Arthur Jones, 73, who is out on $20,000 bail, was originally charged with four felony counts of false identity, identity theft and fraud but pleaded guilty to a single charge of applying for a driver's license or identity card under a false name, the Las Vegas Sun reported Monday.
Prosecutors said Jones disappeared from his Chicago-area home in 1979 and had moved to the Las Vegas area and assumed a new identity.
He was declared legally deceased in 1986, and his wife and children collected Social Security benefits as a result.
The reason for his disappearance was unclear but authorities in Chicago said he might have been escaping gambling debts and possible organized crime affiliations, the Sun reported.
He had been in hiding for 32 years as a casino worker in Las Vegas after assuming a new identity, authorities said.
Under a plea agreement Jones will make restitution to the Social Security Administration and could end up paying between $46,000 and $75,000 for Social Security fraud, his attorney said.