CPT code 86695 – Herpes simplex type 1 antibody test

Key takeaways

CPT code 86695 covers HSV type 1 antibody serology only. Type 2 serology is billed with the companion code 86696.

B00.9, Z11.59 and Z20.828 are the most common ICD-10-CM pairings, but Z11.59 on an asymptomatic Medicare patient carries a high denial risk.

Medicare pays 86695 under the Clinical Laboratory Fee Schedule, and coverage rules come from your MAC’s local coverage determination.

Modifier -91 covers clinically indicated repeat testing on the same date of service, and modifier -59 separates 86695 from bundled codes.

CPT code 86695: Definition and clinical scope

CPT code 86695 is an immunology serology code in the 86000-86849 range. It is published by the American Medical Association (AMA) as part of the annual CPT code set.

The official descriptor reads: Antibody; herpes simplex, type 1. The test measures HSV-1-specific antibodies, typically IgG, IgM, or both. Labs run it by ELISA, chemiluminescent microparticle immunoassay (CMIA), or indirect fluorescent antibody (IFA) methods.

The code covers antibody testing on serum, or less often on cerebrospinal fluid. It does not cover direct viral detection methods such as PCR or culture, which use separate codes. A CLIA-certified laboratory must perform and report the test, and the requisition must carry the ordering physician’s name and NPI.

CPT 86695 vs CPT 86696: Choosing the right code

86695 covers HSV type 1 antibody testing, and 86696 covers HSV type 2. The two codes are not interchangeable. Billing 86695 for a type-2-specific order is a coding error, and it draws a CO-4 denial however well the test is justified.

Both codes may be reported on the same date of service when the physician explicitly orders type-specific testing for both HSV-1 and HSV-2. That happens most often in STI baseline panels, TORCH workups, and immunocompromised patient evaluations. Document the clinical indication for each type separately in the requisition.

Clinical indications and when to order HSV-1 antibody testing

Accepted clinical indications drive medical necessity and determine which ICD-10-CM code supports the claim. The most commonly covered situations in sexual health and general practice include:

• Suspected primary HSV-1 infection: oral or perioral vesicles, gingivostomatitis, or pharyngitis in a patient without prior serology
• STI screening panels: when ordered as part of a comprehensive baseline workup alongside other STI testing
• TORCH workup in pregnancy: toxoplasmosis, rubella, cytomegalovirus, and herpes panel for neonatal risk assessment
• Immunocompromised patient evaluation: HIV-positive patients, transplant recipients, or patients on immunosuppressive therapy
• Viral encephalitis workup: HSV-1 is the most common cause of sporadic viral encephalitis; serology may support CSF findings
• Exposure or contact tracing: documented contact with a known HSV-1-positive individual

Asymptomatic general screening, without any of the indicators above, is typically not a covered Medicare indication. The Centers for Disease Control and Prevention (CDC) does not recommend routine HSV serology for the general population.

Most Medicare Administrative Contractor (MAC) local coverage determinations (LCDs) follow the same line. Claims paired with Z11.59 alone on an asymptomatic patient carry high denial risk.

ICD-10-CM codes to pair with CPT 86695

In medical billing, the diagnosis code is what proves a lab test was necessary. Each code paired with CPT 86695 must reflect the documented clinical indication, not a default placeholder.

Verify accepted diagnosis codes against the applicable MAC Local Coverage Determination before billing. LCD coverage lists change annually, and a code accepted under one MAC’s policy may not be accepted under another’s.

Medicare and Medicaid coverage for CPT code 86695

CPT code 86695 is reportable under Medicare’s Clinical Laboratory Fee Schedule (CLFS). Coverage is governed by the LCD of the MAC that serves the laboratory, not the one where the patient receives care.

Meeting medical billing compliance requirements for this code means checking that the ordering indication falls within that active LCD before the claim goes out.

