The Institute of Medicine (IOM) Committee on Improving the Disability Decision Process has been working since it first met in January 2005 to develop recommendations to the Social Security Administration (SSA) on how to improve the medical aspects of its disability determination process. By law, Social Security can only pay benefits to those unable to engage in substantial gainful activity because of a "medically determinable physical or mental impairment which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months (emphasis added)." Medical and psychological expertise is critical both in developing the criteria for measuring the severity and functional impact of an impairment or impairments on an applicant's ability to work and in applying the criteria to individual cases where the medical evidence does not clearly meet the criteria in the eyes of a nonmedical disability examiner.