5
The Listing of Impairments—Overview

The Listings serve as a screening tool at the initial decision stage to expedite the identification of individuals whose impairments clearly more than equal the level of severity that defines disability in the Social Security Act. Quick identification of obvious cases deserving benefits permits the Social Security Administration (SSA) to avoid a time-consuming and resource-intensive inquiry into all of the case facts. Using the Listings as an administrative expedient, SSA is able to process more cases more quickly and cost effectively than it would otherwise. As SSA explained in a February 10, 1994, final regulation, Revised Medical Criteria for Determination of Disability, Cardiovascular System (59 FR 6468):


The listings are intended to be a screening device by which we can identify and allow claims filed by the most obviously disabled individuals; they are not an all-inclusive list of disabilities under which all individuals must be found disabled.


In addition to efficiency, the Listings are intended to ensure that there is a medical basis for the disability and that all applicants receive equal treatment. As noted by SSA in a more recent regulatory notice from November 2001, Revised Medical Criteria for Determination of Disability, Musculoskeletal System and Related Criteria (66 FR 58010):


The Listings contain examples of some of the most frequently encountered impairments in the disability program. The criteria include specific symptoms, signs, and laboratory findings that are considered to characterize



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Improving the Social Security Disability Decision Process 5 The Listing of Impairments—Overview The Listings serve as a screening tool at the initial decision stage to expedite the identification of individuals whose impairments clearly more than equal the level of severity that defines disability in the Social Security Act. Quick identification of obvious cases deserving benefits permits the Social Security Administration (SSA) to avoid a time-consuming and resource-intensive inquiry into all of the case facts. Using the Listings as an administrative expedient, SSA is able to process more cases more quickly and cost effectively than it would otherwise. As SSA explained in a February 10, 1994, final regulation, Revised Medical Criteria for Determination of Disability, Cardiovascular System (59 FR 6468): The listings are intended to be a screening device by which we can identify and allow claims filed by the most obviously disabled individuals; they are not an all-inclusive list of disabilities under which all individuals must be found disabled. In addition to efficiency, the Listings are intended to ensure that there is a medical basis for the disability and that all applicants receive equal treatment. As noted by SSA in a more recent regulatory notice from November 2001, Revised Medical Criteria for Determination of Disability, Musculoskeletal System and Related Criteria (66 FR 58010): The Listings contain examples of some of the most frequently encountered impairments in the disability program. The criteria include specific symptoms, signs, and laboratory findings that are considered to characterize

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Improving the Social Security Disability Decision Process impairments severe enough to prevent a person from doing any gainful activity… . The Listings help to ensure that determinations and decisions regarding disability have a sound medical basis, that claimants receive equal treatment through the use of specific criteria, and that people who are disabled can be readily identified and awarded benefits if all other factors of entitlement or eligibility are met. In addition to providing equal treatment for all applicants, the Listings were intended to ensure adjudicative consistency: In the fall of 1959, only 3 years after the program was enacted, the Ways and Means Subcommittee on the Administration of the Social Security Program (the Harrison Subcommittee) held a series of hearings that focused in part on variation in decision making among the States. During these hearings, the Social Security Administration’s Deputy Commissioner, George Wyman, told the Subcommittee that the objective of achieving reasonable consistency represented “a real challenge.” However, as explained by former Commissioner of Social Security Robert Ball, who at that time was Deputy Director of the Bureau of Old-Age and Survivors Insurance, the agency had developed a set of medical guidelines for use in adjudication. These guides were developed for the express purpose of achieving “as high degree of equity in the application of this law across the country as possible” (SSAB, 2006:2). The Listings are organized by 14 major body systems (e.g., musculoskeletal impairments, respiratory impairments, neurological impairments). There are separate listings for adults (part A of the Listings) and children (part B of the Listings), although the adult criteria can be applied to children if the disease processes have a similar effect on adults and children. Altogether, there are more than 100 listed impairments. For each body system, the Listings begin with a narrative introduction that defines key concepts used in that body system. The introduction also identifies specific medical findings that may be required to show the existence of an impairment listed in that section. Symptoms alone cannot be the basis for establishing the existence of an impairment. The introduction is followed by the “Category of Impairments” section, which includes the specific criteria (medical signs, symptoms, and laboratory findings) that describe the required level of severity for each impairment listed in that body system. Although a few listings (e.g., certain cancers, amyotrophic lateral sclerosis) are evaluated based on diagnosis alone, most require a diagnosis in conjunction with some sort of assessment of impairment severity, either by the presence of specific clinical findings or by some sort of assessment of functional outcomes. If the evidence in a case establishes the presence of all the criteria required by one of the impairment listings, then the individual “meets” (i.e.,

