CMS Modified NCD 121 for Alpha-Fetoprotein Coverage, Effective March 7, 2026 — What Billing Teams Need to Know
TL;DR: The Centers for Medicare & Medicaid Services modified NCD 121, the National Coverage Determination governing Medicare alpha-fetoprotein (AFP) testing, effective March 7, 2026. Here's what changes for billing teams.
This update to the CMS AFP coverage policy codifies which clinical indications support medical necessity for AFP as a diagnostic laboratory test. The policy does not list specific CPT or HCPCS codes directly — you'll need to cross-reference the quarterly Covered Code Lists linked through CMS's claims processing instructions. If your lab or practice bills AFP testing for hepatocellular carcinoma monitoring or germ cell tumor workup, read this before the effective date of March 7, 2026.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Alpha-fetoprotein — NCD 121 |
| Policy Code | NCD 121 in the Medicare NCD system |
| Change Type | Modified |
| Effective Date | March 7, 2026 |
| Impact Level | Medium |
| Specialties Affected | Clinical laboratory, oncology, hepatology, urology, gynecologic oncology |
| Key Action | Pull the current quarterly Covered Code List from CMS and confirm your AFP billing codes map correctly to covered indications before submitting claims after March 7, 2026 |
CMS Alpha-Fetoprotein Coverage Criteria and Medical Necessity Requirements 2026
NCD 121 is the National Coverage Determination governing Medicare coverage of alpha-fetoprotein testing as a diagnostic laboratory service. AFP is a polysaccharide that functions as a biochemical tumor marker. CMS covers it in two distinct clinical roles — and your claim denial risk hinges on which role you're documenting.
Role 1: Hepatocellular Carcinoma
The first covered use is AFP for hepatocellular carcinoma (HCC) in high-risk patients. CMS defines "high-risk" specifically. It includes patients with alcoholic cirrhosis, cirrhosis of viral etiology, hemochromatosis, and alpha-1-antitrypsin deficiency.
The coverage policy also covers AFP to differentiate between benign hepatocellular neoplasms or metastatic disease and true hepatocellular carcinoma. This is a meaningful distinction for billing. The test must serve a diagnostic or monitoring purpose — not a routine screening function — to support medical necessity.
If your documentation doesn't tie AFP ordering to one of these specific high-risk conditions, you're billing into claim denial territory. The policy is not ambiguous here. The clinical rationale must match the covered indications, and your progress notes need to reflect that connection.
Role 2: Germ Cell Neoplasms
The second covered use is AFP as a non-specific tumor-associated antigen for marking germ cell neoplasms. The policy names four anatomical sites: testis, ovary, retroperitoneum, and mediastinum.
This is broader than many billing teams assume. The policy covers AFP in the germ cell context regardless of whether the ordering clinician is a urologist, gynecologic oncologist, or thoracic surgeon. What ties the claim together is documentation of the germ cell neoplasm and the clinical rationale for using AFP as the marker.
Monitoring vs. Diagnosis
AFP billing guidelines under NCD 121 make no explicit distinction between initial diagnosis and ongoing monitoring. The policy language says AFP "is effective as a biochemical marker for monitoring the response of certain malignancies to therapy." That phrase matters.
It means a reimbursement pathway exists for serial AFP testing during active treatment — but your documentation must reflect the monitoring purpose. Ordering AFP every cycle because it's in the protocol isn't enough. The note needs to show the clinician is using AFP results to assess treatment response.
Prior authorization is not explicitly required under this NCD. However, Medicare Administrative Contractors may apply local coverage determination rules on top of this national policy. Check with your MAC before assuming prior authorization is off the table for all AFP claims in your region.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| AFP for HCC diagnosis in patients with alcoholic cirrhosis | Covered | See quarterly Covered Code List | High-risk condition must be documented |
| AFP for HCC diagnosis in patients with viral cirrhosis | Covered | See quarterly Covered Code List | Viral etiology must be specified in documentation |
| AFP for HCC diagnosis in patients with hemochromatosis | Covered | See quarterly Covered Code List | High-risk condition must be documented |
| AFP for HCC diagnosis in patients with alpha-1-antitrypsin deficiency | Covered | See quarterly Covered Code List | High-risk condition must be documented |
| AFP to differentiate benign hepatocellular neoplasm or metastases from HCC | Covered | See quarterly Covered Code List | Diagnostic distinction must be the stated clinical purpose |
| AFP as tumor marker for testicular germ cell neoplasms | Covered | See quarterly Covered Code List | Order must reference germ cell neoplasm |
| AFP as tumor marker for ovarian germ cell neoplasms | Covered | See quarterly Covered Code List | Order must reference germ cell neoplasm |
| AFP as tumor marker for retroperitoneal germ cell neoplasms | Covered | See quarterly Covered Code List | Order must reference germ cell neoplasm |
| AFP as tumor marker for mediastinal germ cell neoplasms | Covered | See quarterly Covered Code List | Order must reference germ cell neoplasm |
| AFP for monitoring treatment response in covered malignancies | Covered | See quarterly Covered Code List | Documentation must reflect monitoring purpose |
| AFP for general cancer screening without covered indication | Not Covered | N/A | No high-risk condition or germ cell neoplasm documented |
CMS Alpha-Fetoprotein Billing Guidelines and Action Items 2026
Here's what your billing team needs to do before and after March 7, 2026.
