What is Medically Determinable Impairment?

Social Security requires a medically determinable physical or mental impairment as the basis for a finding of disability. The “medically determinable” language is part of the definition of disability in the Social Security Act itself. See 42 U.S.C. 423(d)(1)(A). A physical or mental impairment must be established by medical evidence consisting of signs, symptoms, and laboratory findings, not only by your statement of symptoms. See 20 C.F.R. 404.1508. Signs, symptoms and laboratory findings are defined by regulation. Social Security Ruling 96-4p also discusses this requirement, and is a good starting place for research on the issue. The requirement for a medically determinable impairment (MDI) is to ensure there is a valid basis for your claim, and for the functional limitations you are asserting. Some illnesses can be problematic in the MDI department, however. Social Security has had to clarify that the MDI requirement is met for certain illnesses. For example, Social Security has issued rulings stating that that chronic fatigue syndrome, post-polio sydrome and fibromyalgia can satisfy the requirement for a medically determinable impairment. The rulings set forth criteria for those diagnoses. When those criteria are met, these impairments can medically support a determination of Social Security disability. I have had recent MDI difficulty with Lyme disease. Laboratory testing for Lyme disease tests for the presence of the antibody, not the disease itself. It is common to receive false negatives and inconsistent results between different lab tests. As a result, you can run into MDI problems. However, the SSA has no criteria for what signs, symptoms and findings must be present for a diagnosis of Lyme disease, and has issued no ruling on this topic. So if your doctor tests you for Lyme disease, diagnoses you with Lyme disease, and treats you...