If you were born before 1938, you were eligible for your full Social Security benefit on your 65th birthday. Starting in 2003, the age at which full benefits are payable began to increase gradually. Although the full retirement age is rising, you should still apply for Medicare benefits within three months of your 65th birthday. If you wait longer, your Medicare medical insurance, Part B, and prescription drug coverage, Part D, may cost you more money.

Year of birth - - Full retirement age
1937 or earlier - - 65
1938 - - 65 and 2 months
1939 - - 65 and 4 months
1940 - - 65 and 6 months
1941 - - 65 and 8 months
1942 - - 65 and 10 months
1943-1954 - - 66
1955 - - 66 and 2 months
1956 - - 66 and 4 months
1957 - - 66 and 6 months
1958 - - 66 and 8 months
1959 - - 66 and 10 months
1960 or later - - 67