Lab & pathology
87340 — Infectious agent antigen detection; hepatitis B surface antigen
A blood test using an immunoassay (such as ELISA) to detect the hepatitis B surface antigen, a protein on the surface of the hepatitis B virus, to determine if someone is currently infected with hepatitis B.
- Typical setting: Hospital lab, reference lab
- National avg charge (illustrative): $10–$22 Medicare allowed (CMS CLFS); $15–$60 commercial; varies by region
- Most-disputed reason: Billing 87340 when already included in the obstetric panel (80055) on the same date — bundling rules prohibit separate billing of included components
What it means
What 87340 actually means
A blood test using an immunoassay (such as ELISA) to detect the hepatitis B surface antigen, a protein on the surface of the hepatitis B virus, to determine if someone is currently infected with hepatitis B. A positive result means the person is actively infected and potentially contagious.
Common errors with this code
What goes wrong on real bills.
Most bills that look correct still contain at least one of these issues. Up to 49% of medical bills contain errors (CFPB).
- Billing 87340 when already included in the obstetric panel (80055) on the same date — bundling rules prohibit separate billing of included components
- Confusing 87340 (surface antigen) with 86704 (core antibody IgM), 86706 (surface antibody), or 86709 (core antibody total) — each hepatitis B marker has a separate code
- Medical necessity denials when billing 87340 without an appropriate ICD-10 diagnosis or exposure/screening indication
If you see 87340 on your bill
Three steps before paying.
1. Get the itemized bill. If your statement only shows a summary, request the CPT-level itemized bill before paying. Generate the request language →
2. Cross-check against the EOB. Compare what your insurer's Explanation of Benefits says you owe versus what the hospital is asking. They disagree more often than people think. Read the bill-vs-EOB guide →
3. Run a free Bill Scan. Upload the bill (and EOB if you have it) and BillBusted will flag the most likely issues with this specific code in your specific state. Run free scan →
Related codes
Other codes in this category.
People who land on 87340 often also see these adjacent codes on the same bill.
CPT
80050 — General health panel; includes CBC w/diff, CMP, TSH
Lab — check for unbundling and duplicate billing.
CPT
80051 — Electrolyte panel; CO2, chloride, potassium, sodium
Lab — check for unbundling and duplicate billing.
CPT
80053 — Comprehensive metabolic panel
If individual blood tests are also on your bill, you may have an unbundling error.
CPT
80055 — Obstetric panel; CBC w/diff, HBsAg, rubella Ab, syphilis, RBC Ab screen, ABO/Rh
Lab — check for unbundling and duplicate billing.
CPT
80061 — Lipid panel (cholesterol)
If you see HDL or LDL listed separately next to 80061, that's unbundling.
Related BillBusted guides
Plain-English reads if you see 87340 on a bill.
87340 FAQ
Plain-English answers.
What does 87340 usually cost?
$10–$22 Medicare allowed (CMS CLFS); $15–$60 commercial; varies by region. Costs vary by region, payer contract, and whether the service was performed in a hospital outpatient department (which adds a facility fee) versus a free-standing clinic.
What's the most common billing error on 87340?
Billing 87340 when already included in the obstetric panel (80055) on the same date — bundling rules prohibit separate billing of included components
What should I do if I see 87340 on my bill?
Request the itemized bill and the matching EOB from your insurer. Compare the units/quantity billed against what you actually received. Run a free BillBusted scan to flag the most likely errors specific to 87340 before paying.
Don't pay 87340 blindly.
The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.