When you file an application for any of the following types of Social Security benefits:

• Retirement benefits,
• Spousal benefits,
• Widow(er) benefits,
• Child benefits,
• Mother/father benefits, or
• Dependent parent benefits…

…you have the option of backdating your application by up to 6 months. That is, you can file retroactively, thereby getting a lump sum for those 6 months of benefits and having your benefit calculating going forward as if you had filed 6 months earlier.

Example: You file for your retirement benefit at age 68 and 10 months. You ask for the maximum retroactivity. Result: your monthly benefit will be what it had been if you had filed for it to begin at age 68 and 4 months, and you will receive a lump sum for 6 months of benefits.

Two Important Exceptions

Exception #1: You cannot backdate an application for retirement, spousal, or widow(er) benefits to a month earlier than your full retirement age. For example, if you reach your full retirement age in February of a given year and you file for retirement benefits in April of that year, you can only backdate your application back to February.

Exception #2: If you are filing for a) disability benefits or b) spousal/widow(er)/child benefits based on the work record of somebody who is currently entitled to Social Security disability benefits, you can backdate your application by up to 12 months rather than the normal 6 months. (If it is an application for spousal benefits though, it will still be limited by exception #1 above.)

Avoiding Accidental Retroactive Applications

When you file a Social Security application online, the application asks when you want your benefits to start. Similarly, if you file by phone or in person, the SSA employee with whom you speak is supposed to ask when you want your benefits to start. But there have been cases in which the SSA employee doesn’t ask. Instead, they just start the applicant’s benefit immediately, with the maximum possible retroactivity (i.e., seeking to give the applicant the largest immediate lump sum possible). And, in some cases, that’s not what the applicant actually wanted.

So it’s always important to be clear about exactly when you want your benefit to begin (e.g., “I want my benefit to begin effective October 20xx, at age 69 and 7 months”).

But Didn’t the Rules Change?

Contrary to a common misconception, the Bipartisan Budget Act of 2015 (i.e., the law that made a bunch of changes to Social Security several years ago) did not change any of the above rules.

With regard to retroactive benefits, what that law eliminated was the ability to retroactively unsuspend benefits. (You used to be able to file at full retirement age, immediately have your benefits suspended, then at a later date choose to retroactively unsuspend — thereby getting a lump sum for all the months you would have received if you hadn’t suspended. But this retroactive unsuspension is no longer an option.)