TL;DR: The Centers for Medicare & Medicaid Services retired NCD 160.22, its National Coverage Determination governing ambulatory EEG monitoring, effective January 1, 2023 — and a March 7, 2026 policy update to NCD 215 formally documents that retirement. If your billing team is still treating this NCD as active guidance, you're working off a dead policy.
CMS's NCD 215 (policy key 215-v3) covers ambulatory, or 24-hour, electroencephalographic (EEG) monitoring — the cassette-based recording of brain wave patterns across a patient's routine daily activities and sleep. The March 7, 2026 modification codifies the retirement status of NCD 160.22 and signals that local contractor discretion now governs Medicare coverage for this service. No specific CPT or HCPCS codes are listed in the policy document.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Centers for Medicare & Medicaid Services (CMS) |
| Policy | Ambulatory EEG Monitoring — RETIRED |
| Policy Code | NCD 215 (policy key 215-v3) |
| Change Type | Modified |
| Effective Date | 2026-03-07 |
| Impact Level | Medium |
| Specialties Affected | Neurology, clinical neurophysiology, hospital outpatient departments, independent diagnostic testing facilities (IDTFs) |
| Key Action | Stop relying on NCD 160.22 for coverage determinations; audit open claims and verify LCD guidance with your local MAC before March 7, 2026 |
CMS Ambulatory EEG Monitoring Coverage Criteria and Medical Necessity Requirements 2026
NCD 160.22 is retired, full stop, as of January 1, 2023. The March 7, 2026 update to NCD 215 is CMS making that retirement official in the current policy record — it's a documentation update, not a new clinical change. But if your team missed the 2023 retirement, this is the moment to correct course.
When a national coverage determination is retired, Medicare coverage for that service doesn't automatically disappear. It shifts. Your local Medicare Administrative Contractor (MAC) steps in with a Local Coverage Determination (LCD) or, absent an LCD, applies general medical necessity standards under the Social Security Act. That means your billing guidelines, prior authorization requirements, and reimbursement expectations now depend entirely on which MAC processes your claims.
This matters because MAC coverage policies for ambulatory EEG aren't uniform. If you bill in a jurisdiction covered by Noridian, Novitas, or CGS, for example, those contractors may have their own LCDs with different coverage criteria, medical necessity documentation requirements, and applicable codes. Check your MAC's website now — don't assume a retired NCD means open-season billing.
CMS Ambulatory EEG Monitoring Exclusions and Non-Covered Indications
The retired NCD 160.22 itself doesn't enumerate specific exclusions in the current policy document. With the NCD gone, coverage exclusions are now defined at the local level.
Your MAC may treat certain ambulatory EEG indications as not medically necessary, experimental, or outside coverage without an LCD specifically supporting them. If you're billing for extended ambulatory EEG monitoring outside the classic 24-hour cassette-recorder context — including newer long-term video-EEG or wireless ambulatory monitoring — expect local contractors to scrutinize medical necessity documentation closely. The absence of a national standard cuts both ways: it removes a coverage floor and removes a coverage ceiling.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Ambulatory (24-hour) EEG monitoring via cassette recorder | Governed by local MAC policy post-NCD retirement | None listed in NCD 215 | NCD 160.22 retired 01-01-2023; check your MAC's LCD |
| All other ambulatory EEG indications | Governed by local MAC policy | None listed in NCD 215 | No national standard; medical necessity determined locally |
No codes are listed in the NCD 215 policy document. Derive applicable CPT codes from your MAC's current LCD or coverage article.
CMS Ambulatory EEG Monitoring Billing Guidelines and Action Items 2026
| # | Action Item |
|---|---|
| 1 | Pull your MAC's current LCD on ambulatory EEG before March 7, 2026. Go to the CMS LCD database at cms.gov or your MAC's portal directly. If an LCD exists, it's your new coverage bible — read the medical necessity criteria line by line. |
| 2 | Audit any claims billed under NCD 160.22 criteria after January 1, 2023. The NCD was retired effective that date. Claims submitted with documentation or coverage justification tied to the retired NCD could face denial or recoupment if audited. Identify any exposure in your accounts receivable now. |
| 3 | Update your internal billing guidelines to remove all references to NCD 160.22. It's retired. Any charge capture workflows, payer policy reference sheets, or coder training materials that cite that NCD need revision today — not after March 7, 2026. |
| 4 | Confirm which CPT codes your MAC recognizes for ambulatory EEG. NCD 215 lists no codes. Your MAC's LCD or coverage article will specify the applicable codes. Don't bill codes you've historically used without verifying they're still supported under local policy. |
| 5 | Document medical necessity at the encounter level, every time. With no national standard to anchor coverage, your clinical documentation carries more weight than it did under a standing NCD. The physician's rationale for ordering ambulatory EEG monitoring needs to map explicitly to your MAC's medical necessity criteria in the chart note. |
| 6 | If your claim denial rate on ambulatory EEG climbs after March 7, 2026, it's a documentation or code-mapping issue — not a payer error. The most common post-NCD-retirement billing failure is continuing to bill as if a national standard still exists. If your MAC denies a claim, read the remittance code carefully and cross-reference the LCD. |
| 7 | Loop in your compliance officer if you have significant ambulatory EEG billing volume. The shift from national to local coverage determination creates audit risk, particularly for high-volume neurology practices and IDTFs. A compliance review of your current workflows is worth the time. |
| 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 Ambulatory EEG Monitoring Under NCD 215
The NCD 215 policy document does not list specific CPT, HCPCS Level II, or ICD-10-CM codes. This is consistent with the retirement of NCD 160.22 — CMS is no longer maintaining a national code-level framework for this service.
How to Find Applicable Codes
To identify the correct CPT codes for ambulatory EEG monitoring billing under Medicare, go directly to your MAC's LCD or associated billing and coding article. These documents typically enumerate covered CPT codes, non-covered codes, and required ICD-10-CM diagnosis codes for medical necessity substantiation.
Common MACs to check based on your jurisdiction include Noridian, Novitas Solutions, CGS Administrators, First Coast Service Options, and WPS Government Health Administrators. Each maintains a searchable LCD database on their portal.
No Codes Listed in Policy
| Code Type | Status |
|---|---|
| CPT | No codes listed in NCD 215 |
| HCPCS Level II | No codes listed in NCD 215 |
| ICD-10-CM | No codes listed in NCD 215 |
Do not infer code coverage from this policy document. Verify with your MAC before billing.
The Real Issue With This Change
A retired NCD is a coverage vacuum, and vacuums get filled inconsistently. Some MACs have detailed LCDs for ambulatory EEG with clear indications and code-level guidance. Others don't. If your MAC lacks an LCD and you're relying on general medical necessity principles, your claim denial risk is higher and your documentation burden is heavier.
This isn't a crisis — ambulatory EEG monitoring is an established diagnostic tool and MACs generally recognize legitimate clinical use. But the billing environment for this service is materially less predictable than it was under a standing NCD. That's the tradeoff CMS made when it retired 160.22, and it's the reality your billing team needs to operate in.
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