Established in 1956, DI is an insurance program that provides benefits to workers who are unable to work because of severe long-term disability. In 2001, DI provided $54.2 billion in cash benefits to 6.1 million disabled workers. Workers who have worked long enough and recently enough are insured for coverage under the DI program. DI beneficiaries receive cash assistance and, after a 24-month waiting period, Medicare coverage. Once found eligible for benefits, disabled workers continue to receive benefits until they die, return to work and earn more than allowed by program rules, are found to have medically improved to the point of having the ability to work, or reach full retirement age (when disability benefits convert to retirement benefits). To help ensure that only eligible beneficiaries remain on the rolls, SSA is required by law to conduct continuing disability reviews for all DI beneficiaries to determine whether they continue to meet the disability requirements of the law. SSI, created in 1972, is an income assistance program that provides cash benefits for disabled, blind, or aged individuals who have low income and limited resources. In 2001, SSI provided $19 billion in federal cash benefits to 3.8 million disabled and blind individuals age 18-64. Unlike the DI program, SSI has no prior work requirement. In most cases, SSI eligibility makes recipients eligible for Medicaid benefits. SSI benefits terminate for the same reasons as DI benefits, although SSI benefits also terminate when a recipient no longer meets SSI income and resource requirements (SSI benefits do not convert to retirement benefits when the individual reaches full retirement age). The law requires that continuing disability reviews be conducted for some SSI recipients for continuing eligibility. The Social Security Act’s definition of disability for adults under DI and SSI is the same: an individual must have a medically determinable physical or mental impairment that (1) has lasted or is expected to last at least 1 year or to result in death and (2) prevents the individual from engaging in substantial gainful activity. Moreover, the definition specifies that for a person to be determined to be disabled, the impairment must be of such severity that the person not only is unable to do his or her previous work but, considering his or her age, education, and work experience, is unable to do any other kind of substantial work that exists in the national economy. SSA regulations and guidelines provide further specificity in determining eligibility for DI and SSI benefits. For instance, SSA has developed the Listing of Impairments (the Medical Listings) to describe medical conditions that SSA has determined are severe enough ordinarily to prevent an individual from engaging in substantial gainful activity. SSA has also developed a procedure to assess applicants who do not have an impairment that meets or equals the severity of the Medical Listings. The procedure helps determine whether an applicant can still perform work done in the past or other work that exists in the national economy. While not expressly required by law to update the criteria used in the disability determination process, SSA has stated that it would update them to reflect current medical criteria and terminology. Over the years, SSA has periodically taken steps to update its Medical Listing. The last general update to the Medical Listing occurred in 1985. In 2000, the most common impairments among DI’s disabled workers were mental disorders and musculoskeletal conditions (see fig.1). These two conditions also were the fastest growing conditions since 1986, increasing by 7 and 5 percentage points, respectively. In 2000, the most common impairments among the group of SSI blind and disabled adults age 18-64 were mental disorders and mental retardation (see fig. 2). Mental disorders was the fastest growing condition among this population since 1986, increasing by 9 percentage points. Scientific advances, changes in the nature of work, and social changes have generally enhanced the potential for people with disabilities to work. Medical advancements and assistive technologies have given more independence to some individuals. Moreover, the economy has become more service- and knowledge-based, presenting both opportunities and some new challenges for people with disabilities. Finally, social changes have altered expectations for people with disabilities. For instance, the Americans with Disabilities Act fosters the expectation that people with disabilities can work and have the right to work. Recent scientific advances in medicine and assistive technology and changes in the nature of work and the types of jobs in our national economy have generally enhanced the potential for people with disabilities to perform work-related activities. Advances in medicine have led to a deeper understanding of and ability to treat disease and injury. Medical advancements in treatment (such as organ transplantations), therapy, and rehabilitation have reduced the functional limitations of some medical conditions and have allowed individuals to live and work with greater independence. Also, assistive technologies—such as advanced wheelchair design, a new generation of prosthetic devices, and voice recognition systems—afford greater capabilities for some people with disabilities than were available in the past. At the same time, the nature of work has