CMS Retires NCD 220.6.20: What the End of Coverage with Evidence Development Means for Beta Amyloid PET Billing
CMS has officially retired the Coverage with Evidence Development (CED) requirement for beta amyloid PET imaging, a change that fundamentally shifts how Medicare coverage decisions are made for this diagnostic study. Under NCD 356 (Policy Key 356-v2), effective October 13, 2023, CMS removed NCD 220.6.20 and handed coverage determination authority to Medicare Administrative Contractors (MACs). If your facility bills for amyloid PET scans in dementia workups, this policy change affects your prior authorization process, your coverage expectations, and how you document medical necessity.
| Field | Detail |
|---|---|
| Payer | Centers for Medicare & Medicaid Services (CMS) |
| Policy | Beta Amyloid Positron Tomography in Dementia and Neurodegenerative Disease (RETIRED) |
| Policy Code | NCD 356 |
| Change Type | Modified |
| Effective Date | October 13, 2023 (formally documented March 12, 2026) |
| Impact Level | High |
| Specialties Affected | Neurology, Nuclear Medicine, Radiology, Geriatrics, Memory Care |
| Key Action | Contact your MAC immediately to confirm local coverage policies for amyloid PET imaging, as national CED requirements no longer apply. |
What Changed: CMS Removes the CED Requirement for Beta Amyloid PET Imaging
For years, Medicare coverage of beta amyloid PET scans — the imaging studies used to detect amyloid plaques associated with Alzheimer's disease and other neurodegenerative conditions — was locked behind a Coverage with Evidence Development requirement. That meant coverage was only available when the imaging was performed as part of an approved clinical trial or registry. For most clinical practices, that framework made routine Medicare reimbursement for amyloid PET essentially inaccessible.
That changed on October 13, 2023. CMS issued Transmittal 12364, removing NCD 220.6.20 entirely. With that NCD gone, CMS no longer imposes a national CED requirement on beta amyloid PET imaging. Coverage is now determined locally by each MAC under section 1862(a)(1)(A) of the Social Security Act — the standard "reasonable and necessary" medical necessity framework that governs most Medicare services.
This is a significant structural shift. The national policy is no longer the governing document. Your MAC's local coverage determination (LCD) — or the absence of one — now controls whether and how these studies are reimbursed.
Understanding the CED Model and Why Its Removal Matters for Revenue Cycle
CED coverage was designed for situations where CMS believed more evidence was needed before making a blanket national coverage decision. Under a CED framework, coverage was conditional: patients had to be enrolled in an approved study, and data had to be collected and submitted. For amyloid PET, this was tied to the Imaging Dementia — Evidence for Amyloid Scanning (IDEAS) study and subsequent registries.
The practical effect for billing teams was restrictive. Claims required specific registry documentation, coverage was limited to enrolled patients, and the billing pathway was narrow. Many practices simply did not pursue billing for these studies in the Medicare population.
With CED removed, that bottleneck is gone. But "removed CED" does not automatically mean "covered everywhere." It means coverage is now a MAC-by-MAC question, and the standard medical necessity rules apply.
How Medicare Coverage for Amyloid PET Works Now: MAC Jurisdiction
Under the revised policy framework, each MAC can do one of three things:
- Issue a new Local Coverage Determination (LCD) that establishes specific coverage criteria for amyloid PET in their jurisdiction
- Cover the service without an LCD under general medical necessity review, applying the reasonable and necessary standard
- Decline to cover the service if they determine it does not meet medical necessity requirements
This means that a neurologist in one state may have a clear, covered pathway for ordering amyloid PET for a Medicare patient with suspected Alzheimer's, while a colleague in a different MAC jurisdiction faces a non-coverage determination or pending LCD. Billing outcomes will vary by geography until MACs establish consistent local policies.
The CMS CED page (linked in the policy cross-reference) remains a resource for historical context and background on the amyloid PET evidence development process, but it is no longer the operative coverage document.
Prior Authorization and Medical Necessity Considerations for Amyloid PET
The NCD itself does not list prior authorization requirements — those will be dictated by individual MAC policies. What the billing and clinical teams need to focus on immediately is documentation. Because coverage is now evaluated under the general "reasonable and necessary" standard, the medical record must clearly support:
| # | Covered Indication |
|---|---|
| 1 | The specific clinical indication (e.g., evaluation of cognitive impairment, differential diagnosis between Alzheimer's disease and other causes of dementia) |
| 2 | Why the imaging is necessary for the individual patient's care plan |
| 3 | That standard diagnostic workup has been performed and is insufficient to establish a diagnosis |
Without the CED registry framework, there is no structured documentation pathway to follow. That shifts responsibility to the ordering physician and the billing team to build a compliant medical necessity case for each claim.
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
Affected Codes
The policy document for NCD 356 (Policy Key 356-v2) does not list specific CPT or HCPCS codes. No codes are enumerated in this NCD.
For billing purposes, amyloid PET imaging is typically reported using PET scan CPT codes. Your MAC's LCD or coverage article — if one has been issued in your jurisdiction — will specify the applicable codes and any diagnosis code requirements. Contact your MAC directly or review their coverage database to identify the exact codes they recognize for amyloid PET claims.
What Your Billing Team Should Do
| # | Action Item |
|---|---|
| 1 | Identify your MAC and check for an active LCD. Go to the CMS LCD database and search for amyloid PET or beta amyloid imaging under your jurisdiction. If your MAC has issued an LCD, pull the coverage criteria, covered codes, and any non-covered diagnoses now — before your next claim submission. |
| 2 | Reach out to your MAC's provider outreach and education team. If no LCD exists in your jurisdiction, ask the MAC directly how they are handling amyloid PET claims under the general medical necessity standard. Get that guidance in writing or documented via a provider bulletin. |
| 3 | Update your order templates and documentation requirements. Work with the ordering neurologists, geriatricians, and radiologists to ensure that clinical documentation explicitly addresses medical necessity for each amyloid PET order — the registry-based documentation pathway no longer applies, and standard claim review now governs. |
| 4 | Audit any outstanding or denied amyloid PET claims. If your facility has claims that were denied under the old CED framework after October 13, 2023, review them for potential appeal. The removal of NCD 220.6.20 effective that date may affect the basis for those denials. |
| 5 | Set a calendar review for Q3 2026. MAC LCD development takes time. Check back with your MAC's coverage database quarterly to catch any new LCDs for amyloid PET that establish formal coverage criteria in your jurisdiction. |
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