What constitutes disability? For Social Security disability or SSI purposes, to be considered disabled, individuals must have an impairment, either medical, psychological, or psychiatric in nature, that keeps them from being able to do a substantial amount of work. In addition, a person's impairment must have prevented the individual from doing a substantial amount of work for at least 12 months, or be expected to prevent work for at least 12 months. (This durational requirement means that while severe back conditions can qualify for Social Security disability or SSI, wrist or ankle sprains or broken bones seldom qualify as disabling conditions.)
To be considered a disabled person for Social Security purposes, a disability applicant must be unable to perform substantial work. Generally, this means working and earning above a certain amount; in 2019, this means making over $1,220 per month. This is called the "substantial gainful activity" (SGA) threshold. But for the self-employed (people who own businesses or do contract work), there are other tests Social Security uses to determine if someone is doing SGA. (For more information on working and what Social Security considers substantial gainful activity, see our section on SGA, work, and disability.)
Applicants cannot be working above the SGA level when they apply for benefits (some applicants keep working while they await a decision, planning to quit if they qualify for benefits). A person earning more than the SGA amount who applies for Social Security disability or SSI benefits will be denied the same day without having their impairments or medical records even considered. (This is referred to as a "technical denial.") However, disabled individuals may be working part-time when they apply for Social Security disability, as long as they don't earn more than the SGA amount (assuming the amount of work they do doesn't lead Social Security to think they could work a full-time job).
To qualify for disability benefits, a disability applicant's medical records must contain evidence of the physical or mental impairment and exactly how it prevents the applicant from working (their "functional limitations"). The evidence must be up to date (for example, the records must include doctors' notes or lab tests from the last 60 to 90 days).
Unless Social Security can tell from your medical records that your medical condition is so severe that it meets the requirements of a Social Security impairment listing (which means automatic approval for benefits), Social Security will assess what type of work you are capable of.
For a physical impairment, Social Security will decide whether an applicant can do medium, light, or sedentary work by looking at the functional limitations in the applicant's medical records (such as "unable to walk for more than 2 hours" or "restricted from lifting more than 20 pounds").
For psychological, psychiatric, or cognitive impairments, Social Security will assess whether the person can understand and remember instructions, maintain attention and concentration, interact appropriately with others, and respond appropriately to changes or hazards in the workplace. After this assessment (called a residual functional capacity, or RFC, assessment), Social Security will decide whether the person can do semi-skilled work, unskilled work, or less than unskilled work.
Next, Social Security uses the RFC assessment to decide whether the disability applicant can work doing their past job (full-time). Most of the time, Social Security agrees that disability applicants cannot do their past jobs (the work often has medium to heavy physical demands).
If Social Security agrees the applicant cannot return to his or previous work, the agency will decide if the applicant's RFC allows him or her to do different work. As part of this determination, Social Security is required to use a set of rules, called the medical-vocational grid, to determine if there are other jobs that the applicant can still do (or be expected to learn to do). The grid rules, however, are usually only helpful for older applicants. For example, a 45-year old car mechanic might be expected to switch to doing auto body repair if the job duties are similar enough, if the other work is more tolerable physically. But if an applicant is older and has little education or transferable job skills, the grid rules may not expect the person to learn a new job, and will consider the person disabled.
For information on what medical conditions are considered disabilities under both the listings and when considering RFCs, see our section on disabling medical conditions and impairments.