CPT code 82105 – Alpha-fetoprotein serum billing guide

Key takeaways

CPT code 82105 reports total AFP measured in serum. Amniotic fluid AFP uses 82106, and the AFP-L3 panel with total AFP uses 82107.

CMS NCD 190.25 limits Medicare coverage to monitoring AFP-producing tumors such as hepatocellular carcinoma, and average-risk screening is non-covered.

Missing or unsupported ICD-10 codes are the leading denial reason, so code the specific indication the ordering physician documented.

Practice management software like Pabau submits 82105 claims through Claim.MD, checks eligibility in real time, and tracks each claim through to the ERA.

CPT Code 82105: official descriptor and clinical overview

CPT Code 82105 is the AMA’s code for “Alpha-fetoprotein (AFP); serum.” It sits in the Chemistry subsection (82009-84999) of the Pathology and Laboratory chapter. The test measures the concentration of AFP in a blood specimen, using immunoassay, enzyme immunoassay, or electrochemiluminescence in a CLIA-certified laboratory.

AFP is a glycoprotein produced mainly by fetal liver cells and yolk sac tissue. In adults, raised serum AFP serves as a tumor marker. Two clinical contexts drive most 82105 orders:

• Tumor marker surveillance: Monitoring patients with known or suspected hepatocellular carcinoma (HCC), germ cell tumors (testicular, ovarian), or other AFP-producing malignancies
• Maternal serum screening: Prenatal assessment of neural tube defect risk, Down syndrome risk (in triple and quad screens), and other open fetal defects

CPT 82105 vs 82106 vs 82107: choosing the right AFP code

The most common coding error for AFP testing is picking the wrong code in the 82105-82107 family. Each code covers a distinct specimen or analyte, and payers deny a claim when the code doesn’t match the lab report. In short, 82105 is serum total AFP and 82106 is amniotic fluid AFP. The third code, 82107, is the AFP-L3 panel, which reports the L3 fraction, total AFP and their ratio.

82105 and 82107 are both serum tests, which causes most of the confusion. The difference is scope. 82105 reports total AFP on its own, while 82107 already includes total AFP alongside the L3 fraction and the ratio. So when the physician orders AFP-L3, report 82107 rather than adding 82105 for the same specimen. The diagram below maps each lab report scenario to its code.

Documentation requirements for CPT Code 82105 claims

A valid 82105 claim needs documentation that ties the lab result to a clinical indication. Missing documentation is a frequent denial trigger, second only to unsupported ICD-10 codes. The record must capture each of the following elements:

• Physician order: A signed order from the treating physician specifying serum AFP (not amniotic fluid or the AFP-L3 panel)
• Clinical indication: Documentation in the medical record showing why AFP monitoring is medically necessary for this patient (diagnosis, stage, surveillance interval)
• Specimen source: A lab report confirming the serum specimen type, since amniotic fluid specimens use 82106
• CLIA certification: A current CLIA certificate held by the performing laboratory, appropriate for the test complexity level
• ICD-10 code linkage: A diagnosis code on the claim that matches the indication in the ordering physician’s documentation, not merely the lab’s reason for testing

Prenatal screening claims need more. Many MACs require evidence of gestational age at the time of draw and the screening protocol used, such as a triple or quad screen. Follow-up AFP testing after an abnormal maternal screen is typically reported with O28.1. Keeping orders, requisitions and results together in the patient record protects the laboratory in an audit.

ICD-10 diagnosis codes that support medical necessity for CPT Code 82105

Payers accept only diagnosis codes that establish a clinical reason for measuring serum AFP. The CDC/NCHS ICD-10-CM tool provides the official code descriptions used in the table below. Always verify covered codes against the MAC LCD for your jurisdiction, as covered lists vary.

The CMS ICD-10 codes page publishes annual update files that reflect any changes to the covered diagnosis code lists. Coders should confirm that the ICD-10 code reflects the physician’s current documented indication, not a historical diagnosis carried forward from a prior visit.

Medicare coverage rules under NCD 190.25

CMS National Coverage Determination 190.25 is the primary Medicare policy governing alpha-fetoprotein testing. NCD 190.25 covers AFP serum testing ordered to monitor patients with known or suspected AFP-producing tumors, including hepatocellular carcinoma and germ cell tumors. Average-risk screening in patients without a documented clinical indication is explicitly non-covered under the NCD.

• Covered indications: Surveillance of HCC, monitoring of AFP-producing germ cell tumors (testicular, ovarian), and post-treatment follow-up for AFP-producing malignancies
• Non-covered indications: Population-level cancer screening with no documented personal history or active clinical suspicion, and routine health maintenance orders without a tumor marker indication
• Frequency limitations: NCD 190.25 sets no per-year frequency limit, but individual MAC LCDs often do. Typical limits run every one to three months during active treatment and every three to six months for surveillance. Verify your MAC’s LCD before submission.
• Prenatal screening: Maternal serum AFP for prenatal risk assessment falls under separate MAC LCD policies and state mandates. NCD 190.25 does not address prenatal use directly.

