicare claims.