Social Security Disability Insurance (SSDI) provides monthly financial support to individuals who can no longer work due to a qualifying disability. While the program offers crucial relief, eligibility rules can be complex, and many initial applications are denied due to incomplete documentation or misunderstood criteria.
This guide explains how SSDI eligibility works, what the key medical and work requirements are, and how to navigate the application process with the best chance of approval.
What Is SSDI?
SSDI is a federal program managed by the Social Security Administration (SSA) that pays benefits to workers who’ve earned enough work credits and are now unable to maintain gainful employment due to a physical or mental disability expected to last at least one year—or result in death.
It’s different from Supplemental Security Income (SSI), which is needs-based and not tied to work history.
Who Is Eligible for SSDI?
Eligibility for SSDI is based on two main criteria:
1. Work Credits
You must have worked long enough—and recently enough—under Social Security:
Most people need at least 40 work credits (10 years of work), 20 of which must have been earned in the last 10 years.
Younger workers may qualify with fewer credits depending on their age at the time of disability.
2. Qualifying Disability
You must have a medically determinable impairment that prevents you from working in any capacity and is expected to last at least 12 months or result in death.
SSA maintains a Listing of Impairments, which includes conditions such as:
Musculoskeletal disorders (e.g., back injuries)
Neurological disorders (e.g., epilepsy, multiple sclerosis)
Mental disorders (e.g., depression, PTSD, schizophrenia)
Cardiovascular conditions
Respiratory illnesses
Cancer (certain types and stages)
If your condition isn’t listed, you can still qualify if it is severe and well-documented.
SSDI vs SSI:Key Differences
| Feature | SSDI | SSI |
|---|---|---|
| Based on Work History | ✅ Yes | ❌ No |
| Income Limits | No, but work earnings affect status | ✅ Yes, strict income/resource rules |
| Health Insurance | Medicare after 24 months | Medicaid (immediately, in most states) |
| Benefit Amount | Based on your lifetime earnings | Fixed national amount (varies by state) |
Some individuals may qualify for both SSDI and SSI, depending on their work and financial situation.
How to Apply for SSDI
You can apply:
Online at SSA.gov
By calling the Social Security Administration
In-person at your local Social Security office (appointment recommended)
You'll need:
Medical records
Work history
Contact information for healthcare providers
Details of your condition and how it limits your ability to work
Processing times vary, and many applicants receive a decision within 3–6 months.
What If Your SSDI Claim Is Denied?
More than 60% of initial SSDI claims are denied. Common reasons include:
Insufficient medical evidence
Missing documentation
Condition not considered severe enough
Incomplete work history
You can file an appeal, which includes:
Request for reconsideration
Administrative Law Judge (ALJ) hearing
Appeals Council review
Federal court review (in rare cases)
Having legal representation or working with a disability advocate can significantly improve your chances of approval during appeals.
How Much Does SSDI Pay?
Monthly benefits vary depending on your prior earnings. In 2025, the average SSDI payment is around $1,537/month, but payments can be higher or lower depending on your work history. After two years on SSDI, recipients are eligible for Medicare.
Final Thoughts
If you’re unable to work due to a medical condition, SSDI may offer essential financial support—but the application process requires careful documentation and a clear understanding of eligibility rules.
Start by reviewing your medical records, checking your work credits at SSA.gov, and speaking with a qualified representative if needed. Whether you’re filing for the first time or appealing a denial, knowing how SSDI eligibility works can make all the difference.