CMS PET NaF-18 Bone Metastasis Coverage Policy Update (NCD 336): What Billing Teams Need to Know in 2026
The Centers for Medicare & Medicaid Services (CMS) has issued a modified update to National Coverage Determination (NCD) 336, which governs coverage of Positron Emission Tomography using sodium fluoride (PET NaF-18) for identifying bone metastasis of cancer. The core finding hasn't changed since December 2017—PET NaF-18 remains nationally non-covered under Medicare—but this 2026 modification makes it critical for billing teams to confirm their claims workflows, denial management protocols, and local coverage strategies are current and correctly configured.
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Positron Emission Tomography (NaF-18) to Identify Bone Metastasis of Cancer |
| Policy Code | NCD 336 (Policy Key: 336-v2) |
| Change Type | Modified |
| Effective Date | 2026-03-12 |
| Impact Level | High |
| Specialties Affected | Nuclear Medicine, Oncology, Radiology, Radiation Oncology |
| Key Action | Confirm your practice is not submitting Medicare claims for PET NaF-18 and verify whether a local MAC policy applies to your jurisdiction. |
What NCD 336 Says: CMS Coverage Status for PET NaF-18
PET NaF-18 is a diagnostic imaging procedure that uses F-18 sodium fluoride as a radiopharmaceutical tracer to assess metabolic activity and perfusion in bone tissue. It produces cross-sectional tomographic images that can, in theory, identify areas of elevated bone turnover consistent with metastatic cancer.
The problem: CMS determined in 2017 that the confirmatory analyses required to establish a nationally covered indication under the Coverage with Evidence Development (CED) framework were never published within the required 24-month window. That failure to produce confirmatory data triggered a definitive non-coverage determination.
Here's where NCD 336 currently stands as of the 2026 modification:
- Nationally Covered Indications: None. CMS has determined there are no nationally covered indications for PET NaF-18, effective December 15, 2017.
- Nationally Non-Covered Indications: PET NaF-18 is nationally non-covered for Medicare beneficiaries. Full stop.
- No prior authorization pathway: Because there are no covered indications at the national level, this isn't a prior authorization issue—it's a coverage exclusion. Submitting claims expecting prior authorization to unlock coverage will not work.
This is a hard national non-coverage determination, not a "coverage with conditions" or a "frequency limitation" scenario. That distinction matters significantly for how your billing team codes and appeals these cases.
Why This Matters in 2026: The MAC Discretion Exception
The one area of genuine nuance in NCD 336—and the one your billing team needs to understand thoroughly—is the exception for other PET radiopharmaceutical tracers.
According to the policy, other PET radiopharmaceutical tracers for cancer (not NaF-18 specifically) can be covered at local Medicare Administrative Contractor (MAC) discretion when used according to their FDA-approved indications. This is not a workaround for NaF-18, but it is important context for practices that perform multiple types of PET imaging.
If your facility images bone metastasis using alternative FDA-approved PET tracers, you are operating under a different coverage framework—one governed by your regional MAC's Local Coverage Determination (LCD), not NCD 336. Conflating these two coverage pathways is a billing risk.
To find your MAC's applicable LCD for alternative PET tracers, visit the CMS CED page cross-referenced in NCD 336 and your MAC's specific LCD database.
The CED History Behind This Non-Coverage Determination
Understanding why CMS reached this conclusion is useful for any billing team fielding questions from clinicians or compliance staff.
CMS originally covered PET NaF-18 on a Coverage with Evidence Development (CED) basis, meaning coverage was contingent on facilities participating in data collection registries designed to generate real-world evidence. CED coverage is CMS's mechanism for allowing access to promising technologies while building the evidence base needed for full national coverage.
In the case of NaF-18, the required confirmatory analyses—the evidence that would have supported converting CED coverage to full national coverage—were not published within the 24-month window CMS established. As a result, CMS exercised its authority to terminate coverage. There is no active CED registry for PET NaF-18 at this time.
For practices that had previously been submitting claims under the CED framework, this history is a reminder to audit your claim history and confirm no legacy workflows are still routing NaF-18 cases through Medicare.
| 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 336 (336-v2) does not list specific CPT or HCPCS codes. CMS has not included applicable billing codes within this NCD.
What this means for your billing team: You will need to identify the HCPCS code applicable to your NaF-18 studies (historically A9580 has been associated with sodium fluoride F-18 injection, but confirm current code applicability with your MAC and coding resources) and ensure those claims are not being submitted to Medicare. The absence of codes within the NCD itself is not an opening—the non-coverage language is definitive.
Related ICD-10 context: While NCD 336 does not enumerate specific diagnosis codes, the clinical context involves bone metastasis diagnoses (C79.51, C79.52, and related secondary malignant neoplasm codes). Claims for PET NaF-18 submitted under these diagnosis codes will be denied under this NCD regardless of the diagnosis.
What Your Billing Team Should Do
| # | Action Item |
|---|---|
| 1 | Audit your charge master and order entry system immediately (by April 1, 2026). Confirm that PET NaF-18 studies are flagged as non-covered for Medicare patients at the point of order entry—before the scan occurs. A non-coverage determination this definitive should trigger an Advance Beneficiary Notice (ABN) workflow for any Medicare patient whose physician still orders this study. |
| 2 | Issue an ABN before performing PET NaF-18 on Medicare beneficiaries. Because this service is nationally non-covered, an ABN (CMS Form CMS-R-131) should be presented to the patient before the service is rendered if the facility intends to bill the patient directly. Without a valid ABN, you cannot collect payment from the patient for a denied Medicare service. |
| 3 | Audit the last 12 months of claims for any PET NaF-18 submissions billed to Medicare. If your facility has submitted claims for this service and received payment, you may have a repayment obligation. Consult your compliance officer and consider a voluntary self-disclosure if inappropriate payments were received. |
| 4 | Contact your MAC if you use alternative PET tracers for bone metastasis imaging. Confirm which FDA-approved PET radiopharmaceuticals your MAC covers under LCD, what documentation requirements apply, and whether prior authorization or clinical documentation of medical necessity is required. Do not assume NCD 336's non-coverage extends to all bone PET imaging. |
| 5 | Educate your ordering oncologists and nuclear medicine physicians. Clinicians may be unaware that Medicare coverage for NaF-18 lapsed in 2017. A brief internal communication referencing NCD 336 and the ABN requirement can prevent both claims denials and compliance issues. |
Affected Codes
As noted above, the CMS policy document for NCD 336 (336-v2) does not list specific CPT or HCPCS codes. No codes are included in this policy's data.
| Code Listing | Status |
|---|---|
| CPT/HCPCS codes | Not enumerated in NCD 336 |
| ICD-10-CM codes | Not enumerated in NCD 336 |
Verify applicable billing codes with your MAC, your coding reference tools, and your nuclear medicine billing specialist before submitting or suppressing claims.
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