POLICY INTERPRETATION RULING
TITLES II AND XVI: EVALUATING CASES INVOLVING CHRONIC FATIGUE SYNDROME (CFS)
PURPOSE: This SSR clarifies our policy on how we develop evidence that a person has a medically
determinable impairment (MDI) of chronic fatigue syndrome (CFS) and how we evaluate
this impairment in disability claims and continuing disability reviews under titles
II and XVI of the Social Security Act (Act).
CITATIONS (AUTHORITY): 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,
404.1519a, 404.1520, 404.1520a, 404.1521, 404.1523, 404.1526-404.1529, 404.1545, 404.1560-404.1569a,
404.1593, 404.1594, appendices 1 and 2; Regulations No. 16, subpart I, sections 416.902,
416.905, 416.906, 416.908-416.913, 416.919a, 416.920, 416.920a, 416.921, 416.923,
416.924, 416.924a, 416.926, 416.926a, 416.927-416.929, 416.945, 416.960-416.969a,
416.987, 416.993, 416.994, and 416.994a.
INTRODUCTION: CFS is a systemic disorder consisting of a complex of symptoms that may vary in incidence,
duration, and severity. In 1994, an international panel convened by the Centers for
Disease Control and Prevention (CDC) developed a case definition for CFS that serves
as an identification tool and research definition. In 2003, an expert subcommittee of Health Canada, the Canadian health agency, convened
a consensus workshop that developed a clinical case definition for CFS, known as the
Canadian Consensus Criteria (CCC). In 2011, a private international group developed guidelines, known as the International
Consensus Criteria (ICC), for diagnosing myalgic encephalomyelitis (ME). Members of this international group and other medical experts consider ME to be a
subtype of CFS. We adapted the CDC criteria, and to some extent the CCC and ICC, when we formulated
the criteria in this SSR.
We consider a person to be “disabled” if he or she is unable to engage in any substantial gainful activity by reason of
any medically determinable physical or mental impairment(s) 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. We require that an MDI result
from anatomical, physiological, or psychological abnormalities, as shown by medically
acceptable clinical and laboratory diagnostic techniques. The Act and our regulations further require that the impairment be established by
medical evidence that consists of signs, symptoms, and laboratory findings; therefore,
a claimant may not be found disabled on the basis of a person’s statement of symptoms
alone. In this SSR, we explain that CFS, when accompanied by appropriate medical signs or
laboratory findings, is an MDI that can be the basis for a finding of “disability.”
We also explain how we evaluate CFS claims.
CFS constitutes an MDI when accompanied by medical signs or laboratory findings, as
discussed below. CFS may be a disabling impairment. This policy interpretation clarifies
how our adjudicators should apply our regulations in determining whether a person
claiming benefits based on CFS is disabled under titles II and XVI of the Act. Adults
and children may claim these benefits. As mentioned, we include myalgic encephalomyelitis
(ME) as a subtype of CFS. When we refer to CFS in this SSR, we include ME.
I. What is CFS?
CFS is a systemic disorder that may vary in frequency, duration, and severity. CFS
can occur in children, particularly adolescents, as well as in adults.
The CDC and other medical experts characterize CFS, in part, as a syndrome that causes
prolonged fatigue lasting 6 months or more, resulting in a substantial reduction in
previous levels of occupational, educational, social, or personal activities. In accordance
with the CDC case definition of CFS, a physician should make a diagnosis of CFS “only
after alternative medical and psychiatric causes of chronic fatiguing illness have
A. General. Under the CDC case definition, the hallmark of CFS is the presence of clinically
evaluated, persistent, or relapsing chronic fatigue that:
1. Is of new or definite onset (that is, has not been lifelong);
2. Cannot be explained by another physical or mental disorder;
3. Is not the result of ongoing exertion;
4. Is not substantially alleviated by rest; and
5. Results in substantial reduction in previous levels of occupational, educational,
social, or personal activities.
B. Additional indications of CFS. CFS results in additional symptoms, some more common than others.
1. Diagnostic Symptoms. The CDC case definition requires the concurrence of 4 or more specific symptoms that
persisted or recurred during 6 or more consecutive months of illness and did not pre-date
Postexertional malaise lasting more than 24 hours (which may be the most common secondary
Self-reported impairment(s) in short-term memory or concentration severe enough to
cause substantial reduction in previous levels of occupational, educational, social,
or personal activities;
Tender cervical or axillary lymph nodes;
Multi-joint pain without joint swelling or redness;
Headaches of a new type, pattern, or severity; and
2. Other Symptoms. Within these parameters, the CDC case definition, CCC, and ICC describe a wide range
of other symptoms a person with CFS may exhibit:
Disturbed sleep patterns (for example, insomnia, prolonged sleeping, frequent awakenings,
or vivid dreams or nightmares);
Visual difficulties (for example, trouble focusing, impaired depth perception, severe
photosensitivity, or eye pain);
Orthostatic intolerance (for example, lightheadedness, fainting, dizziness, or increased
fatigue with prolonged standing);
Respiratory difficulties (for example, labored breathing or sudden breathlessness);
Cardiovascular abnormalities (for example, palpitations with or without cardiac arrhythmias);
Gastrointestinal discomfort (for example, nausea, bloating, or abdominal pain); and
Urinary or bladder problems (for example, urinary frequency, nocturia, dysuria, or
pain in the bladder region).
