National Coverage Determination (NCD)

PET (FDG) for Dementia and Neurodegenerative Diseases


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Tracking Information

Publication Number
Manual Section Number
Manual Section Title
PET (FDG) for Dementia and Neurodegenerative Diseases
Version Number
Effective Date of this Version
Ending Effective Date of this Version
Implementation Date
Implementation QR Modifier Date

Description Information

Benefit Category
Diagnostic Tests (other)

Please Note: This may not be an exhaustive list of all applicable Medicare benefit categories for this item or service.

Item/Service Description
Indications and Limitations of Coverage

A. General

Medicare covers FDG-PET scans for either the differential diagnosis of fronto-temporal dementia (FTD) and Alzheimer’s disease (AD) under specific requirements; OR, its use in a Centers for Medicare & Medicaid Services (CMS)-approved practical clinical trial focused on the utility of FDG-PET in the diagnosis or treatment of dementing neurodegenerative diseases. Specific requirements for each indication are clarified below:

B. Nationally Covered Indications

1.  FDG-PET Requirements for Coverage in the Differential Diagnosis of AD and FTD:

An FDG-PET scan is considered reasonable and necessary in patients with a recent diagnosis of dementia and documented cognitive decline of at least 6 months, who meet diagnostic criteria for both AD and FTD. These patients have been evaluated for specific alternate neurodegenerative diseases or other causative factors, but the cause of the clinical symptoms remains uncertain.

The following additional conditions must be met before an FDG-PET scan will be covered:

  1. The patient’s onset, clinical presentation, or course of cognitive impairment is such that FTD is suspected as an alternative neurodegenerative cause of the cognitive decline. Specifically, symptoms such as social disinhibition, awkwardness, difficulties with language, or loss of executive function are more prominent early in the course of FTD than the memory loss typical of AD;
  2. The patient has had a comprehensive clinical evaluation (as defined by the American Academy of Neurology (AAN)) encompassing a medical history from the patient and a well-acquainted informant (including assessment of activities of daily living), physical and mental status examination (including formal documentation of cognitive decline occurring over at least 6 months) aided by cognitive scales or neuropsychological testing, laboratory tests, and structural imaging such as magnetic resonance imaging (MRI) or computed tomography (CT);
  3. The evaluation of the patient has been conducted by a physician experienced in the diagnosis and assessment of dementia;
  4. The evaluation of the patient did not clearly determine a specific neurodegenerative disease or other cause for the clinical symptoms, and information available through FDG-PET is reasonably expected to help clarify the diagnosis between FTD and AD and help guide future treatment;
  5. The FDG-PET scan is performed in a facility that has all the accreditation necessary to operate nuclear medicine equipment. The reading of the scan should be done by an expert in nuclear medicine, radiology, neurology, or psychiatry, with experience interpreting such scans in the presence of dementia;
  6. A brain single photon emission computed tomography (SPECT) or FDG-PET scan has not been obtained for the same indication. (The indication can be considered to be different in patients who exhibit important changes in scope or severity of cognitive decline, and meet all other qualifying criteria listed above and below (including the judgment that the likely diagnosis remains uncertain). The results of a prior SPECT or FDG-PET scan must have been inconclusive or, in the case of SPECT, difficult to interpret due to immature or inadequate technology. In these instances, an FDG-PET scan may be covered after one year has passed from the time the first SPECT or FDG-PET scan was performed.)
  7. The referring and billing provider(s) have documented the appropriate evaluation of the Medicare beneficiary. Providers should establish the medical necessity of an FDG-PET scan by ensuring that the following information has been collected and is maintained in the beneficiary medical record:
    • Date of onset of symptoms;
    • Diagnosis of clinical syndrome (normal aging; mild cognitive impairment or MCI; mild, moderate or severe dementia);
    • Mini mental status exam (MMSE) or similar test score;
    • Presumptive cause (possible, probable, uncertain AD);
    • Any neuropsychological testing performed;
    • Results of any structural imaging (MRI or CT) performed;
    • Relevant laboratory tests (B12, thyroid hormone); and,
    • Number and name of prescribed medications.

    The billing provider must furnish a copy of the FDG-PET scan result for use by CMS and its contractors upon request. These verification requirements are consistent with federal requirements set forth in 42 Code of Federal Regulations section 410.32 generally for diagnostic x-ray tests, diagnostic laboratory tests, and other tests. In summary, section 410.32 requires the billing physician and the referring physician to maintain information in the medical record of each patient to demonstrate medical necessity [410.32(d) (2)] and submit the information demonstrating medical necessity to CMS and/or its agents upon request [410.32(d)(3)(I)] (OMB number 0938-0685).

