The core requirement: you must have a medical condition that stops you from working

Social Security approves SSDI for adults when two things are both true. First, you have a medical condition—physical, mental, or both—that is severe enough that it prevents you from doing substantial work. Second, your condition is expected to last at least 12 months or result in death. That is the medical part of the decision.

The work part is separate. You also need enough work credits from jobs where you paid Social Security taxes. For adults, you typically need 40 credits total, with at least 20 of them earned in the 10 years before you became unable to work. If you became disabled before age 31, the rules are different and usually easier to meet. The exact number depends on your age when your disability began.

Social Security does not care why you cannot work—whether it is an injury, illness, mental health condition, or a combination. It also does not matter whether you have tried to work and failed, or whether you have never worked since becoming disabled. What matters is whether a medical professional has documented that your condition prevents substantial work.

Key Takeaways

  • Your condition must be severe enough to prevent substantial work and expected to last at least 12 months or result in death.
  • Adults typically need 40 work credits, with at least 20 earned in the 10 years before disability began.
  • Social Security uses its own list of conditions (the Blue Book) as a starting point, but will also consider conditions not on the list if medical evidence shows they prevent work.
  • You must provide medical records, test results, and documentation from doctors or other treatment providers to prove your condition.
  • The decision is based on what you can do, not on a diagnosis alone—two people with the same condition may have different outcomes.

What "substantial work" means in Social Security's terms

Social Security defines substantial work as earning more than a set monthly amount. For 2024, that amount is $1,550 per month (the figure changes each year). If you are earning more than that, Social Security will usually deny your claim, even if you say the work is difficult or painful.

Below that amount, Social Security looks at whether you are doing work that is significant in nature and duration. This means they consider not just the money, but whether you are actually performing job duties, showing up regularly, and contributing meaningfully. Self-employment counts the same way as a regular job.

If you are not working at all, Social Security assumes you cannot work substantially. But they will still need medical evidence of why. Sitting at home without income is not, by itself, proof of disability.

How Social Security evaluates your medical condition

Social Security has a reference guide called the Blue Book, which lists conditions they recognize as disabling. It includes categories like cancer, heart disease, arthritis, depression, anxiety disorders, intellectual disability, and many others. If your condition matches one of these listings and your medical records meet the specific criteria, approval can be faster.

But your condition does not have to be on the Blue Book list. Social Security will also consider conditions not listed if your medical records show that the combination of your symptoms, limitations, and treatment effects prevents you from working. For example, a rare condition or an unusual combination of common conditions can still may have access to.

What matters most is the medical evidence itself: test results, imaging, lab work, treatment records, and statements from your doctors about what you can and cannot do physically and mentally. Social Security will request these records directly from your healthcare providers. If you have not seen a doctor in a long time, or if your records are incomplete, approval becomes much harder.

Functional limitations: what you can and cannot do

Social Security does not make a decision based on your diagnosis alone. Instead, they assess your functional limitations—the actual things your body or mind cannot do because of your condition. A person with arthritis might have full mental capacity but be unable to stand for more than 30 minutes. A person with depression might be able to perform physical tasks but unable to concentrate or follow instructions.

The agency looks at whether you can do basic work activities: sitting, standing, walking, lifting, carrying, understanding instructions, remembering tasks, getting along with others, and managing stress. They also consider whether your condition causes pain, fatigue, or other symptoms that would interfere with work even if you could physically perform the job.

Your doctor's statement about your limitations carries significant weight. If your treatment provider writes that you cannot sit for more than two hours at a time, or that you have severe memory problems, or that you cannot tolerate being around other people, Social Security uses that information to decide whether you can do any job that exists in the economy.

Age matters: the rules are easier if you became disabled before 31

If you became unable to work before age 31, you need fewer work credits. The exact number depends on your age when disability began, but it can be as low as 6 credits earned in the 3 years before you became disabled. This rule exists because younger people have had less time to build up a work history.

If you became disabled between ages 31 and 42, you need 20 credits earned in the 10 years before disability. At age 42 and older, you need the full 40 credits with 20 in the last 10 years. These thresholds are set by law and do not change based on your individual situation.

What Social Security will ask you to prove

When you explore, Social Security will ask for medical records from every doctor, hospital, clinic, or mental health provider you have seen since your condition began. They will also ask about your work history, your education, and what you did in previous jobs. They want to know whether you have any skills that might allow you to do different work, even if you cannot do your old job.

You will need to describe your typical day: how long you can sit, stand, or walk; whether you have pain or other symptoms; how your condition affects your ability to concentrate, remember things, or get along with others; and whether you take medications that cause side effects affecting your ability to work.

If you do not have recent medical records, Social Security may send you to a doctor they choose and pay for the examination. This is called a Consultative Examination. The results become part of your file, though they are not the only evidence Social Security considers.

Mental health conditions and SSDI

Mental health conditions—depression, anxiety, bipolar disorder, schizophrenia, PTSD, and others—can may have access to for SSDI if they are severe enough to prevent work. Social Security evaluates these the same way as physical conditions: by looking at your medical records, your treatment history, and your functional limitations.

For mental health conditions, Social Security looks at whether you can concentrate, understand and follow instructions, get along with coworkers and supervisors, and handle the stress of a job. They also consider whether your condition causes you to miss work frequently, or whether medication side effects interfere with your ability to function.

You will need records from a mental health provider—a psychiatrist, psychologist, clinical social worker, or counselor—showing your diagnosis, how long you have been in treatment, what medications you take, and how your condition affects your daily functioning. If you have been hospitalized or received crisis care, those records are important too.

Frequently Asked Questions

Can I get SSDI if I have never worked?

No. You must have work credits from jobs where you paid Social Security taxes. If you have never worked, you may be able to receive Supplemental Security Income (SSI) instead, which has different rules and does not require work credits. SSI is based on financial need rather than work history.

What if my condition is getting better?

If your condition is improving, Social Security may deny your claim or approve it for a shorter period before a medical review. They need to see evidence that your condition is expected to last at least 12 months. If you are recovering, your medical records should show that, and Social Security will factor it into their decision.

Does Social Security consider my age when deciding if I am disabled?

Yes, but only in specific ways. If you are 55 or older and cannot do your past work, Social Security may find you disabled even if they think you could do other work—this is called the "grid rules." Age also affects how many work credits you need. But age alone does not make you disabled.

What happens if I disagree with Social Security's decision?

You can request a reconsideration, which means a different Social Security employee reviews your file. If you disagree again, you can request a hearing before an administrative law judge. You can also submit new medical evidence at any stage. Many people are denied initially but approved after a hearing.

Can I work part-time and still get SSDI?

Yes, if you earn less than the substantial work amount ($1,550 per month in 2024). SSDI also includes a trial work period where you can test your ability to work without losing benefits. After that, there are other work incentives that let you keep some benefits while earning income, depending on how much you earn.