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Improving the Social Security Disability Decision Process matches) that specific listing. However, even if the evidence does not show that an individual meets the exact requirements of a particular listing, the individual can still be found disabled at step 3 of the sequence if his or her impairment is equal in severity to the requirements of a listing, referred to as “medical equivalence.” Medical equivalence to a listing is established if the medical findings are at least equal in severity and duration to the listed findings. SSA compares the signs, symptoms, and laboratory findings in the medical evidence with the listing criteria for the individual’s impairment (or the listed impairment most like the individual’s impairment). If the individual has a combination of impairments, all of the medical findings of the combined impairments are compared to the most closely related listed impairment. However, medical equivalence cannot be established merely because an individual has many impairments. Medical equivalence is evaluated based on not only the medical evidence, but also on consideration of a designated physician’s medical judgment about equivalence (20 CFR §§ 404.1526 and 416.926; Social Security Ruling 86-8: Titles II and XVI: The Sequential Evaluation Process). See Box 5-1 for an illustration of how SSA applies the Listings. ORIGINS AND DEVELOPMENT OF THE LISTINGS SSA’s first experience with implementation of a disability benefit program occurred well before the Disability Freeze program in 1954 or the Disability Insurance Benefits Program in 1956. It came with the Civilian War Benefit (CWB) program, which was established in the early 1940s by executive, rather than legislative, action. CWB provided for payment of disability and medical benefits to civilians injured in the war effort. The disability benefit covered permanent, temporary, total, and partial disabilities. The disability evaluation policies and procedures included a list of conditions that automatically qualified an individual for permanent total disability benefits: Under CWB, an applicant was presumptively entitled to permanent total disability benefits if he/she suffered any of the following conditions: Loss of both feet, or permanent loss of use of both feet; Loss of both hands, or permanent loss of use of both hands; Loss of one hand and one foot, or permanent loss of use of one hand and one foot; Permanent loss of vision; or Any disability which requires the individual to be permanently bedridden.

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Improving the Social Security Disability Decision Process Box 5-1 How SSA Uses the Listings Listings Example—Peripheral Arterial Disease If “Susan” applies for disability insurance benefits, alleging that she is unable to work due to the effects of peripheral arterial disease, SSA first determines whether she meets the nondisability requirements for entitlement (e.g., sufficient work credit for disability insurance coverage). Assuming that the nondisability requirements are met, SSA evaluates her disability status, using the five-step sequential evaluation process. If she is not working at substantial gainful activity (step 1) and has an impairment that significantly limits her ability to perform basic work activities (step 2), SSA determines whether her impairment meets the requirements of the Listings. Peripheral arterial disease is evaluated in the “cardiovascular” body system, in section 4.00 of the Listings. For peripheral arterial disease, listed in section 4.12, the specific requirements are: 4.12 Peripheral arterial disease, as determined by appropriate medically acceptable imaging (see 4.00A3d, 4.00G2, 4.00G5, and 4.00G6), causing intermittent claudication (see 4.00G1) and one of the following: Resting ankle/brachial systolic blood pressure ratio of less than 0.50, OR Decrease in systolic blood pressure at the ankle on exercise (see 4.00G7a and 4.00C16—4.00C17) of 50 percent or more of pre-exercise level and requiring 10 minutes or more to return to pre-exercise level, OR Resting toe systolic pressure of less than 30 mm Hg (see 4.00G7c and 4.00G8), OR Resting toe/brachial systolic blood pressure ratio of less than 0.40 (see 4.00G7c). SSA compares Susan’s medical records to these specific requirements. To meet these requirements, the medical records must first establish the existence of peripheral arterial disease, using “medically acceptable imaging.” The listing shows, in the introductory text to the listing section, where the specific imaging requirements are to be found (in sections 4.00A3D, 4.00G2, 4.00G5, and 4.00G6). In addition, the impairment must cause “intermittent claudication.” The listing also shows where in the introductory text that requirement is explained. Finally, the evidence must document one of four specific clinical findings (blood pressure readings) that indicate impairment severity, described in subsections A, B, C, and D. If the medical records show that all these requirements are met, SSA determines that Susan is disabled without evaluating her work capacity, age, education, or work experience. SOURCE: CFR chapter 20, part 404, subpart P, appendix 1, section 4.00.

