Lab & pathology

86618 — Antibody; Borrelia burgdorferi immunoassay

A blood test using an immunoassay (ELISA) to look for antibodies to Borrelia burgdorferi, the bacteria that causes Lyme disease, in blood or cerebrospinal fluid.

  • Typical setting: Hospital lab, reference lab
  • National avg charge (illustrative): $15–$35 Medicare allowed (CMS CLFS); $25–$100 commercial; varies by region
  • Most-disputed reason: Billing 86618 (Lyme immunoassay/ELISA) and 86617 (Lyme antibody confirmation) together without documentation that both tiers were ordered — two-tier testing is appropriate, but both must be documented

What it means

What 86618 actually means

A blood test using an immunoassay (ELISA) to look for antibodies to Borrelia burgdorferi, the bacteria that causes Lyme disease, in blood or cerebrospinal fluid. A positive result typically leads to a confirmatory Western blot test as part of the two-tier testing approach recommended by the CDC.

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).

If you see 86618 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 86618 often also see these adjacent codes on the same bill.

Related BillBusted guides

Plain-English reads if you see 86618 on a bill.

86618 FAQ

Plain-English answers.

What does 86618 usually cost?

$15–$35 Medicare allowed (CMS CLFS); $25–$100 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 86618?

Billing 86618 (Lyme immunoassay/ELISA) and 86617 (Lyme antibody confirmation) together without documentation that both tiers were ordered — two-tier testing is appropriate, but both must be documented

What should I do if I see 86618 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 86618 before paying.

Don't pay 86618 blindly.

The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.