Even though full retirement age is between 65 and 67, benefits can start being collected at age 62. If a person was born after 1937, full retirement age ranges between 65 and 67 years old; for those born before 1937, full retirement age is always 65.
For people born between 1937 and 1960, full retirement age increases from 65 and two months for those born in 1938 up to 66 and 10 months for those born in 1959. For those who decide to take their benefits early, which can be done anytime between the ages of 62 and 67, monthly benefits for those payments will be reduced. The payments are reduced because the person will still receive benefits for the full duration of their life, so because they are collected early, they are reduced at a percentage rate that depend on exactly how early they are taken to try to ensure the same amount is paid out in total.
On average, for people who were born after 1960, collecting retirement payments as early as possible at age 62 means that monthly payments will be reduced by about 30 percent. Taking benefits at age 63 will be reduce payments by about 25 percent, at 64 will reduce them by about 20 percent, at 65 by about 13.3 percent, and at 66 by only about 6.7 percent. Retirement payments can also be delayed; if this is done, it is possible to receive delayed retirement credits that increase the monthly benefit.