Many disability claimants wonder what they ultimately need to prove in order to win their disability case.  For many claimants, especially those that may have had simple type sedentary (primarily sitting) work they will need to show that they cannot continue to do this type work.  On the other hand, if you are applying as a person that has done primarily heavier type work in the past such as construction, similar repair type work, or any other job that required some heavier lifting or being on your feet most of the day this will not be one of the things that you will have to worry about as much.  Two important things that must be considered are whether the past work were done at the substantial gainful level within the previous 15 years.  What this means is that under the Social Security rules the administration set a minimum monthly threshold in terms of earnings that would be considered the substantial gainful level.  However, even if you met this monthly minimum threshold you would be able to argue that if you only did the job for 6 months or less that it was only trial work and therefore should not count as relevant past work.  However, even if the work was only done part time they still may count it if substantial income was earned.  Also, sometimes relevant, is the fact that if you can do a past job that no longer exists in the national economy than this will also defeat a successful disability claim.

Was Past Work Accurately Described?

Sometimes a claimant will have a past job that was performed in a way that is different than the official job description in the dictionary of occupational titles, and may have been more difficult to perform than the way it is ordinarily done.  Unfortunately, Social Security will look at how the job is ordinarily done and not how it was actually done by the claimant in this situation.  SSR 82-61. In addition, if you did the work based on special accommodations (and not based on how its ordinarily done) you still need to show that you cannot do the work even with these special accommodations.
If you have a hearing with an administrative law judge it is also very important that the vocational expert describe the job title that best describes the job that was actually done in the past.  Even if a DOT job title appears similar to the one previously done it makes sense to have the expert to describe the duties of the job to determine if they closely match what you did in past work.  If they do not match another more closely related job title should be found by the expert so that past work is properly characterized.  This is important because some jobs like an office helper may be considered sedentary but if you performed office type work that often involved doing heavier type work then the expert would need to take that into account.
Normally, this step of the disability determination process (step four) can be a problem if the type of work done was relatively simple and didn’t involve great physical abilities, and so keep this in mind if you engaged in work that may be described as this sort.  You will need to provide social security with the details of your past work they describe the process here.