EFFECTIVE/PUBLICATION DATE: 4/30/99
SSR 99-2p: POLICY INTERPRETATION RULING
TITLES II AND XVI:
EVALUATING CASES INVOLVING CHRONIC FATIGUE SYNDROME (CFS)
To restate and clarify the policies of the Social Security Administration for developing and evaluating title II and title XVI claims for disability on the basis of Chronic Fatigue Syndrome (CFS), also frequently known as Chronic Fatigue and Immune Dysfunction Syndrome.
Sections 216(i), 223(d), 223(f), 1614(a)(3) and 1614(a)(4) of the Social Security Act, as amended; Regulations No. 4, subpart P, sections 404.1505, 404.1508-404.1513, 404.1520, 404.1520a, 404.1521, 404.1523, 404.1526-404.1529, 404.1560-404.1569a and 404.1593-404.1594; and Regulations No. 16, subpart I, sections 416.905, 416.906, 416.908-416.913, 416.920, 416.920a, 416.921, 416.923, 416.924, 416.924b, 416.924c, 416.926, 416.926a, 416.927-416.929, 416.960-416.969a, 416.987, 416.993, 416.994, and 416.994a.
CFS is a systemic disorder consisting of a complex of symptoms that may vary in incidence, duration, and severity. The current case criteria for CFS, developed by an international group convened by the Centers for Disease Control and Prevention (CDC) as an identification tool and research definition, include a requirement for four or more of a specified list of symptoms. These constitute a patient's complaints as reported to a provider of treatment.
However, the Social Security Act (the Act) and our implementing regulations require that an individual establish disability based on the existence of a medically determinable impairment; i.e., one that can be shown by medical evidence, consisting of medical signs, symptoms and laboratory findings. Disability may not be established on the basis of an individual s statement of symptoms alone.
This Ruling explains that CFS, when accompanied by appropriate medical signs or laboratory findings, is a medically determinable impairment that can be the basis for a finding of "disability." It also provides guidance for the evaluation of claims involving CFS.
CFS constitutes a medically determinable impairment when it is accompanied by medical signs or laboratory findings, as discussed below. CFS may be a disabling impairment.
Definition of CFS
CFS is a systemic disorder consisting of a complex of symptoms that may vary in incidence, duration, and severity. It is characterized in part by prolonged fatigue that lasts 6 months or more and that results in substantial reduction in previous levels of occupational, educational, social, or personal activities. In accordance with criteria established by the CDC, a physician should make a diagnosis of CFS "only after alternative medical and psychiatric causes of chronic fatiguing illness have been excluded" (Annals of Internal Medicine, 121:953-9, 1994). CFS has been diagnosed in children, particularly adolescents, as well as in adults.
Under the CDC definition, the hallmark of CFS is the presence of clinically evaluated, persistent or relapsing chronic fatigue that is of new or definite onset (i.e., has not been lifelong), cannot be explained by another physical or mental disorder, is not the result of ongoing exertion, is not substantially alleviated by rest, and results in substantial reduction in previous levels of occupational, educational, social, or personal activities. Additionally, the current CDC definition of CFS requires the concurrence of 4 or more of the following symptoms, all of which must have persisted or recurred during 6 or more consecutive months of illness and must not have pre-dated the fatigue:
- Self-reported impairment in short-term memory or concentration severe enough to cause substantial reduction in previous levels of occupational, educational, social, or personal activities;
- Sore throat;
- Tender cervical or axillary lymph nodes;
- Muscle pain;
- Multi-joint pain without joint swelling or redness;
- Headaches of a new type, pattern, or severity;
- Unrefreshing sleep; and
- Postexertional malaise lasting more than 24 hours.
Requirement for a Medically Determinable Impairment
Sections 216(i) and 1614(a)(3) of the Act define "disability" as the inability to engage in any substantial gainful activity (SGA) by reason of any medically determinable physical or mental impairment (or combination of impairments) 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. Sections 223(d)(3) and 1614(a)(3)(D) of the Act, and 20 CFR 404.1508 and 416.908 require that an impairment result from anatomical, physiological, or psychological abnormalities that can be shown by medically acceptable clinical and laboratory diagnostic techniques. The Act and regulations further require that an impairment be established by medical evidence that consists of signs, symptoms, and laboratory findings, and not only by an individual's statement of symptoms.