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Improving the Social Security Disability Decision Process The rating schedule for evaluating disability was organized according to six body systems (DeWitt, 1997): musculoskeletal organs of special sense the nose and throat scars and disfigurements neuropsychiatric disabilities dental and oral disabilities Although the full extent to which these CWB provisions served as a model for later disability evaluation procedures is unclear, there is an obvious similarity between the CWB approach and the process that eventually became know as the Listings. Later, as SSA staff worked on procedures to process large numbers of disability applications throughout the late 1940s, they fixed on a process that involved classifying applicants into eight groups according to disability severity. The most severely impaired were assigned to Group I, and the least severely affected placed in Group VIII. Later, the number of groups was reduced from eight to six, with each group including several examples of the kinds of impairments expected in the group. For Group I, total disability was considered automatic. The list of impairment examples (cited in Cowles, 2005:5-6) was: advanced pulmonary tuberculosis congestive heart failure aneurysm of aorta or branches myocardial infarction bronchiectasis colitis nephritis tuberculosis (kidneys) any cardiac lesion classified under Class IV (American Heart Association grouping) leukemia cerebral accident multiple sclerosis pellagra inoperable malignancies osteomyelitis of pelvis or vertebra tuberculosis of hip, spine, or larynx bronchial asthma

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Improving the Social Security Disability Decision Process Shortly after the Disability Freeze program was established by the Social Security Amendments of 1954, SSA appointed a 15-member medical advisory committee, which “recommended the issuance of evaluation guides and standards setting forth medical criteria for the evaluation of specific impairments with the degree of severity prescribed for each. The panel also suggested that factors such as age, education, training and experience may be important in the evaluation of disability, even though the law [at that time] did not specifically require consideration of these factors” (SSA, 1996). These evaluation guides later came to be known as the “Listing of Impairments.” From the beginning, the guides were conceived as a way to quickly identify allowance cases without performing a comprehensive analysis of an individual’s capacity to work: … we recognized that there were going to be a vast majority of the cases that might be pretty cut and dried on the medical evidence and where you didn’t have to go into vocational issues. And we wanted to find a way to get people through the listings and get them on. The listings were not intended administratively to close the case and foreclose the consideration of capacity to work and substantial activity of one kind or another. But the listings were a scrape to get people in (Hess, 1993). There was also an expectation that the Listings would apply in the vast majority of the cases, thus allowing the most efficient adjudication of large numbers of claims, as well as uniformity in adjudication: … we are faced with the need to adjudicate more cases in a short period of time than ever attempted by insurance companies or any other disability organization, including the Federal Government. The gross numbers, coupled with the operational complexities that arise when 48 States participate in the adjudicative process, demand a method which would assure reasonable uniformity in adjudication and which lends itself to a mass process. The proposed Guide lists impairments under medical diagnostic headings with a degree of severity for each that, if met, would allow a finding that an individual not actually working is unable to work…. While it is recognized that some people with the scheduled disability will engage in substantial gainful activity, the severity should be pitched at a level where experience shows us the majority cannot. These standards may then permit relatively quick decisions in 85 to 90 percent of all cases. If so, the Guide will be worthwhile, because it will have screened out the cases, one way or the other, where it is not necessary to go deeply into individualized adjudication, beyond the medical picture (SSA, 1955:6). Nevertheless, these guides were still supposed to allow some leeway for the exercise of professional judgment. Listings were not to be applied

