Full retirement age (FRA) is the age when a person may be entitled to 100% of their Social Security benefits. It depends on the year of birth. If you were born between 1943 and 1954, full retirement age is 66. If you were born in 1955, FRA is 66 and 2 months. For those born between 1956 and 1959, it increases by two months each year, and for those born in 1960 or later, it is 67.