http://www.ssa.gov/disability/professionals/cfs-pub063.htm
Social Security Administration
When an individual with Chronic Fatigue Syndrome (CFS), also known as Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS), applies for Social Security disability benefits, we must decide whether he or she is disabled under the law. We base our decision on information you provide and other evidence, including information provided by the individual. The following guidelines will help you understand the kind of information we need to evaluate claims filed by individuals with CFS.