Can I collect Social Security retirement benefits retroactively?

Yes, if you are over full retirement age (FRA), the age at which you qualify for 100 percent of the benefit calculated from your lifetime earnings. Social Security does not allow what it calls “retroactivity” if you claim benefits before then.

If you claim retirement benefits upon reaching FRA  — which is 66 and 10 months for people born in 1966 and 67 for those born in 1960 and later — Social Security will pay them starting that month. If you apply one to five months after you reach FRA, you can get retroactive benefits in a lump sum for that number of months. If you file six months or more past full retirement age, you can get up to six months in back benefits.

For example, if you claim benefits four months after you reach FRA, you can get payments for those four months. If you wait until a year after you hit full retirement age, you can get six months of retroactive payments, but not a full year.

Retirees who claimed benefits after FRA and then suspended them used to be able to collect retroactive payments for the entire period during which their benefits were suspended, but Congress ended that option in April 2016. There is now no retroactivity for benefits that were suspended.

Keep in mind

Collecting retroactive benefits gets you an immediate lump sum but carries a future cost: You will lose the delayed retirement credits you earned, which will permanently reduce your payment by two-thirds of 1 percent for each back-paid month, or a total of 4 percent for a six-month retroactive payment.