Under the CDC definition, the diagnosis of CFS can be made based on an individual s reported symptoms alone once other possible causes for the symptoms have been ruled out. However, the foregoing statutory and regulatory provisions require that, for evaluation of claims of disability under the Act, there must also be medical signs or laboratory findings before the existence of a medically determinable impairment may be established.
Establishing the Existence of a Medically Determinable Impairment
The following medical signs and laboratory findings establish the existence of a medically determinable impairment in individuals who have CFS. Although no specific etiology or pathology has yet been established for CFS, many research initiatives continue, and some progress has been made in ameliorating symptoms in selected individuals. With continuing scientific research, new medical evidence may emerge that will further clarify the nature of CFS and provide greater specificity regarding the clinical and laboratory diagnostic techniques that should be used to document this disorder.
Because of this, the medical criteria discussed below are only examples of signs and laboratory findings that will establish the existence of a medically determinable impairment; they are not all-inclusive. As progress is made in medical research into CFS, additional signs and laboratory findings may also be found that can be used to establish that individuals with CFS have a medically determinable impairment. The existence of CFS may be documented with medical signs or laboratory findings other than those listed below, provided that such documentation is consistent with medically accepted clinical practice and is consistent with the other evidence in the case record.
Examples of medical signs that establish the existence of a medically determinable impairment
For purposes of Social Security disability evaluation, one or more of the following medical signs clinically documented over a period of at least 6 consecutive months establishes the existence of a medically determinable impairment for individuals with CFS:
- Palpably swollen or tender lymph nodes on physical examination;
- Nonexudative pharyngitis;
- Persistent, reproducible muscle tenderness on repeated examinations, including the presence of positive tender points; or,
- Any other medical signs that are consistent with medically accepted clinical practice and are consistent with the other evidence in the case record.
Examples of laboratory findings that establish the existence of a medically determinable impairment
At this time, there are no specific laboratory findings that are widely accepted as being associated with CFS. However, the absence of a definitive test does not preclude reliance upon certain laboratory findings to establish the existence of a medically determinable impairment in persons with CFS. Therefore, the following laboratory findings establish the existence of a medically determinable impairment in individuals with CFS:
- An elevated antibody titer to Epstein-Barr virus (EBV) capsid antigen equal to or greater than 1:5120, or early antigen equal to or greater than 1:640;
- An abnormal magnetic resonance imaging (MRI) brain scan;
- Neurally mediated hypotension as shown by tilt table testing or another clinically accepted form of testing; or,
- Any other laboratory findings that are consistent with medically accepted clinical practice and are consistent with the other evidence in the case record; for example, an abnormal exercise stress test or abnormal sleep studies, appropriately evaluated and consistent with the other evidence in the case record.
Some individuals with CFS report ongoing problems with short-term memory, information processing, visual-spatial difficulties, comprehension, concentration, speech, word-finding, calculation, and other symptoms suggesting persistent neurocognitive impairment. When ongoing deficits in these areas have been documented by mental status examination or psychological testing, such findings constitute medical signs or (in the case of psychological testing) laboratory findings that establish the presence of a medically determinable impairment.
Individuals with CFS may also exhibit medical signs, such as anxiety or depression, indicative of the existence of a mental disorder. When such medical signs are present and appropriately documented, the existence of a medically determinable impairment is established.
- General. Claims involving CFS are adjudicated using the
sequential evaluation process, just as for any other impairment. Once a
medically determinable impairment has been found to exist (see discussion
above), the severity of the impairment(s) must be established. The
severity of an individual's impairment(s) is determined based on the
totality of medical signs, symptoms, and laboratory findings, and the
effects of the impairment(s), including any related symptoms, on the
individual's ability to function.
Also, several other disorders (including, but not limited to, FMS, multiple chemical sensitivity, and Gulf War Syndrome, as well as various forms of depression, and some neurological and psychological disorders) may share characteristics similar to those of CFS. When there is evidence of the potential presence of another disorder that may adequately explain the individual's symptoms, it may be necessary to pursue additional medical or other development.
