At step three of the sequential evaluation process, the adjudicator must determine whether the claimant's diagnosable medical impairments meet or equal a Listing of Impairments. The Listing of Impairments describes the medical criteria for each body system considered severe enough to prevent an individual from doing any gainful activity. Essentially, the listings are a "short-cut" to getting on disability. Examples of medical diagnoses that meet the Listing of Impairments would include small cell carcinoma of the lungs (Listing 13.14B), amputation of both hands (Listing 1.05A), or an aortic aneurysm with uncontrolled dissection (Listing 4.10). Approximately 25-30% of all disabled beneficiaries meet the level of severity for listings.
As my colleague indicated in her post last week, an adult must suffer from a "medically determinable impairment" in order to receive disability benefits, and not every impairment is easily proven by clinical or laboratory findings. There is no gold standard, for example, in making diagnosis of rheumatoid arthritis. Similarly, there are no widely accepted formal diagnostic criteria for myasthenia gravis. Though many claimants suffer from symptoms of pain or fatigue, a "symptom" is not a medically determinable impairment under SSR 96-4p. Thus, further rules may be necessary to establish a medical impairment.
The Social Security Administration is constantly working to update their "Listing of Impairments" / list of disorders eligible for Social Security Disability. This year, the SSA will ask for public comment (part of the approval process for such changes) on musculoskeletal disorders.