How do I prove my disability case at step four? What is past relevant work?

When you’re applying for Social Security disability, if your impairments do not meet or equal a listing at step three of the five-step sequential analysis, the Social Security Administration (SSA) will determine your residual functional capacity (RFC). RFC is a function-by-function assessment of the most a claimant can functionally do on a regular and continuing basis, which equates to a forty-hour work week.

Using the RFC, the SSA will then move onto step four. Step four asks whether the claimant can return to any past relevant work.

Past relevant work is any job or occupation that the claimant performed at the substantial gainful activity (SGA) level for long enough to learn how to do the job. How long a job takes to learn depends on the job’s skill level. There are three basic skill levels for jobs: unskilled, semi-skilled, and skilled. The more skilled a job is, the longer it takes to learn, and the longer a person will need to hold the job for it to qualify as past relevant work.

If a claimant has had an unskilled job at the SGA level for three or more months, it will usually qualify as past relevant work because that’s about how long it takes to learn unskilled jobs.

On the other hand, if a claimant had a semi-skilled or skilled job for only three months, it would probably not qualify as past relevant work because the claimant did not hold the job long enough to learn how to do it.

To determine whether a claimant’s RFC allows the claimant to return to any past relevant work, the SSA compares the job demands of the past relevant work with the limitations in the RFC. For example, if a claimant can only concentrate for brief periods of time, skilled and semi-skilled work would usually be precluded. On the other hand, if a claimant is limited to lifting only ten pounds at a time, any work above the sedentary exertional level would be precluded.

Determining whether a claimant’s past job or occupation is past relevant work can make the difference between winning and losing a case.

If the claimant can return to any past relevant work, then the claimant is found to be not disabled, and the five-step analysis ends. If a claimant cannot return to any past relevant work, then the SSA moves to step five, the last and final step.

If you have a severe physical or mental illness or injury, you should consult with an attorney experienced in Social Security disability for help and advice proving your case.