In practice, an AFP order with no documented tumor history or active oncology indication should not go to Medicare as a covered service. Where coverage is doubtful, the lab can issue an Advance Beneficiary Notice (ABN) before the draw, so the patient can accept financial responsibility.

CPT Code 82105 fee schedule and reimbursement rates (2025-2026)

CPT Code 82105 is paid under the Medicare Clinical Laboratory Fee Schedule (CLFS), not the Physician Fee Schedule. The CLFS pays a single national rate, while the Physician Fee Schedule applies geographic adjustments. Rates change every year, so confirm the figures below against the CMS CLFS file before submitting claims.

Commercial payers set their own contract rates, which may sit above or below the CLFS rate. Payers with CLFS-based contracts typically pay at or near 100% of the CLFS rate, while others negotiate separately. Electronic submission to Medicare and most commercial payers uses the 837 electronic claim file. Reconcile each 82105 payment against the electronic remittance advice (ERA) to catch underpayments early.

Billing CPT 82105 alongside other tumor marker codes

Oncology practices and reference laboratories often order AFP alongside other tumor marker assays on the same date of service. CPT Code 82105 can generally be billed with the following codes when the clinical record documents a distinct indication for each marker:

• CPT 82378 (CEA): Carcinoembryonic antigen, commonly ordered alongside AFP for GI malignancy surveillance. No NCCI bundle applies between 82105 and 82378.
• CPT 86304 (CA 125): Often ordered with AFP for ovarian malignancy monitoring. Verify NCCI edits for the specific combination.
• CPT 86301 (CA 19-9): Pancreatic and GI tumor marker that may accompany AFP in hepatobiliary tumor workups.
• CPT 82107 (AFP-L3): Already includes total AFP and the ratio, so adding 82105 for the same specimen duplicates the total AFP result. Check current NCCI edits before billing the pair.

Panel billing requires a documented clinical indication for each code in the panel. Bundling multiple tumor markers without distinct per-test documentation is a common audit finding. On a denied same-day claim, the ERA usually carries a claim adjustment reason code (CARC). It shows which code was treated as bundled or not separately payable.

Common denial reasons for CPT 82105 claims and how to prevent them

Most 82105 denials are preventable with the right pre-submission checks. The medical billing denial codes that appear most often on AFP claims fall into five categories:

A denial management workflow for lab claims starts before submission. Check the ICD-10 code, the specimen type and the MAC frequency limit against the order before the claim goes out. Claims management software then handles submission and tracking, so each denial comes back with a reason code your team can act on. A clean claim on the first pass is the single highest-leverage way to cut 82105 denials.

How Pabau keeps 82105 lab claims moving

Many practices still key an AFP order into one system and the claim into another. Each re-key is another chance for the specimen type or the diagnosis code to drift from what the physician documented.

Practice management software like Pabau keeps the signed order, the lab result and the claim on the same patient record. Through its Claim.MD integration, Pabau submits the CMS-1500 claim electronically, runs a real-time eligibility check, and tracks the claim’s status.

When the payer responds, the ERA comes back into Pabau. Your team can reconcile the payment against the CLFS rate or work the denial straight away, while coding decisions stay with your coders.

Submit and track lab claims in one place

Pabau’s Claim.MD integration submits CMS-1500 claims, checks eligibility in real time, and tracks each claim to the ERA. See how it fits your lab billing workflow.

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Conclusion

Two checks settle most 82105 claims before they go out. Confirm the specimen was serum and the order asked for total AFP, not the AFP-L3 panel. Then match the ICD-10 code to the indication the physician documented, not the lab’s reason for testing.

For Medicare patients, NCD 190.25 draws the line at tumor monitoring. Average-risk screening needs an ABN before the draw, not an appeal afterward. That costs a little more work at the order stage and saves far more time chasing denials later.

Book a demo to see how Pabau submits and tracks your lab claims, so your team spends less time working denials.

Continue your research

Need a framework for managing lab claim denials? Denial management in healthcare walks through systematic approaches to tracking, appealing, and preventing recurring claim denials.

How does electronic remittance advice work for lab payments? Electronic remittance advice (ERA) explains how 835 transaction sets communicate payment decisions and CARC reason codes back to the billing team.

Looking for the broader billing compliance context? Medical billing compliance covers documentation retention, audit risk management, and the regulatory framework labs need to maintain.

Want fewer AFP claims coming back? Clean claims in medical billing covers the checks that get a lab claim paid on the first submission.

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