TL;DR: The Centers for Medicare & Medicaid Services modified NCD 265 governing Medicare serologic testing for HIV/AIDS, with an effective date of 2026-01-09. Here's what billing teams need to know before submitting claims.
CMS HIV/AIDS serologic testing coverage policy under NCD 265 Medicare draws a hard line: diagnostic testing for symptomatic patients is covered, and screening for asymptomatic patients is not. This NCD 265 Medicare policy also enforces a specific sequencing rule for Western blot testing that will get your claim denied if you miss it. This policy does not list specific CPT or HCPCS codes — which creates its own documentation burden.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Serologic Testing for Acquired Immunodeficiency Syndrome (AIDS) |
| Policy Code | NCD 265 |
| Change Type | Modified |
| Effective Date | 2026-01-09 |
| Impact Level | Medium |
| Specialties Affected | Infectious Disease, Internal Medicine, Primary Care, Clinical Laboratory |
| Key Action | Confirm symptomatic diagnosis documentation and dual-ELISA sequencing before billing Western blot testing |
CMS HIV/AIDS Serologic Testing Coverage Criteria and Medical Necessity Requirements 2026
The core coverage rule here is straightforward — but billing teams get it wrong often enough that it's worth stating plainly. Medicare covers HIV/AIDS serologic testing when a provider performs it to establish a diagnosis in a symptomatic patient. That means documented signs or symptoms that clinically justify the test order.
Medical necessity is the gating issue. If a patient has no symptoms, Medicare does not cover the test. This is a categorical exclusion, not a gray area. There's no documentation workaround that converts a screening test on an asymptomatic patient into a covered diagnostic test.
The Centers for Medicare & Medicaid Services also enforces a specific testing sequence for Western blot reimbursement. The coverage policy requires two enzyme-linked immunosorbent assay (ELISA) tests — both run on the same specimen — to return positive results before Medicare will pay for a Western blot or immunofluorescent assay (IFA). Submit a Western blot without that dual-ELISA foundation and you're looking at a claim denial.
Prior authorization is not explicitly required by NCD 265. That said, your Medicare Administrative Contractor may have local coverage determination rules that layer additional requirements on top of this NCD. Check with your MAC before assuming this NCD is the whole story.
The real exposure here is on the diagnostic vs. screening distinction. Physicians sometimes order HIV testing as part of a broader workup for symptomatic patients but document the encounter in a way that reads more like a wellness visit. That documentation pattern triggers medical necessity scrutiny. Your billing team and your compliance officer need to be aligned on what the medical record is actually showing before the claim goes out.
CMS HIV/AIDS Serologic Testing Exclusions and Non-Covered Indications
This is where the claims pile up. The exclusion is blunt: serologic testing furnished as part of a screening program for asymptomatic persons is not covered under NCD 265.
This matters in practice because HIV screening is now a USPSTF Grade A recommendation for adults aged 15–65. Many providers have integrated HIV screening into routine preventive care. Medicare covers that screening under a separate preventive services benefit — not under NCD 265 diagnostic billing guidelines. Billing a diagnostic code to justify what is functionally a screening test is a documentation compliance problem, not just a claim issue.
If your practice or laboratory is seeing orders for HIV testing tied to annual wellness visits or preventive encounters, those tests should not route through NCD 265 coverage policy. Mixing these billing pathways is how you generate overpayment exposure.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| HIV/AIDS serologic testing for symptomatic patients (diagnostic) | Covered | Policy does not list specific codes | Medical necessity documentation required; symptomatic diagnosis must be supported in the record |
| ELISA (initial test on specimen) | Covered (as part of diagnostic workup) | Policy does not list specific codes | Must be performed for symptomatic patient |
| Repeat ELISA on same specimen (reactive initial result) | Covered (as part of diagnostic workup) | Policy does not list specific codes | Second ELISA must be on same specimen |
| Western blot or immunofluorescent assay (IFA) | Covered (conditional) | Policy does not list specific codes | Both ELISA tests on same specimen must be positive before Western blot is covered |
| HIV/AIDS serologic testing for asymptomatic persons (screening) | Not Covered under NCD 265 | N/A | Screening programs for asymptomatic patients are categorically excluded; bill under appropriate preventive benefit if applicable |
CMS HIV/AIDS Serologic Testing Billing Guidelines and Action Items 2026
This policy puts the documentation burden squarely on your side of the claim. Here's what to do before 2026-01-09 and on every HIV serologic testing claim going forward.
