1. What Is SSDI?

SSDI is designed for people who have worked long enough and paid Social Security taxes but are now unable to work due to a medically determinable physical or mental impairment expected to last at least 12 months or result in death. It is different from Supplemental Security Income (SSI), which is based on financial need rather than work history.

2. The Two Main SSDI Eligibility Requirements

A. Work Credit Requirements

You must have earned enough work credits through jobs covered by Social Security:

• You earn one work credit for each $1,730 of wages or self-employment income in 2025, up to four credits per year
• Generally, you need 40 credits total, with 20 earned in the last 10 years ending the year you became disabled
• Younger applicants may qualify with fewer credits:
• Under age 24: 6 credits earned in the 3 years before disability onset
• Age 24 to 31: Credits for working half the time between age 21 and when disability began
• Age 31 and older: Usually 20 credits in the last 10 years

Your specific requirement depends on your age when you became disabled.

B. Medical Disability Requirements

SSA defines disability strictly. To be eligible:

• You must have a severe medical impairment that significantly limits your ability to do basic work-related activities
• Your condition must be expected to last at least 12 months or result in death
• You must be unable to perform past relevant work or adjust to any other type of substantial gainful work based on your age, education, and experience

3. What Is Substantial Gainful Activity (SGA)?

SSA uses SGA levels to determine disability eligibility:

• In 2025, if you earn more than $1,550 per month (or $2,590 if blind), SSA generally considers you able to engage in substantial gainful activity and therefore not disabled
• Earnings below these thresholds do not automatically qualify you, but they satisfy the income part of eligibility while medical reviews determine your disability status

4. Does Your Condition Meet SSA’s Listing of Impairments?

The SSA maintains a Listing of Impairments (“Blue Book”), which includes conditions that are considered severe enough to prevent working. Some examples include:

• Musculoskeletal disorders (e.g. severe back injuries)
• Cardiovascular conditions (e.g. chronic heart failure)
• Neurological disorders (e.g. multiple sclerosis, epilepsy)
• Mental health disorders (e.g. schizophrenia, bipolar disorder)

If your condition is not listed, you may still qualify if your limitations prevent you from performing substantial work.

5. The Five-Step Evaluation Process

SSA uses a five-step process to assess eligibility:

1. Are you working above SGA levels? If yes, not disabled.
2. Is your condition severe? It must significantly limit work activities.
3. Does your condition meet or equal a listed impairment?
4. Can you do any past relevant work? If yes, not disabled.
5. Can you adjust to other work? SSA considers age, education, and skills to decide.

Meeting each step with strong medical evidence is crucial for approval.

6. How to Strengthen Your SSDI Eligibility Case

• Seek consistent medical treatment and follow all prescribed therapies
• Ensure your doctors provide detailed records and opinions outlining how your condition limits your work abilities
• Keep track of symptoms and daily limitations in personal journals or logs
• Review your work history and credits before applying to confirm your technical eligibility