Administrative Law Judges may request medical experts to attend a Social Security Disability Hearing and provide expert testimony about physical or mental medical conditions or issues which are complex. Medical experts are not employed by the Social Security Administration but are on an approved list maintained by each Social Security Disability Hearing Office. Medical experts receive compensation for their appearance at each disability hearing. The Social Security Administration, however, will incur the cost of paying the expert, and there is no cost for the disability claimant. Medical experts are traditionally retired doctors or practicing doctors who have extensive medical knowledge and help the Administrative Law Judge make a well-informed decision based on the medical evidence. Medical experts are hired to give their medical opinion about the claimant's impairments and their mental and physical functional limitations. The Administrative Law Judge may ask the medical expert for an oral residual functional capacity statement based on their medical expertise. Social Security Disability attorneys can be hired to attend a claimant's Social Security Disability hearing and cross-examine and refute a medical expert's testimony.