changed in recent decades as the national economy has moved away from manufacturing-based jobs to service- and knowledge-based employment. In the 1960s, earning capacity became more related to a worker’s skills and training than to his or her ability to perform physical labor. Following World War II and the Korean Conflict, advancements in technology, including computers and automated equipment, reduced the need for physical labor. The goods-producing sector’s share of the economy—mining, construction, and manufacturing—declined from about 44 percent in 1945 to about 18 percent in 2000. The service-producing industry’s share, on the other hand—such areas as wholesale and retail trade; transportation and public utilities; federal, state and local government; and finance, insurance, and real estate—increased from about 57 percent in 1945 to about 72 percent in 2000. Although there may be more an individual with a disability can do in today’s world of work than was available when the DI and SSI programs were first designed, today’s work world is not without demands. Some jobs require standing for long hours, and other jobs, such as office work, require social abilities. These characteristics can pose particular challenges for some persons with certain physical or mental impairments. Moreover, other trends—such as downsizing and the growth in contingent workers—can limit job security and benefits, like health insurance, that most persons with disabilities require for participation in the labor force. Whether these changes make it easier or more difficult for a person with a disability to work appears to depend very much on the individual’s impairment and other characteristics, according to experts. Social change has promoted the goals of greater inclusion of and participation by people with disabilities in the mainstream of society, including adults at work. For instance, over the past 2 decades, people with disabilities have sought to remove environmental barriers that impede them from fully participating in their communities. Moreover, the Americans with Disabilities Act supports the full participation of people with disabilities in society and fosters the expectation that people with disabilities can work and have the right to work. The Americans with Disabilities Act prohibits employers from discriminating against qualified individuals with disabilities and requires employers to make reasonable workplace accommodations unless it would impose an undue hardship on the business. The disability criteria used in the DI and SSI disability programs to help determine who is qualified to receive benefits have not been fully updated to reflect these advances and changes. SSA is currently in the midst of a process that began around the early 1990s to update the medical criteria they use to make eligibility decisions, but the progress is slow. Moreover, some changes resulting from treatment advances and assistive technologies are not fully incorporated into the decision-making process due to program design. In addition, the disability criteria have not incorporated labor market changes. In determining the effect that impairments have on individuals’ earning capacity, SSA continues to use outdated information about the types and demands of jobs in the economy. SSA’s current effort to update the disability criteria began in the early 1990s. Between 1991 and 1993, SSA published for public comment the changes it was proposing to make to 7 of the14 body systems in its Medical Listings. By 1994, the proposed changes to 5 of these 7 body systems were finalized. The agency’s efforts to update the Medical Listings were curtailed in the mid-1990s due to staff shortages, competing priorities, and lack of adequate research on disability issues. SSA resumed updating the Medical Listings in 1998. Since then, SSA has taken some positive steps in updating portions of the medical criteria it uses to make eligibility decisions, although progress is slow. As of early 2002, SSA has published the final updated criteria for 1 of the 9 remaining body systems not updated in the early 1990s (musculoskeletal) and a portion of a second body system (mental disorders). SSA also plans to update again the 5 body systems that were updated in the early 1990s. In addition, SSA has asked the public to comment on proposed changes for several other body systems. After reviewing the schedule and timing for the revisions, SSA recently pushed back the completion date for publishing proposed changes for all remaining body systems to the end of 2003. The revised schedule does not list target dates, with one exception, for submitting changes for final clearance to the Office of Management and Budget. SSA’s slow progress in completing the updates could undermine the purpose of incorporating medical advances into its medical criteria. For example, the criteria for musculoskeletal conditions—a common impairment among persons entering DI—were updated in 1985. Then, in 1991, SSA began developing new criteria and published its proposed changes in 1993 but did not finalize the changes until 2002; therefore, changes made to the musculoskeletal criteria in 2002 were essentially based on SSA’s review of the field in the early 1990s. SSA officials told us that in finalizing the criteria, they reviewed the changes identified in the early 1990s and found that little had taken place since then to warrant changes to the proposed criteria.