3. Co-occurring Conditions. People with CFS may have co-occurring conditions, such as fibromyalgia (FM), myofascial pain syndrome, temporomandibular joint syndrome, irritable bowel syndrome,
interstitial cystitis, Raynaud’s phenomenon, migraines, chronic lymphocytic thyroiditis, or Sjogren’s syndrome.
Co-occurring conditions may also include new allergies or sensitivities to foods,
odors, chemicals, medications, noise, vibrations, or touch, or the loss of thermostatic
stability (for example, chills, night sweats, or intolerance of extreme temperatures).
II. How does a person establish an MDI of CFS?
1. A person can establish that he or she has an MDI of CFS by providing appropriate
evidence from an acceptable medical source. A licensed physician (a medical or osteopathic doctor) is the only acceptable medical
source who can provide such evidence. We cannot rely upon the physician’s diagnosis
alone. The evidence must document that the physician reviewed the person’s medical
history and conducted a physical exam. We will review the physician’s treatment notes
to see if they are consistent with the diagnosis of CFS; determine whether the person’s
symptoms have improved, worsened, or remained stable; and establish the physician’s
assessment of the person’s physical strength and functional abilities.
2. We will find that a person has an MDI of CFS if a licensed physician diagnosed
CFS, and this diagnosis is not inconsistent with the other evidence in the person’s
case record. Under the CDC case definition, a physician can make the diagnosis of
CFS based on a person’s reported symptoms alone after ruling out other possible causes
for the person’s symptoms. However, as mentioned, 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 we may find that a person has an MDI of CFS. If we cannot find that
the person has an MDI of CFS but there is evidence of another MDI, we will not evaluate
the impairment under this SSR. Instead, we will evaluate it under the rules that apply
for that impairment.
B. Medical signs. For the 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
help establish the existence of an MDI of CFS:
Palpably swollen or tender lymph nodes on physical examination;
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. For example, the CCC
and ICC explain that an acute infectious inflammatory event may precede the onset
of CFS, and that other medical signs may be present, including the following:
Frequent viral infections with prolonged recovery;
Pronounced weight change.
C. Laboratory findings. At this time, we cannot identify specific laboratory findings that are widely accepted
as being associated with CFS. However, the absence of a definitive test does not preclude
our reliance upon certain laboratory findings to establish the existence of an MDI
in people with CFS. While standard laboratory test results in the normal range are
characteristic for many people with CFS, and they should not be relied upon to the
exclusion of all other clinical evidence in decisions regarding the presence and severity
of an MDI, the following laboratory findings establish the existence of an MDI in
people 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).
D. Additional signs and laboratory findings. Because of the ongoing research into the etiology and manifestations of CFS, the
medical criteria discussed above are only examples of physical and mental signs and
laboratory findings that can help us establish the existence of an MDI; they are not
all-inclusive. As medical research advances regarding CFS, we may discover additional
signs and laboratory findings to establish that people have an MDI of CFS. For example,
scientific studies now suggest there may be subsets of CFS with different causes,
including viruses such as Human Herpesvirus 6. Thus, we may document the existence
of CFS with medical signs and laboratory findings other than those listed above, provided
such evidence is consistent with medically accepted clinical practice and is consistent
with the other evidence in the case record.
E. Mental limitations. Some people with CFS report ongoing problems with short-term memory, information
processing, visual-spatial processing, 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 may constitute medical signs or (in the case
of psychological testing) laboratory findings that establish the presence of an MDI. When medical signs or laboratory findings suggest a persistent neurological impairment
or other mental problems, and these signs or findings are appropriately documented
in the medical record, we may find that the person has an MDI.
III. How do we document CFS?
A. General. In cases in which CFS is alleged, we generally need longitudinal evidence because
medical signs, symptoms, and laboratory findings of CFS fluctuate in frequency and
severity and often continue over a period of many months or years.
1. Longitudinal clinical records reflecting ongoing medical evaluation and treatment
from the person’s medical sources, especially treating sources, are extremely helpful
in documenting the presence of any medical signs or laboratory findings, as well as
the person’s functional status over time. The longitudinal record should contain detailed
medical observations, information about treatment, the person’s response to treatment,
and a detailed description of how the impairment limits the person’s ability to function.
