So from the five step process we know we need to prove you cannot do other work, not just the work you have done before. There are a few rules we can use to help us rule out other work though, one of them being POMS § 416.962 Medical-vocational profiles showing an inability to make an adjustment to other work.
This rule is twofold, the first section states if you no more than a marginal education, meaning a 6th grade education or less, and 35 years of more of work experience during which you did only arduous unskilled physical labor and are no longer able to do this kind of work due to severe impairments, Social Security Administration will consider you unable to do lighter work and therefore disabled.
The second section pertains to individuals of at least 55 years of age, with no more than a limited education, and have no past work experience, if you have a severe medically determinable impairment, the Social Security Administration will find you disabled. This means if you are 55 or older, did not finish high school, and have not worked at SGA levels in the last 15 years, so long as you have a severe medically determinable impairment, you are disabled.
Another way in which we can rule out other work for individuals of certain ages is through what are known as the Medical Vocational Guidelines, or Grid Rules