- Step 2. When an adjudicator finds that an individual with CFS has a medically determinable impairment, he or she must consider that the individual has an impairment that could reasonably be expected to produce the individual s symptoms associated with CFS, as required in 20 CFR 404.1529(b) and 416.929(b), and proceed to evaluate the intensity and persistence of the symptoms. Thus, if an adjudicator concludes that an individual has a medically determinable impairment, and the individual alleges fatigue, pain, symptoms of neurocognitive problems, or other symptoms consistent with CFS, these symptoms must be considered in deciding whether the individual's impairment is "severe" at step 2 of the sequential evaluation process and at any later steps reached in the sequential evaluation process. If fatigue, pain, neurocognitive symptoms, or other symptoms are found to cause a limitation or restriction having more than a minimal effect on an individual's ability to perform basic work activities, the adjudicator must find that the individual has a "severe" impairment. See SSR 96-3p, "Titles II and XVI: Considering Allegations of Pain and Other Symptoms in Determining Whether a Medically Determinable Impairment is Severe."
- Step 3. When an individual is found to have a severe
impairment, the adjudicator must proceed with the sequential evaluation
process and must next consider whether the individual's impairment is of
the severity contemplated by the Listing of Impairments contained in
appendix 1, subpart P of 20 CFR part 404. Inasmuch as CFS is not a listed
impairment, an individual with CFS alone cannot be found to have an
impairment that meets the requirements of a listed impairment; however,
the specific findings in each case should be compared to any pertinent
listing to determine whether medical equivalence may
Further, in cases in which individuals with CFS have psychological manifestations related to CFS, consideration should always be given to whether the individual's impairment meets or equals the severity of any impairment in the mental disorders listings in 20 CFR, part 404, subpart P, appendix 1, sections 12.00 ff. or 112.00 ff.
- Steps 4 and 5. For those impairments that do not meet or equal
the severity of a listing, an assessment of residual functional capacity
(RFC) must be made, and adjudication must proceed to the fourth and, if
necessary, the fifth step of the sequential evaluation
process. In assessing RFC,
all of the individual's symptoms must be considered in deciding how such
symptoms may affect functional capacities. See
SSR 96-7p, "Titles II and XVI:
Evaluation of Symptoms in Disability Claims: Assessing the Credibility of
an Individual's Statements" and SSR
96-8p, "Titles II and XVI: Assessing Residual Functional Capacity in
If it is determined that the individual's impairment(s) precludes the performance of past relevant work (or if there was no past relevant work), a finding must be made about the individual's ability to perform other work. The usual vocational considerations (see 20 CFR 404.1560-404.1569a and 416.960-416.969a) must be applied in determining the individual's ability to perform other work.
Many individuals with CFS are "younger individuals," ages 18 through 49 (see 20 CFR 404.1563 and 416.963). Age, education, and work experience are not usually considered to limit significantly the ability of individuals under age 50 to make an adjustment to other work, including unskilled sedentary work. However, a finding of disabled is not precluded for those individuals under age 50 who do not meet all of the criteria of a specific rule and who do not have the ability to perform a full range of sedentary work. The conclusion about whether such individuals are disabled will depend primarily on the nature and extent of their functional limitations or restrictions. Thus, if it is found that an individual is able to do less than the full range of sedentary work, refer to SSR 96-9p, "Titles II and XVI: Determining Capability to Do Other Work -- Implications of a Residual Functional Capacity for Less Than a Full Range of Sedentary Work." As explained in that Ruling, whether the individual will be able to make an adjustment to other work requires adjudicative judgment regarding factors such as the type and extent of the individual's limitations or restrictions and the extent of the erosion of the occupational base for sedentary work.
- Duration. The medical signs and symptoms of CFS fluctuate in
frequency and severity and often continue over a period of many months or
years. Thus, appropriate documentation should include a longitudinal
clinical record of at least 12 months prior to the date of application,
unless the alleged onset of CFS occurred less than 12 months in the past,
or unless a fully favorable determination or decision can be made without
additional documentation. The record should contain detailed medical
observations, treatment, the individual's response to treatment, and a
detailed description of how the impairment limits the individual's ability
to function over time.
When the alleged onset of disability secondary to CFS occurred less than 12 months before adjudication, the adjudicator must evaluate the medical evidence and project the degree of impairment severity that is likely to exist at the end of 12 months. Information about treatment and response to treatment as well as any medical source opinions about the individual's prognosis at the end of 12 months are helpful in deciding whether the medically determinable impairment(s) is expected to be of disabling severity for at least 12 consecutive months.
- Continuing Disability Reviews. In those cases in which an individual is found to have a disability based on CFS but medical improvement is anticipated, an appropriate continuing disability review should be scheduled based on the probability of cessation under the Medical Improvement Review Standard. This standard takes into account relevant individual case facts such as the combined severity of other chronic or static impairments and the individual's vocational factors.