• ABN requirement: testing may be ordered for an indication the applicable LCD does not list. In that case, the laboratory must obtain a signed Advance Beneficiary Notice of Noncoverage (ABN, form CMS-R-131) before collecting the specimen. Without a signed ABN, the lab cannot bill the patient if Medicare denies the claim.
• Frequency limitations: most MAC LCDs set no strict frequency limit for HSV-1 serology. Repeat testing within 90 days on the same indication will still prompt a medical necessity review. Serial monitoring during active infection or immunosuppressive therapy is the usual documented justification.
• Medicaid: coverage varies by state. Most state Medicaid programs follow Medicare LCD logic for HSV serology. Some require prior authorization for certain indications. Check the state’s fee schedule and PA requirements separately.
• CLIA certification: the performing laboratory must hold a CLIA certificate at or above the complexity level of the assay. Sending claims from an uncertified lab results in a CO-B7 or similar denial.

Reimbursement rates and fee schedules for CPT 86695

The Medicare Clinical Laboratory Fee Schedule (CLFS) sets one national payment rate for CPT code 86695. Unlike the physician fee schedule, the CLFS has no locality adjustment.

Download the current rate from the CMS clinical laboratory fee schedule files. Avoid hardcoding it in your billing system, because CMS republishes the CLFS file every quarter.

Commercial payers typically price HSV-1 serology at or near the Medicare CLFS rate as a benchmark. Some managed care contracts pay a percentage of Medicare, such as 110% of the CLFS rate. Place of service also affects reimbursement.

How to document and bill CPT 86695

Documentation must support both the test order and the diagnosis code on the claim. A clean claim submission for 86695 requires each of these elements to be present before the claim leaves the practice or lab.

1. Signed test requisition: ordering physician’s name, NPI, and signature, with the clinical indication written in plain language (not just the ICD-10 code number)
2. Specimen documentation: collection date, specimen type (serum), and collection site; date of service on the claim must match the collection date
3. Method on the lab report: the assay method (ELISA, CMIA, IFA) must appear on the final report to confirm the service matches the billed code
4. CLIA certificate number: include the performing laboratory’s CLIA number in Box 23 of the CMS-1500, or its electronic equivalent (837P loop 2300, REF segment)
5. Result and interpretation: the lab report must include numeric or qualitative results and a reference range. An incomplete report is an audit risk even if the claim pays

For send-out tests, Medicare generally requires the performing laboratory to bill the test itself. If a commercial payer lets the ordering practice bill, the claim must carry the performing lab’s CLIA number. It must also identify that lab, not the ordering office.

Modifiers for CPT 86695

Modifier selection for 86695 depends on the clinical scenario. Using the wrong modifier, or omitting one that the payer requires, is a common denial trigger for laboratory claims.

Verify NCCI edit pairs for 86695 quarterly using the current CMS NCCI table. Edit pairs change, and an edit that did not exist last quarter may bundle 86695 with a panel code this quarter. See the AAPC Codify CPT lookup for modifier compatibility references.

Common claim denial reasons and how to avoid them

The typical 86695 denial starts with an “HSV panel” order. A coder assigns 86695 without checking which type the physician meant, then pairs it with Z11.59 on an asymptomatic Medicare patient.

The result is a CO-4 (incorrect code) or CO-11 (diagnosis inconsistent with procedure) denial, sometimes both on one claim. Structured denial management workflows stop both with the two checks below.

