Full retirement age

Full retirement age (also called "normal retirement age") had been 65 for many years. However, beginning with people born in 1938 or later, that age gradually increases until it reaches 67 for people born after 1959.

Note you can still retire at age 62 -- but with reduced benefits.

See this page for an "full retirement age calculator".
http://www.ssa.gov/pubs/ageincrease.htm