- General. As with all claims for disability under both title II
and title XVI, documentation of medical signs or laboratory findings in
cases involving CFS is critical to establishing the presence of a
medically determinable impairment. In cases in which CFS is alleged,
longitudinal clinical records reflecting ongoing medical evaluation and
treatment from the individual's medical sources, especially treating
sources, are extremely helpful in documenting the presence of any medical
signs or laboratory findings, as well as the individual's functional
status over time. Every reasonable effort should be made to secure all
available, relevant evidence in cases involving CFS to ensure appropriate
and thorough evaluation.
Generally, evidence for the 12-month period preceding the month of application should be requested unless there is reason to believe that development of an earlier period is necessary, or unless the alleged onset of disability is less than 12 months before the date of the application.
- Recontacting Medical Sources/Consultative Examinations. If the adjudicator finds that the evidence is inadequate to determine whether the individual is disabled, he or she must first recontact the individual's treating or other medical source(s) to determine whether the additional information needed is readily available, in accordance with 20 CFR 404.1512 and 416.912. Only after the adjudicator determines that the information needed is not readily available from the individual's health care provider(s), or that the necessary information or clarification cannot be sought from the individual's health care provider(s), should the adjudicator proceed to arrange for a consultative examination(s) in accordance with 20 CFR 404.1519a and 416.919a. The type of consultative examination(s) purchased will depend on the nature of the individual's symptoms and the extent of the evidence already in the case record.
- Resolution of Conflicts. It should be noted that conflicting
evidence in the medical record is not unusual in cases of CFS due to the
complicated diagnostic process involved in these cases. Clarification of
any such conflicts in the medical evidence should be sought first from the
individual's treating or other medical sources.
Medical opinions from treating sources about the nature and severity of an individual's impairment(s) are entitled to deference and may be entitled to controlling weight. If we find that a treating source's medical opinion on the issue(s) of the nature and severity of an individual's impairment(s) is well-supported by medically acceptable clinical and laboratory diagnostic techniques and is not inconsistent with the other substantial evidence in the case record, the adjudicator will give it controlling weight. (See SSR 96-2p, "Titles II and XVI: Giving Controlling Weight to Treating Source Medical Opinions," and SSR 96-5p, "Titles II and XVI: Medical Source Opinions on Issues Reserved to the Commissioner.")
- Assessing Credibility. In accordance with
SSR 96-7p, if the existence of a
medically determinable impairment that could reasonably be expected to
produce the symptoms has been established, as outlined above, but an
individual's statements about the intensity, persistence, or functionally
limiting effects of symptoms are not substantiated by objective medical
evidence, the adjudicator must consider all of the evidence in the case
record, including any statements by the individual and other persons
concerning the individual's symptoms. The adjudicator must then make a
finding on the credibility of the individual's statements about symptoms
and their functional effects. When additional information is needed to
assess the credibility of the individual's statements about symptoms and
their effects, the adjudicator must make every reasonable effort to obtain
available information that could shed light on the credibility of the
Treating and other medical sources. In evaluating credibility, the adjudicator should ask the treating or other medical source(s) to provide information about the extent and duration of an individual's impairment(s), including observations and opinions about how well the individual is able to function, the effects of any treatment, including side effects, and how long the impairment(s) is expected to limit the individual's ability to function. Opinions from an individual's medical sources, especially treating sources, concerning the effects of CFS on the individual's ability to function in a sustained manner in performing work activities or in performing activities of daily living are important in enabling adjudicators to draw conclusions about the severity of the impairment(s) and the individual's RFC. In this regard, any information a medical source is able to provide contrasting the individual's impairment(s) and functional capacities since the alleged onset of CFS with the individual's status prior to the onset of CFS will be helpful in evaluating the individual's impairment(s) and its functional consequences.
Third-party information, including evidence from medical sources who are not acceptable medical sources for the purpose of establishing the existence of a medically determinable impairment, but who have provided services to the individual, may be very useful in deciding the individual's credibility. Information other than an individual's allegations and reports from the individual's treating sources helps to assess an individual's ability to function on a day-to-day basis and to depict the individual's capacities over a period of time. Such evidence includes, but is not limited to:
- Information from neighbors, friends, relatives, or clergy;
- Statements from such individuals as past employers, rehabilitation counselors, or school teachers about the individual's impairment(s) and the effects of the impairment(s) on the individual's functioning in the work place, rehabilitation facility, or educational institution;
- Statements from other practitioners with knowledge of the individual, e.g., nurse-practitioners, physicians' assistants, naturopaths, therapists, social workers, and chiropractors;
- Statements from other sources with knowledge of the individual's ability to function in daily activities; and
- The individual's own record (such as a diary, journal, or notes) of his or her own impairment(s) and its impact on function over time.
