Office of the Chief Actuary. Retirement before Normal Retirement Age (NRA) reduces benefits, and retirement after NRA increases benefits. NRA, also referred to as Full Retirement Age, varies from age 65 to age 67 by year of birth.ffice of the Chief Actuary. Retirement before Normal Retirement Age (NRA) reduces benefits, and retirement after NRA increases benefits. NRA, also referred to as Full Retirement Age, varies from age 65 to age 67 by year of birth.