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Improving the Social Security Disability Decision Process mechanically, and decision makers were expected to exercise judgment and arrive at decisions only after considering all the facts in the case (Cowles, 2005). Thus, the Listings were originally illustrative, rather than determinative. The first Listings were fairly brief. They were organized into 10 categories according to body system, similar to the Veterans Administration’s 1945 Schedule for Rating Disabilities: musculoskeletal system special sense organs respiratory system cardiovascular system digestive system genito-urinary system hemic and lymphatic system skin endocrine system nervous system, including neurology and psychiatry Each section began with a general introduction, followed by the specific Listing criteria, which focused more on the clinical criteria for diagnoses than functional consequences (Cowles, 2005:9). This focus on “objective” clinical criteria reflected some of the same concerns that framed the debate during the 1940s about establishing a disability program in the first place, and it compelled adoption of a definition of disability that relied heavily on objective medical evidence. “A strict, medically based definition of disability was considered necessary to avoid payment of unnecessary claims, thus keeping down costs; with an emphasis on objective medical evidence, as opposed to subjective symptoms, it was thought that decision making would be easier and more accurate” (Bloch, 1992:91). As explained by the 1948 Advisory Council on Social Security: To qualify for benefits, a disabled person would have to be incapable of self-support for an indefinite period—permanently and totally disabled. He would have to be unable, by reason of a disability medically demonstrable by objective tests, to perform any substantially gainful activity… . Benefits should be paid to an insured individual who is permanently and totally disabled. A “permanent and total disability” for the purpose of this program should mean any disability which is medically demonstrable by objective tests, which prevents the worker from performing any substantially gainful activity, and which is likely to be of long-continued and indefinite duration….

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Improving the Social Security Disability Decision Process The definition of “disability” used in a disability program will in large part determine the feasibility of administration and the costs of the program. The proposed definition is designed to establish a test of disability which will operate as a safeguard against unjustified claims. It is an administratively practicable test and it will facilitate the evaluation of permanent and total disabilities. The Council recommends that compensable disabilities be restricted to those which can be objectively determined by medical examination or tests. In this way, the problems involved in the adjudication of claims based on purely subjective symptoms can be avoided. Unless demonstrable by objective tests, such ailments as lumbago, rheumatism, and various nervous disorders would not be compensable. The danger of malingering which might be involved in connection with such claims would thereby be avoided (Advisory Council on Social Security, 1948:71, 74). Although the medically based Listings were a logical outgrowth of the medically based definition of disability eventually established in the 1954 Amendments to the Social Security Act (which had its origin in the 1948 advisory council report), nothing in the law has ever required SSA to have these kinds of guides or Listings. They were developed by SSA as an administrative tool to increase the efficiency of case processing. As SSA noted in a November 2001 final regulation, Revised Medical Criteria for Determination of Disability, Musculoskeletal System and Related Criteria (responding to a public comment that claimed that SSA’s proposed listing criteria were inconsistent with the Social Security Act, in 66 FR 58027): The [Social Security] Act does not, in fact, make any provision for the listings at all. The listings are an administrative convenience established by regulation to identify obviously disabled individuals. EVOLUTION OF THE LISTINGS For many years after they were first devised in 1955, the Listings did not appear anywhere in SSA’s disability regulations or other public information. Policy makers were concerned that widespread knowledge of the specific disability criteria could compromise program integrity: … we didn’t want to give those listings out to the public generally … we told the State agencies and we ourselves said these listings are not to be made public because they are the key to the bank. And doctors and litigators and others would know what the listings were. And it’s easy to write up a medical report. I don’t mean it’s a fraudulent medical report that is slanted in terms of highlighting those manifestations (Hess, 1993). Instead, the regulations included a brief list of examples of the kinds of impairments that might be considered disabling, while the actual Listings