• Wrong code selected (CO-4): 86695 used when the order specified type 2 or non-type-specific HSV. Resolution: query the ordering provider before billing; do not default to 86695 for any HSV antibody order.
• ICD-10 mismatch (CO-11): diagnosis code does not support the procedure. Resolution: confirm the clinical indication is documented in the chart note and matches the ICD-10 code on the claim.
• Asymptomatic screening denial: Z11.59 or Z00.00 on a Medicare patient with no documented exposure or symptoms. Resolution: obtain a signed ABN before specimen collection; consider whether the order has a covered indication at all.
• Missing CLIA number: CO-B7 denial when CLIA certificate data is absent from the claim. Resolution: include the performing lab’s CLIA number in Box 23 on every lab claim.
• Ordering physician NPI missing: payer rejects the claim as incomplete. Resolution: include the ordering physician’s NPI in the appropriate claim field, separate from the billing provider NPI.
• Bundling with panel codes: payer applies NCCI edits and bundles 86695 into a broader panel code. Resolution: append modifier -59 with documentation that the type-specific HSV-1 test was separately indicated; check current NCCI edit tables quarterly.

Our guide to medical billing denial codes maps each CO code to its root cause and resolution path. On 86695, CO-4 and CO-11 are the two to watch.

Prior authorization requirements

Medicare does not require prior authorization for CPT code 86695 as a matter of national policy. Commercial payers vary significantly. Prior authorization is most likely when HSV-1 serology is ordered as a standalone test outside a recognized panel. It is also common when the patient’s plan routes lab benefits through a carve-out laboratory benefit manager.

• When PA is commonly required: standalone HSV-1 serology without an STI panel, repeat testing within 90 days, and Medicaid managed care plans with lab carve-outs
• What to submit with the PA request: the clinical note documenting the indication, the relevant ICD-10-CM code, and the requisition naming the specific assay
• When authorization is denied: appeal with the clinical criteria supporting the indication, such as CDC STI screening guidelines or obstetric TORCH guidance. Attach the treating physician’s attestation

PA requirements change annually with plan year updates. Verify requirements directly with the patient’s payer before ordering, not after the specimen is collected.

Billing CPT 86695 alongside related codes

Co-billing scenarios for 86695 require attention to NCCI edits, which the Centers for Medicare and Medicaid Services (CMS) updates quarterly. Check the current NCCI table against any codes billed on the same date of service.

• 86695 + 86696 (same date): reportable when both type-1 and type-2 antibody testing are explicitly ordered. Append modifier -59 to 86696 if the payer bundles. Document the separate clinical rationale for each test.
• 86695 within a TORCH panel: TORCH panels have their own CPT codes. Billing 86695 separately alongside a TORCH panel code may trigger a NCCI edit. Confirm whether the HSV-1 component is included in the panel code before reporting both.
• 86695 + other immunology codes: when multiple immunology serology codes are ordered on the same day, NCCI edit pairs may apply. Check CrossCoder for current procedure-to-procedure edits before submission.

Submitting through a medical claims clearinghouse adds a scrubbing step that flags NCCI edit conflicts before claims leave the practice. That cuts co-billing denials at the source rather than at appeal.

How claims management software prevents 86695 denials

Without a check before submission, an 86695 coding error usually surfaces when the remittance comes back with CO-4 or CO-11. By then the specimen has shipped, and the fix means a provider query plus a resubmission.

Pabau, the practice management platform we build, moves that check to the front. Its claims management software connects to Claim.MD, our integrated US clearinghouse, for 837P submission, real-time eligibility checks and ERA posting.

Claims are scrubbed before they reach the payer. A mismatch between code, diagnosis and place of service gets flagged while it is still cheap to fix. Your team spends less time reworking lab claims and gets paid faster on the ones that were right first time.

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Pabau connects with Claim.MD for electronic lab claim submission, real-time eligibility checks and ERA posting. Your team spends less time on rework and more time on patient care.

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Conclusion

Treat every HSV antibody order as unbillable until the requisition names a type and the chart supports the diagnosis. That single habit protects 86695 claims from both of the denials that hit this code hardest.

The trade-off is a slower handoff on vague requisitions, since someone has to query the ordering provider. That delay costs far less than an appeal, and it teaches providers to write type-specific orders from the start.

Book a demo to see how Pabau catches code and diagnosis mismatches on lab claims before they reach the payer.

Continue your research

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