| # | Action Item |
|---|---|
| 1 | Audit your current HIV testing orders for symptomatic documentation. Pull claims from the past 90 days. For every HIV serologic test billed under a diagnostic code, confirm the medical record shows documented symptoms that justify the test. If the record looks like a routine screen, flag it for your compliance officer before the claim goes out or gets audited. |
| 2 | Build a sequencing check into your lab billing workflow. Before billing a Western blot or IFA, verify that two ELISA tests — both run on the same specimen — returned positive results. This is a hard coverage rule. There is no medical necessity exception. If your lab or billing system doesn't track specimen-level sequencing, create a manual checkpoint now. |
| 3 | Separate your HIV screening and HIV diagnostic billing tracks. Asymptomatic patients getting HIV screening as part of preventive care should never route through NCD 265. Map those encounters to the appropriate Medicare preventive benefit. Talk to your compliance officer if you're unsure how your current workflow handles this split. |
| 4 | Check with your MAC for local coverage determination requirements. NCD 265 is the national baseline. Your Medicare Administrative Contractor may have an LCD that adds documentation requirements, code-specific billing guidelines, or frequency limitations. Contact your MAC directly or review their LCD database before the effective date of January 9, 2026. |
| 5 | Flag the absence of specific codes in this policy. NCD 265 does not list specific CPT or HCPCS codes. That means your billing team needs to apply clinical judgment — and solid documentation — to determine which codes map to these services. If you're not certain which laboratory codes apply to ELISA, Western blot, or IFA testing in your charge capture system, pull in a billing consultant before submitting claims under this updated policy. Code mismatches without a strong documentation record are a fast path to a claim denial. |
| 6 | Train your front-end team on the diagnostic vs. screening distinction. The people capturing encounter data and coding diagnoses need to understand that "HIV test" is not a single billing category under Medicare. The clinical context — symptomatic vs. asymptomatic — determines whether NCD 265 applies at all. This is a training gap at many practices, especially those that also see commercial patients where this distinction doesn't matter as much. |
| 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 HIV/AIDS Serologic Testing Under NCD 265
Covered Codes (When Medical Necessity Criteria Are Met)
NCD 265 does not specify CPT or HCPCS codes. The policy describes the covered services — ELISA testing, repeat ELISA on the same specimen, and Western blot or immunofluorescent assay following two positive ELISAs — but does not list the billing codes that correspond to those services.
This is a real operational gap. Your billing team needs to confirm the correct laboratory CPT codes for ELISA, Western blot, and IFA testing through your charge description master and verify alignment with your MAC's billing guidelines.
| Code | Type | Description |
|---|---|---|
| Not specified in NCD 265 | — | Policy covers ELISA, repeat ELISA, Western blot, and IFA testing for symptomatic HIV/AIDS diagnosis — codes not enumerated |
Not Covered Under NCD 265
| Service | Reason |
|---|---|
| HIV serologic testing for asymptomatic persons | Categorically excluded; not covered as a screening program under NCD 265 |
| Western blot before two positive ELISAs on same specimen | Coverage condition not met; claim will deny |
Key ICD-10-CM Diagnosis Codes
NCD 265 does not list specific ICD-10-CM codes. Medical necessity documentation should reflect the symptomatic presentation that clinically justifies diagnostic HIV testing. Work with your clinical and coding teams to ensure the diagnosis codes on the claim support a diagnostic — not preventive — encounter.
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