Ernesto A. Montaner, the eldest son of a prominent Cuban exile family who stole millions from Medicare, implored a Miami federal judge Wednesday to give him a sentencing break because of his advanced age, poor health and time already spent behind bars.

But U.S. District Judge James Lawrence King showed no sympathy for the 71-year-old Montaner, who attended court in a wheelchair.

The judge slapped him with a maximum five-year prison sentence for defrauding the taxpayer-funded healthcare program for the elderly and disabled, saying he conspired to pay “massive amounts of kickback” money for patient referrals to his Miami-Dade chain of rehabilitation clinics.

King also ordered Montaner, who had fled Miami to Costa Rica to avoid an impending indictment before his arrest in 2010, to pay Medicare more than $2.8 million.

“I feel so much regret for my choices,’’ Montaner, who has been in custody since early last year, said in court. He added that he let down the dozens of relatives and friends who attended his sentencing.

“I know I did wrong,” said Montaner, who pleaded guilty earlier this year. “I know I committed the crime of Medicare fraud. I pray for your understanding and forgiveness.’’

What made Montaner’s Medicare fraud case different from so many others was that his son — whom Montaner had brought into his clinic business — testified against the father before a federal grand jury and was almost going to be a witness again at his sentencing.

A prosecutor had planned to call Ernesto A. Montaner Jr., a cooperating witness already convicted of Medicare fraud, to the stand to show that the father was in charge of four physical therapy clinics. Establishing the father’s leadership role would boost his sentence. But the elder Montaner shifted blame to his son, asserting that Montaner Jr. was in fact responsible for running the clinics.

Montaner’s defense attorney and two of his daughters, who are lawyers, told the judge that pitting the son against his father placed a terrible strain on the family.

“I’m glad it’s over,” Marlene Montaner said outside the courtroom, after asking the judge to release the elder Montaner immediately so that he could be home for Father’s Day on Sunday.

Montaner’s defense lawyer, who had challenged the characterization of his client’s management role, condemned the prosecutor’s tactics, arguing that the U.S. attorney’s office “forced” the son’s “hand” to testify against his father before the grand jury and to use him again for the sentencing.

“This has been a very unfortunate situation for this family,” the father’s lawyer, Marc Seitles, told the judge. “What the government was doing was something it shouldn’t have done. This was not done with any malice, but it was done.

“He is here, due in part, to the compelled testimony of his son,” Seitles said. “No family, no defendant, should have to endure that.”

But Seitles and his client, in the days before sentencing, dropped their challenge to the leadership assertion, making it unnecessary for the son to testify again.

Assistant U.S. Attorney Ron Davidson mocked their legal move. “We are here because the defendant recruited his own flesh and blood into the fraud,” Davidson said in court. “This man corrupted and ruined the life of his own son.”