2.  FDG-PET Requirements for Coverage in the Context of a CMS-approved Practical Clinical Trial Utilizing a Specific Protocol to Demonstrate the Utility of FDG-PET in the Diagnosis, and Treatment of Neurodegenerative Dementing Diseases

An FDG-PET scan is considered reasonable and necessary in patients with mild cognitive impairment or early dementia (in clinical circumstances other than those specified in subparagraph 1) only in the context of an approved clinical trial that contains patient safeguards and protections to ensure proper administration, use and evaluation of the FDG-PET scan.

The clinical trial must compare patients who do and do not receive an FDG-PET scan and have as its goal to monitor, evaluate, and improve clinical outcomes. In addition, it must meet the following basic criteria:

  1. Written protocol on file;
  2. Institutional Review Board review and approval;
  3. Scientific review and approval by two or more qualified individuals who are not part of the research team; and,
  4. Certification that investigators have not been disqualified.

C. Nationally Noncovered Indications

All other uses of FDG-PET for patients with a presumptive diagnosis of dementia-causing neurodegenerative disease (e.g., possible or probable AD, clinically typical FTD, dementia of Lewy bodies, or Creutzfeld-Jacob disease) for which CMS has not specifically indicated coverage continue to be noncovered.

D. Other

Not applicable.

(This NCD last reviewed September 2004.)

Cross Reference

See NCD for PET Scans (§220.6).

Transmittal Information

Transmittal Number
Revision History

04/2005 - Added "PET (FDG) for" to NCD title. Effective date 01/28/05. Implementation date 04/18/05. (TN 31) (CR 3741)

10/2004 - Covered use of FDG-PET Scans for differential diagnosis of fronto-temporal dementia and Alzheimer’s disease under specific requirements; OR its use in CMS-approved practical clinical trial focused on utility of FDG-PET in diagnosis or treatment of dementing neurodegenerative diseases. Effective date 09/15/2004. Implementation date 10/04/2004. (TN 24) (CR 3426)


National Coverage Analyses (NCAs)

This NCD has been or is currently being reviewed under the National Coverage Determination process. The following are existing associations with NCAs, from the National Coverage Analyses database.

Coding Analyses for Labs (CALs)

This NCD has been or is currently being reviewed under the National Coverage Determination process. The following are existing associations with CALs, from the Coding Analyses for Labs database.

Additional Information

Other Versions
Title Version Effective Between
FDG PET for Dementia and Neurodegenerative Diseases 3 04/03/2009 - N/A View
PET (FDG) for Dementia and Neurodegenerative Diseases 2 01/28/2005 - 04/03/2009 You are here
Dementia and Neurodegenerative Diseases 1 09/15/2004 - 01/28/2005 View
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Reasons for Denial
Note: This section has not been negotiated by the Negotiated RuleMaking Committee. It includes CMS’s interpretation of it’s longstanding policies and is included for informational purposes. Tests for screening purposes that are performed in the absense of signs, symptoms, complaints, or personal history of disease or injury are not covered except as explicity authorized by statue. These include exams required by insurance companies, business establishments, government agencies, or other third parties. Tests that are not reasonable and necessary for the diagnosis or treatment of an illness or injury are not covered according to the statue. Failure to provide documentation of the medical necessity of tests may result in denial of claims. The documentation may include notes documenting relevant signs, symptoms, or abnormal findings that substantiate the medical necessity for ordering the tests. In addition, failure to provide independent verification that the test was ordered by the treating physician (or qualified nonphysician practitioner) through documentation in the physician’s office may result in denial. A claim for a test for which there is a national coverage or local medical review policy will be denied as not reasonable and necessary if it is submitted without an ICD-9-CM code or narrative diagnosis listed as covered in the policy unless other medical documentation justifying the necessity is submitted with the claim. If a national or local policy identifies a frequency expectation, a claim for a test that exceeds that expectation may be denied as not reasonable and necessary, unless it is submitted with documentation justifying increased frequency. Tests that are not ordered by a treating physician or other qualified treating nonphysician practitioner acting within the scope of their license and in compliance with Medicare requirements will be denied as not reasonable and necessary. Failure of the laboratory performing the test to have the appropriate Clinical Laboratory Improvement Act of 1988 (CLIA) certificate for the testing performed will result in denial of claims.