What Is SSDI Back Pay?

SSDI back pay is the money the Social Security Administration (SSA) owes you for the period when you were disabled but had not yet started receiving monthly benefits.

Because SSDI applications often take several months — or even over a year — to process, back pay ensures you’re compensated for the time you were eligible but waiting for approval.

For example, if you applied for SSDI in January 2023 and were approved in July 2024, your back pay would typically include payments for the months you were eligible during that time (minus the required waiting period).

How Back Pay Is Calculated

The amount of SSDI back pay you can receive in Massachusetts depends on three key dates:

1. The Date You Applied for SSDI

This is the date the SSA officially received your application. You can usually receive back pay starting from your application date or up to 12 months before that date if you were already disabled during that time.

2. The Established Onset Date (EOD)

The EOD is the date the SSA determines your disability began. It may be the same as the date you claimed on your application, or it may be changed based on medical evidence.

The earlier your onset date, the more back pay you could be entitled to — as long as it’s supported by your medical records.

3. The Five-Month Waiting Period

By law, SSDI includes a five-month waiting period after your onset date before you can start receiving payments. This means your back pay will not include the first five months after you became disabled.

For example:
If your disability began in January 2023, your benefits would start in June 2023 (after the five-month waiting period). If your application wasn’t approved until June 2024, you’d likely receive back pay for 12 months of missed payments.

How Far Back Can SSDI Back Pay Go?

The SSA allows up to 12 months of retroactive pay before your application date, but only if you can prove that your disability started earlier than when you applied.

That means you could receive:

• Up to one year of retroactive benefits (for the period before your application date), plus
• All the months between your application date and your approval date, minus the five-month waiting period.

This can add up to a significant amount, especially if your case took a long time to process.

How SSDI Back Pay Is Paid

In Massachusetts, SSDI back pay is usually paid in one lump sum, deposited directly into your bank account once your claim is approved.

If you also qualify for Supplemental Security Income (SSI), your SSI back pay may be handled differently — it’s often split into three smaller payments over six-month intervals to prevent financial hardship.

If you worked with a lawyer or advocate, attorney’s fees (typically capped at 25% of your back pay or $7,200, whichever is lower) will be automatically deducted from your lump-sum payment by the SSA before you receive it.

Massachusetts-Specific Factors

While SSDI is a federal program, Massachusetts residents may experience slightly different processing times due to local SSA office workloads and regional hearing schedules. This can impact how long it takes to receive your back pay.

Massachusetts also offers state assistance programs for residents waiting for SSDI approval, which can help bridge the financial gap. Once SSDI is approved, some of these programs may require you to reimburse part of the state aid from your back pay.

Example of an SSDI Back Pay Calculation

Let’s break down a sample timeline:

• Disability Onset Date: January 2023
• Application Date: June 2023
• Approval Date: July 2024

Here’s how the SSA calculates:

1. The five-month waiting period covers February to June 2023.
2. Your benefit eligibility begins in July 2023.
3. Your case is approved in July 2024, so you are owed 12 months of back pay (July 2023 to June 2024).

If your monthly benefit amount is $1,400, your back pay would be $16,800 — paid as a lump sum after approval.