The sentence is one month in jail for every $1 million he embezzled.
Nadel, 77, was found guilty of cheating elderly retirees out of their money, The New York Daily News said. He was convicted of securities, mail and wire fraud.
Nadel's lawyer had asked for a sentence of no more than five years, saying that a longer stint in jail would effectively be a death sentence.
Nadel may actually end up joining Bernard Madoff in the Butner Federal Correctional Complex in North Carolina.