U.S. District Judge Benjamin H. Settle on Friday also gave Edgar Hugh Kelly, 37, three years of supervised community service time and ordered him to pay restitution.
Kelly worked for nearly 13 years as a teller and office manager for the small credit union, which serves employees of Simpson Construction.
The embezzlement came to light in 2010 after an internal audit found Kelly had submitted false records to hide a loss of funds in the credit unions accounts with other banks.
He was fired and pleaded guilty in November to theft from a lending, credit or insurance institution.
Federal prosecutors said Kelly used an elaborate scheme to steal money for several years, including strategically timed fund transfers and altered financial documents.