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Improving the Social Security Disability Decision Process were only contained in the agency’s internal operating instructions. Following passage of the Freedom of Information Act in 1966, SSA began making the Listings available to the public by publishing them in its regulations. The first such publication occurred on August 20, 1968 (33 FR 11749). Between 1955 and 1967, when the Listings existed only in agency operating instructions, they were revised frequently, since they were “being developed based on operating experience” (Program Operations Manual System [POMS], section DI 34101.005). The last version of the Listings before their publication in the regulations (dated July 4, 1967) is still preserved in the SSA operating manual (POMS DI 34101.015). By 1967, the Listings had expanded considerably and evolved from a relatively short set of criteria that relied primarily on diagnoses and “disease specifications” to a much more elaborate set of standards that relied on specific observations, “highly-specific criteria involving signs, symptoms and laboratory findings,” and functional outcomes (Cowles, 2005:9, 12, 13). Another major development in the evolution of the Listings also occurred in 1968. The 1967 Amendments to the Social Security Act (Public Law [P.L.] 90-248) established a new disability benefit for widows and widowers age 50 and above. This benefit was based on a new, more restrictive definition of disability. To qualify, the widow or widower had to be unable to engage in any “gainful activity” (as compared with the standard for the existing disability program—inability to engage in substantial gainful activity). The new widows/widowers test was “based on the medical severity of the impairment and … not … on non-medical factors and work activity” (U.S. House of Representatives, 1974:118). The law required SSA to define this higher degree of severity by regulation, and SSA decided that the Listings represented the degree of severity contemplated in the law (SSA, 1968). Despite the fact that the widows/widowers disability standard was later revised to equal the degree of severity required for disability insurance benefits (in the 1990 Amendments to the Social Security Act, the Omnibus Budget Reconciliation Act of 1990 [P.L. 101-508]), “listing-level severity” has continued to represent a higher degree of severity than the statutory definition of disability (i.e., inability to engage in any gainful activity vs. inability to engage in any substantial gainful activity). The first significant revision to the Listings after 1968 occurred in 1977, when SSA published a new set of listings criteria that would apply to children under the age of 18 who were applying for Supplemental Security Income benefits (42 FR 14705). In 1979, SSA issued a comprehensive update and revision of all the adult Listings (44 FR 18170). In 1984, Congress directed SSA to revise its mental disorders listing criteria (Section 5(a) of P.L. 98-460, The Disability Benefits Reform Act of 1984). These revisions, which were published in the regulations on August 28, 1985 (50 FR 35038), marked the first time that SSA included an

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Improving the Social Security Disability Decision Process expiration date for any listing. The adult mental disorders listings were to expire three years from their effective date. As SSA explained in its Federal Register notice, “… [t]he dynamic nature of the diagnosis, evaluation and treatment of the mental disease process requires that the rules in this area be periodically revised and updated” (50 FR 35038). Later that year, SSA updated listings for most of the remaining body systems and added expiration dates for all the other body systems. Although the law does not require SSA to periodically update the criteria in the Listings, SSA noted in its December 6, 1985, Federal Register notice (50 FR 50068): Medical advancements in disability evaluation and treatment and program experience require that these listings be periodically reviewed and updated. … We intend to carefully monitor these listings over the period prescribed for each body system to ensure that they continue to meet program purposes. When changes are found to be warranted, the listings for that body system will be updated in the Federal Register again. Therefore, during the periods ranging from 4 to 8 years after the date of publication of these final rules, the listings under each body system will cease to be effective on the specified dates unless extended or revised and promulgated again. The 1985 updates (which took effect in January 1986) were the last comprehensive revision to the Listings. Since then, SSA has focused on updates that are more targeted—addressing a single body system or even individual listings. According to the Government Accountability Office (GAO), SSA’s Listings update activities were curtailed in the mid-1990s due to staff shortages, competing priorities, and lack of adequate research (GAO, 2002:7). One of the competing priorities in the mid-1990s was the agency’s effort to fundamentally redesign the disability decision-making process through business process reengineering—an initiative that became known as “disability redesign.” One component of the disability redesign was a project to develop a new approach to making disability decisions to replace the existing sequential evaluation process (SSA, 1994). However, by 1999, SSA had undertaken an internal reassessment of its disability initiatives and was no longer pursuing a new decision-making process. Rather, it had decided to focus on improving the current process and had resumed efforts to update the Listings (IOM and NRC, 2002). Since that time, SSA has completed a number of revisions and updates to specific sections of the Listings, including: Revised Medical Criteria for Determination of Disability, Endocrine System and Related Criteria (64 FR 46122, August 24, 1999) Addition of Medical Criteria for Evaluating Down Syndrome in Adults (65 FR 31800, May 19, 2000)