The adjudicator should carefully consider this information when making findings about the credibility of the individual's allegations regarding functional limitations or restrictions.
This Ruling is effective on the date of its publication in the Federal Register.
SSR 96-2p, "Titles II and XVI: Giving Controlling Weight to Treating Source Medical Opinions," SSR 96-3p, "Titles II and XVI: Considering Allegations of Pain and Other Symptoms in Determining Whether a Medically Determinable Impairment is Severe," SSR 96-4p, "Titles II and XVI: Symptoms, Medically Determinable Physical and Mental Impairments, and Exertional and Nonexertional Limitations," SSR 96-5p, "Titles II and XVI: Medical Source Opinions on Issues Reserved to the Commissioner," SSR 96-7p, "Titles II and XVI: Evaluation of Symptoms in Disability Claims: Assessing the Credibility of an Individual's Statements," SSR 96-8p, "Titles II and XVI: Assessing Residual Functional Capacity in Initial Claims," and SSR 96-9p, "Titles II and XVI: Determining Capability to Do Other Work -- Implications of a Residual Functional Capacity for Less Than a Full Range of Sedentary Work."
 Except for statutory blindness.
 For individuals under age 18 claiming benefits under title XVI, disability will be established if the individual is suffering from a medically determinable physical or mental impairment (or combination of impairments) that results in "marked and severe functional limitations." See section 1614(a)(3)(C) of the Act and 20 CFR 416.906. However, for clarity, the following discussions refer only to claims of individuals claiming disability benefits under title II and individuals age 18 or older claiming disability benefits under title XVI. The concepts in this ruling, however, are also intended to apply in determining disability based on CFS for individuals under age 18 under title XVI.
 There is considerable overlap of symptoms between CFS and Fibromyalgia Syndrome (FMS), but individuals with CFS who have tender points have a medically determinable impairment. Individuals with impairments that fulfill the American College of Rheumatology criteria for FMS (which includes a minimum number of tender points) may also fulfill the criteria for CFS. However, individuals with CFS who do not have the specified number of tender points to establish FMS, will still be found to have a medically determinable impairment.
 It should be noted that standard laboratory test results in the normal range are characteristic for many individuals with CFS, and should not be relied upon to the exclusion of all other clinical evidence in decisions regarding the presence and severity of a medically determinable impairment.
 In evaluating title XVI claims for disability benefits for individuals under age 18, consideration must also be given to the possibility of functional equivalence. See 20 CFR 416.926a.
 These steps of the sequential evaluation process are not applicable to claims for benefits under title XVI for individuals under age 18. See 20 CFR 416.924.
 However, "younger individuals" ages 45-49 who are illiterate in English or unable to communicate in English, whose past work was unskilled (or who had no past relevant work), or who have no transferable skills, and who are limited to a full range of sedentary work, must be found disabled under rule 201.17 in Table No. 1 of appendix 2 of the Medical-Vocational Guidelines in 20 CFR part 404.
 To meet the statutory requirement for "disability," an individual must have been unable to engage in any SGA by reason of any medically determinable physical or mental impairment which is 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. Thus, the existence of an impairment for 12 continuous months is not controlling; rather, it is the existence of a disabling impairment which has lasted or can be expected to last for at least 12 months that meets the duration requirement of the Act.
 We may not seek additional evidence or clarification from a medical source when we know from past experience that the source either cannot or will not provide the necessary findings.
 A medical source opinion that an individual is "disabled" or "unable to work," has an impairment(s) that meets or is equivalent in severity to the requirements of a listing, has a particular residual functional capacity (RFC), that concerns whether an individual's RFC prevents him or her from doing past relevant work, or that concerns the application of vocational factors, is an opinion on an issue reserved to the Commissioner. Every such opinion must still be considered in adjudicating a disability claim; however, the adjudicator will not give any special significance to such an opinion because of its source. See SSR 96-5p, "Titles II and XVI: Medical Source Opinions on Issues Reserved to the Commissioner."