At step 4 of Social Security's sequential evalution process, the SSA considers your ability to perform your past relevant work. This is a very important step in the process, because if the SSA determines that you retain the residual functional capacity to return to your past relevant work, your disability claim will be denied.
For those applying for disability benefits, it is important to fully describe the requirements of your past jobs in your work history report. Don't forget to specify the lifting, standing and other requirements of your prior work.
Social Security will match your current abilities to the requirements of your past work. The SSA looks at both the way you described your past work, and how those jobs are generally performed in the national economy. Social Security will simply compare your abilities with the requirements of each of the previous jobs. It doesn't matter if the past job doesn't exist anymore.
Not all your past work is past relevant work.
You may have learned job skills at your previous work. Social Security classifies jobs according to skill level. If your acquired job skills can transfer to skilled or semi-skilled work that you are still able to do, it can be problematic for your claim.
Eliminating your past relevant work is important for all claimants, but particulary for Social Security disability claimants over the age of 50.