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Improving the Social Security Disability Decision Process Revised Medical Criteria for Evaluating Mental Disorders and Traumatic Brain Injury (65 FR 50745, August 21, 2000) Supplemental Security Income; Determining Disability for a Child Under Age 18 (65 FR 54747, September 11, 2000) [included limited revisions to the childhood listings] Revised Medical Criteria for Determination of Disability, Musculoskeletal System and Related Criteria (66 FR 58009, November 19, 2001) Technical Revisions to Medical Criteria for Determinations of Disability (67 FR 20018, April 24, 2002) Revised Medical Criteria for Evaluating Amyotrophic Lateral Sclerosis (68 FR 51689, August 28, 2003) Revised Medical Criteria for Evaluating Skin Disorders (69 FR 32260, June 9, 2004) Revised Medical Criteria for Evaluating Hematological Disorders and Malignant Neoplastic Diseases (69 FR 67017, November 15, 2004) Revised Medical Criteria for Evaluating Genitourinary Impairments (70 FR 38582, July 5, 2005) Revised Medical Criteria for Evaluating Impairments That Affect Multiple Body Systems (70 FR 51252, August 30, 2005) Revised Medical Criteria for Evaluating Cardiovascular Impairments (71 FR 2311, January 13, 2006) SSA has also initiated, but at the time of this report had not yet completed, several other Listings revisions, including: Revised Medical Criteria for Evaluating Growth Impairments (65 FR 37321, June 14, 2000 and 70 FR 53323, September 8, 2005) Revised Medical Criteria for Evaluating Impairments of the Digestive System (66 FR 57009, November 14, 2001, and 69 FR 64702, November 8, 2004) Revised Medical Criteria for Evaluating Mental Disorders (68 FR 12639, March 17, 2003) Revised Medical Criteria for Evaluating Immune System Disorders (68 FR 24896, May 9, 2003) Revised Medical Criteria for Evaluating Neurological Impairments (70 FR 19356, April 13, 2005) Revised Medical Criteria for Evaluating Respiratory System Disorders (70 FR 19358, April 13, 2005) Revised Medical Criteria for Evaluating Hearing Impairments and Disturbance of Labyrinthine-Vestibular Function (70 FR 19353, April 13, 2005) New Medical Criteria for Evaluating Language and Speech Disorders (70 FR 19351, April 13, 2005)

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Improving the Social Security Disability Decision Process Revised Medical Criteria for Evaluating Endocrine Disorders (70 FR 46792, August 11, 2005) Revised Medical Criteria for Evaluating Visual Disorders (70 FR 48342, August 17, 2005) REFERENCES Advisory Council on Social Security. 1948. Recommendations for Social Security legislation. The reports of the Advisory Council on Social Security to the Senate Committee on Finance. Part 2, Permanent and total disability. Available: www.ssa.gov/history/pdf/48advise6.pdf (accessed May 20, 2006). Bloch, F.S. 1992. Disability determination: The administrative process and the role of the medical professional. West London, CT: Greenwood Press. Cowles, A. 2005. History of the disability listings. Available: www.ssa.gov/history/DisabilityListings.html (accessed November 3, 2005). DeWitt, L. 1997. The Civilian War Benefits Program: SSA’s first disability program. Available: www.ssa.gov/history/civilwar.html (accessed November 3, 2005). GAO (Government Accountability Office). 2002. Social Security Administration: Fully updating disability criteria has implications for program design. Testimony before the Subcommittee on Social Security, Committee on Ways and Means, House of Representatives. GAO-02-919T. July 11, 2002. Available: www.gao.gov/new.items/d02919t.pdf (accessed November 17, 2005). Hess, A. 1993. Comments at the January 21, 1993 Disability Forum, The disability program: Its origins—our heritage. Its future—our challenge. Available: www.ssa.gov/history/dibforum93.html (accessed November 3, 2005). IOM and NRC (Institute of Medicine and National Research Council). 2002. The dynamics of disability: Measuring and monitoring disability for Social Security programs, edited by G.S. Wunderlich, D.P. Rice, and N.L. Amado. Washington, DC: National Academy Press. SSA (Social Security Administration). 1955. Summary report: Medical Advisory Committee meeting, February 9-10, 1955. Social Security Administration History Archives, Baltimore, MD. SSA. 1968. SSA program circular on disability insurance. Disability regulations—The listing of impairments. May 6, 1968. SSA. 1994. Plan for a new disability claim process. SSA Publication Number 01-005. Washington, DC: U.S. Government Printing Office. SSA. 1996. A history of the Social Security disability programs, January 1986. Available: www. ssa.gov/history/1986dibhistory.html (accessed November 3, 2005). SSAB (Social Security Advisory Board). 2006. Disability decisionmaking: Data and materials. Available: www.ssab.gov/documents/chartbook.pdf (accessed September 28, 2006). U.S. House of Representatives, Committee on Ways and Means. 1974. Committee staff report on the Disability Insurance Program. Available: www.ssa.gov/history/pdf/dibreport.pdf (accessed November 3, 2005).