1. Pull the current quarterly Covered Code List now.
NCD 121 does not embed specific CPT or HCPCS codes in the policy document itself. CMS maintains quarterly Covered Code Lists for clinical laboratory services. Go to the CMS Clinical Laboratory Fee Schedule resources and download the current list. Confirm which AFP-related codes are active for the quarter covering March 7, 2026. Don't rely on a code list from last quarter — these lists change.
2. Audit your documentation templates for AFP orders.
Every covered indication under NCD 121 requires a specific clinical rationale. Review your EHR order sets and lab requisition templates. If AFP ordering doesn't prompt the clinician to document the underlying high-risk condition or germ cell neoplasm, fix that before the effective date. A missing indication in the order is a medical necessity problem at audit.
3. Train your coding staff on the two AFP use cases.
AFP for hepatocellular carcinoma workup and AFP for germ cell tumor marking are different clinical contexts. Your coders need to recognize which context they're looking at and confirm that the documentation supports it. This is not a place for assumptions. If the note doesn't specify the indication, query the provider before billing.
4. Check your MAC's local coverage determination.
NCD 121 is a national policy, but your Medicare Administrative Contractor may have an LCD that adds requirements on top of it — including prior authorization, frequency limits, or additional documentation criteria. Search your MAC's LCD database by procedure category. If an LCD exists for AFP testing in your jurisdiction, that LCD governs alongside NCD 121.
5. Review serial AFP claims for monitoring documentation.
If your practice bills AFP repeatedly during active cancer treatment, each claim needs documentation showing the test is monitoring treatment response — not just being ordered reflexively. Pull a sample of recent serial AFP claims. Check that the ordering note references AFP results in the context of assessing therapy efficacy. If it doesn't, that's a denial and a potential overpayment risk.
6. Update your charge capture for AFP to flag unsupported indications.
Build a charge capture rule that flags AFP claims where the documented diagnosis doesn't match a covered indication. This catches the problem before the claim goes out. Claim denial for AFP under NCD 121 is almost always a documentation mismatch — and most of those are preventable at charge entry.
If you're unsure how NCD 121 interacts with your payer mix or your MAC's LCD, talk to your compliance officer before the effective date. The covered indications are narrow enough that a systematic documentation problem could generate significant overpayment exposure across a high-volume AFP billing program.
| 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 Alpha-Fetoprotein Under NCD 121
Covered Codes
NCD 121 in the Medicare system does not list specific CPT or HCPCS codes within the policy document. CMS directs billers to the quarterly Covered Code Lists for clinical laboratory services, updated each quarter and published alongside the Clinical Laboratory Fee Schedule.
Action: Go to the CMS website and download the current quarterly Covered Code List for clinical laboratory services. Search for AFP or alpha-fetoprotein to identify the active billing codes covered under this NCD. The quarterly list is the authoritative source — not this policy document, and not last year's fee schedule.
A Note on Code Sourcing for AFP Billing
This is worth saying plainly: alpha-fetoprotein billing codes exist and are widely billed. The policy itself simply doesn't enumerate them in the NCD document. CMS routes code-level detail through the Claims Processing Manual (Chapter 120, Clinical Laboratory Services Based on Negotiated Rulemaking) and the quarterly Covered Code Lists.
If your billing software maps AFP codes to NCD 121 automatically, verify that the mapping reflects the current quarterly list. Software vendors don't always update these mappings on the same schedule CMS does.
ICD-10-CM Diagnosis Codes
NCD 121 does not specify ICD-10-CM codes. Base your diagnosis coding on the documented clinical indication:
- Hepatocellular carcinoma with documented high-risk etiology (alcoholic cirrhosis, viral cirrhosis, hemochromatosis, alpha-1-antitrypsin deficiency)
- Germ cell neoplasms of the testis, ovary, retroperitoneum, or mediastinum
Your ICD-10-CM code must reflect the specific condition, not just "malignancy" or "neoplasm." The more precise your diagnosis code, the stronger your medical necessity support. Vague diagnosis coding is one of the top drivers of AFP claim denial under this coverage policy.
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