20 C.F.R. § 416.965

(a) General. Work experience means skills and abilities you have acquired through work you have done which show the type of work you may be expected to do. Work you have already been able to do shows the kind of work that you may be expected to do. We consider that your work experience applies when it was done within the last five years, lasted long enough for you to learn to do it, and was substantial gainful activity. We do not usually consider that work you did more than five years before the time we are deciding whether you are disabled applies. A gradual change occurs in most jobs so that after five years it is no longer realistic to expect that skills and abilities acquired in a job done then continue to apply. If you have no work experience or you did work that started and stopped in a period of fewer than 30 calendar days (see § 416.960(b)(1)(ii)) during the five-year period, we generally consider that these do not apply. If you have acquired skills through your past work, we consider you to have these work skills unless you cannot use them in other skilled or semi-skilled work that you can now do. If you cannot use your skills in other skilled or semi-skilled work, we will consider your work background the same as unskilled. However, even if you have no work experience, we may consider that you are able to do unskilled work because it requires little or no judgment and can be learned in a short period of time.

(b) Information about your work. Under certain circumstances, we will ask you about the work you have done in the past. If you cannot give us all of the information we need, we may try, with your permission, to get it from your employer or other person who knows about your work, such as a member of your family or a co-worker. When we need to consider your work experience to decide whether you are able to do work that is different from what you have done in the past, we will ask you to tell us about all of the jobs you have had in the last five years. You must tell us the dates you worked, all of the duties you did, and any tools, machinery, and equipment you used. We will need to know about the amount of walking, standing, sitting, lifting and carrying you did during the workday, as well as any other physical or mental duties of your job. If all of your work in the past five years has been arduous and unskilled, and you have very little education, we will ask you to tell us about all of your work from the time you first began working. This information could help you to get disability benefits.