For years, Ramos was the prime suspect in the suspected abduction of Etan Patz, who disappeared while walking to his school bus stop.
A Luzerne County judge handed down the sentence Thursday against the 70-year-old Ramos, who was convicted in January of providing false information to prison officials.
A New Jersey man, Pedro Hernandez, has since been charged.
A civil court held Ramos responsible.
Ramos denies involvement.
He completed a 27-year sentence on unrelated molestation charges in 2012.
Hernandez had been tentatively set to go on trial in April in the case surrounding Etan Patz, but a judge recently said he now anticipates the trial starting in September.
Six-year-old Etan disappeared while walking to his school bus stop in 1979. He was one of the first missing children to appear on a milk carton. The anniversary of his disappearance became National Missing Children's Day.
Hernandez was arrested in 2012 after police got a tip. The 53-year-old Maple Shade, N.J., resident gave authorities a confession, but his defense argues it was false and prompted by mental illness.
