TL;DR: The Centers for Medicare & Medicaid Services modified NCD 336 governing PET NaF-18 coverage policy, with a policy update recorded February 19, 2026. The bottom line hasn't changed since December 2017 — PET NaF-18 for bone metastasis detection is nationally non-covered under Medicare — but billing teams need to understand exactly what this means before submitting claims.
| Field | Detail |
|---|---|
| Payer | CMS |
| Policy | Positron Emission Tomography (NaF-18) to Identify Bone Metastasis of Cancer |
| Policy Code | NCD 336 |
| Change Type | Modified |
| Effective Date | 2026-02-19 |
| Impact Level | High |
| Specialties Affected | Nuclear medicine, radiology, oncology, radiation oncology |
| Key Action | Do not bill Medicare for PET NaF-18 bone metastasis imaging — check MAC policy for other PET radiopharmaceutical tracers |
CMS PET NaF-18 Coverage Criteria and Medical Necessity Requirements 2026
Here's the situation: there are no nationally covered indications for PET NaF-18 under Medicare. None. CMS made that call effective December 15, 2017, after confirmatory analyses required under Coverage with Evidence Development (CED) were not published within the 24-month window.
NCD 336 is the National Coverage Determination governing Medicare coverage of PET scans using F-18 sodium fluoride (NaF-18) to identify bone metastasis in cancer patients. The CMS PET NaF-18 coverage policy is unambiguous: this is a nationally non-covered service. Medical necessity arguments will not save these claims at the national level.
This matters because oncology and nuclear medicine billing teams still occasionally submit these claims — sometimes because a physician believes the scan is clinically justified, sometimes because a facility inherited old charge capture templates. Neither reason changes the reimbursement outcome. Medicare will deny them.
Prior authorization is irrelevant here. You can't get prior authorization for a service with no nationally covered indications. If your team is even asking whether prior auth applies, that's a signal your charge capture or pre-service workflows need attention.
The one door left open is Section D of NCD 336. Other PET radiopharmaceutical tracers — not NaF-18, but other agents used for cancer imaging — can be covered at local Medicare Administrative Contractor (MAC) discretion. Coverage depends on whether those tracers are used according to their FDA-approved indications. That's a local coverage determination (LCD) question, not a national one.
CMS PET NaF-18 Exclusions and Non-Covered Indications
PET NaF-18 is nationally non-covered for all indications under Medicare. This isn't a situation where some diagnoses qualify and others don't. CMS drew a hard line.
The backstory: NaF-18 PET scans were previously reviewed under Coverage with Evidence Development. CED is CMS's mechanism for covering promising but unproven technologies while evidence is gathered. The deal was that confirmatory analyses would be published within 24 months. They weren't. CMS responded by pulling coverage entirely, effective December 15, 2017.
That decision stands. The February 19, 2026 policy update does not reinstate coverage. It does not add exceptions. If you were hoping this modification reopened the door, it didn't.
The real exposure here is billing teams that don't have this non-coverage status flagged in their systems. A claim that goes out the door for PET NaF-18 bone metastasis imaging under Medicare will generate a claim denial. That denial costs time, creates accounts receivable drag, and — if it's happening repeatedly — raises compliance flags you don't want.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| PET NaF-18 to identify bone metastasis of cancer | Not Covered | None listed in NCD 336 | Nationally non-covered effective December 15, 2017. No medical necessity exception available at national level. |
| Other PET radiopharmaceutical tracers for cancer | MAC Discretion | Not specified in NCD 336 | Coverage available when used per FDA-approved indications. Check your MAC's LCD. |
CMS PET NaF-18 Billing Guidelines and Action Items 2026
This is where most billing teams drop the ball — they know a service is non-covered but don't close the loop on the operational side. Here's what to do now.
| # | Action Item |
|---|---|
| 1 | Audit your charge capture for PET NaF-18 immediately. If your nuclear medicine or radiology charge templates include any PET NaF-18 bone metastasis scan codes, flag them. Add a hard stop or a billing alert that prevents these charges from flowing to Medicare claims without a review. |
| 2 | Confirm your claim denial tracking includes NCD 336. If you're seeing Medicare denials for PET NaF-18, they should be caught, categorized, and escalated — not just written off. Repeated denials on a nationally non-covered service can attract attention from your MAC's post-payment review team. |
| 3 | Review any Advance Beneficiary Notices (ABNs) in your workflow. For non-covered services, an ABN shifts financial liability to the patient. If your team is performing PET NaF-18 scans that patients are paying for out of pocket, make sure your ABN process is airtight and documented before services are rendered. |
| 4 | Check your MAC's LCD for other PET tracers. NCD 336 explicitly carves out local coverage determination discretion for other PET radiopharmaceutical agents used in cancer imaging. If your facility uses FDG-PET or other FDA-approved tracers, contact your MAC or check their published LCDs to confirm coverage status and billing guidelines for those services. |
| 5 | Brief your ordering physicians on NaF-18 reimbursement status. If nuclear medicine physicians or oncologists at your facility are still ordering NaF-18 PET scans expecting Medicare coverage, they need to know the reimbursement reality. This is a conversation between your billing team and your medical director — not just a memo. The physician order drives the claim; the physician needs to understand what CMS will and won't pay. |
| 6 | If your facility has a research protocol involving NaF-18 PET, talk to your compliance officer before any Medicare claims touch those services. The CED framework that originally allowed limited coverage is closed, but research billing has its own rules. Don't assume anything. |
| 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 |
CPT, HCPCS, and ICD-10 Codes for PET NaF-18 Under NCD 336
Important Note on Codes
NCD 336 does not list specific CPT or HCPCS codes in its current form. The policy text addresses the NaF-18 radiopharmaceutical and the PET imaging procedure broadly, without attaching specific procedure codes. This is not unusual for older NCDs — CMS published NCD 336 before code-level specificity became standard practice in coverage determinations.
This creates a practical problem for PET NaF-18 billing teams. Without CMS-listed codes in the NCD itself, you need to confirm which codes your MAC associates with this non-covered service. Contact your MAC's provider relations line or check their website for guidance on how to report NaF-18 PET scans and how to apply the non-coverage status in your claims.
Do not fabricate code associations based on what seems logical. The wrong modifier or the wrong code combination can turn a clean denial into a billing compliance issue.
What This Means for Your Claims
The absence of specific codes in NCD 336 does not create a loophole. The national non-coverage determination applies to the service — PET NaF-18 for bone metastasis detection — regardless of which procedure code is attached. CMS and your MAC will apply the NCD at the service level, not the code level.
If you're unsure which codes your MAC is tracking against NCD 336, that question belongs on your compliance officer's desk before February 19, 2026, not after.
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