Social Security Disability Insurance (SSDI, sometimes also abbreviated as SSD) is a Social Security program that pays monthly benefits to you if you become disabled before you reach retirement age and aren't able to work.

Eligibility for Social Security Disability

To qualify for the SSDI program, you must have worked a certain number of years in a job where you paid Social Security taxes (FICA) taxes. Specifically, you need to have earned a certain number of work credits; you can earn up to four work credits per year. If you haven't worked long enough when you become disabled, and have low income and assets, you can apply for Supplemental Security Income (SSI) instead.

Work Credits

How many work credits you need to qualify for SSDI benefits depends on how old you were when you became disabled. For example, if you are 50 years old when you become disabled, you need 28 work credits, or to have worked for seven years (and at least five of those years must have been within the last 10 years).

Medical Eligibility

You also must have a medical condition that meets the SSA’s definition of disability. SSDI benefits are eligible only to those with a severe, long-term, total disability.

Severe means that your condition must interfere with basic work-related activities.

Long-term means that your condition has lasted or is expected to last at least one year.

Total disability means that you aren't able to perform "substantial gainful activity" (SGA) for at least one year. If you are currently working and make over a certain amount ($1,130 per month in 2016 for disabled applicants, $1,820 for blind applicants), the SSA will find that you're performing SGA and that you are not disabled enough to qualify for SSDI benefits.

Approval for Disability Benefits

If you are approved for disability benefits, you won't receive SSDI benefits until you have been disabled for five complete months. If you are approved right away (for instance, because you just had a liver transplant), you would have to wait five months for your checks to start.

However, it's more likely you wouldn't be approved for about six months to a year (after at least one level of appeal). In that case, when you finally get approved, you would be paid disability backpay starting with the sixth month after your disability began (your disability onset date).

After you are paid any backpay owing, you would get a disability benefit check each month. If your household income is over a certain amount, you will have to pay taxes on your disability benefits.

Your family members may also be eligible for a partial monthly benefit.

Denial of Disability Benefits

If your application for SSD is denied (most initial applications are), you can appeal the decision. You have to request a review of the denial within 60 days of when you receive the denial letter. The first step of the appeal process in most states is the Request for Reconsideration, a review of your file by another claims examiner. If you are denied again, you can appeal to the next stage, by requesting a hearing with an administrative law judge who works for the SSA.