2. In addition to obtaining evidence from a physician, we may request evidence from
other acceptable medical sources, such as psychologists, both to determine whether
the person has another MDI(s) and to evaluate the severity and functional effects
of CFS or any of the person’s other impairments. Under our regulations and SSR 06-03p,
we also may consider evidence from medical sources we do not consider “acceptable
medical sources” to help us evaluate the severity and functional effects of the impairment(s).
3. We may also consider information from nonmedical sources. This information may also help us assess the person’s ability to function day-to-day
and over time. It may also assist us in assessing the person’s allegations about symptoms
and their effects (see section IV below). Examples of nonmedical sources include:
Spouses, parents, siblings, other relatives, neighbors, friends, and clergy;
Past employers, rehabilitation counselors, and teachers; and
Statements from SSA personnel who interviewed the person.
4. Before we make a determination that you are not disabled, we will make every reasonable
effort to develop your complete medical history and help you get medical reports from
your own medical sources. Generally, we will request evidence from your medical sources
for the 12-month period preceding the month of application 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 application.
5. When the alleged onset of disability secondary to CFS occurred less than 12 months
before adjudication, we 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 the person’s treatment and response to treatment, as well as any
medical source opinions about the person’s prognosis at the end of 12 months, helps
us decide whether to expect the MDI to be of disabling severity for at least 12 consecutive
B. How do we consider medical opinions about a person’s impairment? We consider the nature of the treatment relationship between the medical source and the claimant when we evaluate the source’s medical opinions about a person’s
impairment(s). If we find that a treating source’s medical opinion regarding the nature
and severity of a person’s impairment(s) is well-supported by medically acceptable
clinical and laboratory diagnostic techniques, and the opinion is not inconsistent
with the other substantial evidence in the case record, we will give it controlling
weight. If a medical source states that a person is “disabled” or “unable to work,” or provides
an opinion on issues such as whether an impairment(s) meets or is equivalent in severity
to the requirements of a listing, a person’s residual functional capacity (RFC), or
the application of vocational factors, we consider these statements to be opinions
on issues reserved to the Commissioner. We must still consider such opinions in adjudicating
a disability claim; however, we will not give any special significance to such an
opinion because of its source.
C. Resolving conflicts. Conflicting evidence in the medical record is not unusual in cases of CFS due to
the complicated diagnostic process involved. We may seek clarification of any such
conflicts in the medical evidence first from the person’s treating or other medical
sources, in accordance with our rules.
D. What do we do if there is insufficient evidence to determine whether the person has
an MDI of CFS or is disabled?
1. When there is insufficient evidence for us to determine whether the person has
an MDI of CFS or is disabled, we may take one or more actions to try to resolve the
We may recontact the person’s treating or other source(s) to see if the information
we need is available;
We may request additional existing records;
We may ask the person or others for more information; or
We may purchase a consultative examination (CE) at our expense.
2. When we are unable to resolve an insufficiency in the evidence, and we need to
determine whether the person has an MDI of CFS or is disabled, we may make a determination
or decision based on the evidence we have.
IV. How do we evaluate a person’s statements about his or her symptoms and functional
Generally, we follow a two-step process:
A. First step of the symptom-evaluation process. There must be medical signs and findings that show the person has an MDI(s) which
we could reasonably expect to produce the fatigue or other symptoms alleged. If we find that a person has an MDI that we could reasonably expect to produce the
alleged symptoms, the first step of our two-step process for evaluating symptoms is
B. Second step of the symptom-evaluation process. After finding that the MDI could reasonably be expected to produce the alleged symptoms,
we evaluate the intensity and persistence of the person’s symptoms and determine the
extent to which they limit the person’s capacity for work. If objective medical evidence
does not substantiate the person’s statements about the intensity, persistence, and
functionally limiting effects of symptoms, we consider all of the evidence in the
case record, including the person’s daily activities; medications or other treatments
the person uses, or has used, to alleviate symptoms; the nature and frequency of the
person’s attempts to obtain medical treatment for symptoms; and statements by other
people about the person’s symptoms. We will evaluate the person’s statements regarding
the effects of his or her symptoms on functioning.  When we need additional information to evaluate the individual’s statements about
symptoms and their effects, we will make every reasonable effort to obtain available
information that could shed light on the person’s statements.
V. How do we find a person disabled based on an MDI of CFS?
Once we establish that a person has an MDI of CFS, we will consider this MDI in the
sequential evaluation process to determine whether the person is disabled. As we explain in section VI below, we consider the severity of the impairment, whether
the impairment medically equals the requirements of a listed impairment, and whether
the impairment prevents the person from doing his or her past relevant work or other
work that exists in significant numbers in the national economy.
