Social Security Disability Insurance (SSDI) offers benefits for covered employees who become unable to work due to a serious medical condition. When you work, a portion of the taxes that are deducted from your paycheck goes toward funding the SSDI program.
As long as you work and pay Federal Insurance Contributions Act (FICA) taxes, you're covered under SSDI. Think of a private insurance provider—if you stop paying the premiums for your car insurance, your coverage will expire at the end of the month. Then, if you get into a car accident the following month, you won't be able to make an insurance claim.
SSDI works in a similar way, but with a longer grace period where you can maintain insurance without paying your "premium"—in this case, your payroll taxes. If you stop working and can't return to work, your coverage will eventually expire. The date you stop being covered is called the date last insured (DLI). You might think of the DLI as the expiration date for SSDI benefits.
When you file an application for disability benefits, Social Security will calculate your DLI by reviewing your earnings history for the ten years prior to your filing date (the "look back period"). The agency is looking to see that you've paid your "insurance premiums" by working at least five out of those past ten years.
Specifically, Social Security uses a system of work credits to determine eligibility for SSDI. In 2023, for every $1,640 you earn, you get one credit. You can have up to 4 credits per year. To qualify for SSDI, you'll need to have 20 work credits over the past ten years. (The rules are a bit different if you're under 30. For more information, see our article on SSDI work credits.)
Your "date last insured" is the last date you're eligible to qualify for SSDI. You'll need to establish that you became disabled before your DLI in order to receive monthly SSDI benefits. Generally speaking, your DLI will be about five years after you last worked.
In theory, you don't have a time limit on when you can file for SSDI benefits, so long as you have medical records dating back before your DLI that support a finding that you're disabled. But in practice, the longer you wait to file for SSDI, the more likely your date last insured will pass without a disability determination (in Social Security lingo, your DLI becomes remote.)
Having a remote DLI limits your options because the agency doesn't usually look at any medical treatment you've received after your DLI. So if you have a nerve conduction study in 2022 showing carpal tunnel syndrome but your DLI is in 2019, Social Security isn't likely to use the 2022 test to find that you qualified for SSDI in 2019.
In order to qualify for SSDI after your DLI has passed, you'll need to show that your onset date of disability was before your DLI. (You can also qualify if you have a protective filing date that's before your DLI.) Your onset date is the "when" you became disabled, and it must have some medical significance—such as the date of your first recorded examination, a visit to your doctor, or when you stopped working because of your condition.
Depending on how far back your DLI is, getting the medical evidence necessary to show that your disability onset was before your DLI can be a challenge. If your DLI was within the past year, you shouldn't have too much of a problem, but if your DLI was several years ago, you'll have a harder time.
Make sure that you let the agency know about any and all medical providers you saw prior to your DLI. Even if you have a gap in treatment, you might be able to convince Social Security to approve your claim based on an earlier medical record that falls within your SSDI coverage period.
If you only started receiving medical treatment after your DLI, the agency can sometimes agree that you have an earlier onset date. For example, if your DLI is September 30, 2020, and you saw a rheumatologist on October 15, 2020, who diagnosed you with severe arthritis, Social Security will likely infer that you were disabled before your DLI (because it's reasonable to assume that the arthritis existed two weeks before your diagnosis.)
Yes, you can have more than one DLI. This is most common in situations where a disability applicant has an inconsistent work history with periods where they might not earn enough to be covered under SSDI.
If you can't qualify for benefits under the SSDI program because you can't establish that your disability onset date was before your DLI, you might still be eligible for Supplemental Security Income (SSI) benefits. SSI isn't based on your work history, so it doesn't have a date last insured, but you do need to have below a certain amount in assets and income to qualify.
For more information, see our overview of SSI.
Updated November 10, 2022