VI. How do we consider CFS in the sequential evaluation process?
We adjudicate claims involving CFS using the sequential evaluation process, just as
we do for any impairment. Once we find that an MDI(s) exists (see section II), we
must establish the severity of the impairment(s). We determine the severity of a person’s
impairment(s) based on the totality of medical signs, symptoms, and laboratory findings,
and the effects of the impairment(s), including any related symptoms, on the person’s
ability to function. Additionally, several other disorders (including, but not limited
to FM, 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 person’s symptoms, it may be necessary to
pursue additional medical or other development. As mentioned, if we cannot find that
the person has an MDI of CFS but there is evidence of another MDI, we will not evaluate
the impairment under this SSR. Instead, we will evaluate it under the rules that apply
for that impairment.
A. Step 1. We consider the person’s work activity. If a person with CFS is doing substantial
gainful activity, we find that he or she is not disabled.
B. Step 2. If we establish that a person has an MDI that meets the duration requirement, and the person alleges fatigue, pain, symptoms of neurocognitive problems, or other
symptoms consistent with CFS, we must consider these symptoms in deciding whether
the person’s impairment is “severe” in step 2 of the sequential evaluation process,
and at any later steps reached in the sequential evaluation process. If we find fatigue,
pain, neurocognitive symptoms, or other symptoms cause a limitation or restriction,
and they have more than a minimal effect on a person’s ability to perform basic work
activities, we must find that the person has a “severe” impairment.
C. Step 3. When we find that a person has a severe MDI, we must proceed with the sequential
evaluation process and next consider whether the person’s impairment is of the severity
contemplated by the Listing of Impairments. CFS is not a listed impairment; therefore, we cannot find that a person with CFS
alone has an impairment that meets the requirements of a listed impairment. However,
we will compare the specific findings in each case to any pertinent listing (for example,
listing 14.06B in the listing for repeated manifestations of undifferentiated or mixed
connective tissue disease) to determine whether medical equivalence may exist. Further, in cases in which a person with CFS has psychological manifestations related
to CFS, we must consider whether the person’s impairment meets or equals the severity
of any impairment in the mental disorders listings.
D. Steps 4 and 5. For those impairments that do not meet or equal the severity of a listing, we must
make an assessment of the person’s RFC. After we make our RFC assessment, our evaluation
must proceed to the fourth step of the sequential evaluation process, if we do not
use an expedited process. If necessary, we then proceed to the fifth step of the sequential evaluation process. In assessing RFC, we must consider all of the person’s impairment-related symptoms
in deciding how such symptoms may affect functional capacities. The RFC assessment must be based on all the relevant evidence in the record. If we do not use an expedited process, we must determine that the person’s impairment(s)
precludes the performance of past relevant work (or if there was no past relevant
work). If we determine that the person’s impairment precludes performance of past
relevant work, we must make a finding about the person’s ability to perform other
work. We must apply the usual vocational considerations in determining the person’s ability
to perform other work.
E. Continuing disability reviews. In those cases in which we find that a person is disabled based on CFS, we will schedule
an appropriate continuing disability review. For this review, we take into account relevant individual case facts, such as the
combined severity of other chronic or static impairments and the person’s vocational
EFFECTIVE DATE: This Ruling is effective on April 3, 2014.
CROSS-REFERENCES: SSR 82-63: Titles II and XVI: Medical-Vocational Profiles Showing an Inability To
Make an Adjustment to Other Work; SSR 83-12: Title II and XVI: Capability To Do Other
Work—The Medical-Vocational Rules as a Framework for Evaluating Exertional Limitations
Within a Range of Work or Between Ranges of Work; SSR 83-14: Titles II and XVI: Capability
To Do Other Work—The Medical-Vocational Rules as a Framework for Evaluating a Combination
of Exertional and Nonexertional Impairments; SSR 85-15: Titles II and XVI: Capability
To Do Other Work—The Medical-Vocational Rules as a Framework for Evaluating Solely
Nonexertional Impairments; 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 16-3p,
Titles II and XVI: “Evaluation of Symptoms in Disability Claims;” SSR 96-8p, Titles
II and XVI: Assessing Residual Functional Capacity in Initial Claims; 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; SSR 02-2p, Titles II and XVI:
Evaluation of Interstitial Cystitis; SSR 06-03p, Titles II and XVI: Considering Opinions
and Other Evidence from Sources Who Are Not “Acceptable Medical Sources” in Disability
Claims; Considering Decisions on Disability by Other Governmental and Nongovernmental
Agencies; SSR 11-2p, Titles II and XVI: Documenting and Evaluating Disability in Young
Adults; SSR 12-2p, Titles II and XVI: Evaluation of Fibromyalgia; and Program Operations
Manual System (POMS) DI 22505.001, DI 22505.003, DI 24505.003, DI 24510.057, DI 24515.012, DI 24515.062 — DI 24515.063, DI 24515.075, DI 24555.001, DI 25010.001, and DI 25025.001.