TL;DR: The Centers for Medicare & Medicaid Services modified NCD 216 governing stereotaxic depth electrode implantation, effective March 7, 2026. Here's what billing teams need to know about this coverage policy and how to handle claims correctly.
CMS stereotaxic depth electrode implantation coverage policy under NCD 216 in the CMS Medicare system has been updated as a modification. The policy covers the implantation of thin wire electrodes into the brain of focal epilepsy patients for EEG monitoring prior to surgical treatment. No specific CPT or HCPCS codes are listed in the current policy document — that's a billing issue your team needs to address now, before claims go out the door.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Stereotaxic Depth Electrode Implantation |
| Policy Code | NCD 216 |
| Change Type | Modified |
| Effective Date | 2026-03-07 |
| Impact Level | Medium |
| Specialties Affected | Neurology, Neurosurgery, Epilepsy Centers, Hospital Outpatient |
| Key Action | Audit your charge capture for depth electrode implantation claims and confirm your MAC's billing guidelines before filing after March 7, 2026 |
CMS Stereotaxic Depth Electrode Implantation Coverage Criteria and Medical Necessity Requirements 2026
CMS covers stereotaxic depth electrode implantation when it is performed prior to surgical treatment of focal epilepsy. The patient must be unresponsive to anticonvulsant medications. That's the core medical necessity gate — and it's non-negotiable.
The procedure works by implanting thin wire electrodes into the brain of a focal epileptic patient. The electrodes monitor EEG activity during seizure events. The goal is to localize the epileptic focus so that surgical treatment decisions are better informed.
CMS found this procedure both safe and effective for a specific purpose: diagnosing resectable seizure foci that conventional scalp EEGs miss. That language matters for your medical necessity documentation. If the clinical record doesn't show a failed scalp EEG workup, your claim is vulnerable.
The coverage policy is clear that this is a diagnostic procedure within the surgical treatment pathway. It is not covered as a standalone monitoring tool outside of the pre-surgical context. Medical necessity documentation must show the patient is a surgical candidate with intractable seizures that have not responded to medications.
Depth electrode implantation billing sits at the intersection of neurology and neurosurgery, which means your documentation chain often spans two departments. Make sure both are aligned on what CMS requires before the claim drops.
No prior authorization requirement is explicitly stated in NCD 216. However, your Medicare Administrative Contractor may impose additional local coverage determination requirements on top of this national policy. Check with your MAC before assuming the NCD is the only hurdle.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Stereotaxic depth electrode implantation prior to surgical treatment of focal epilepsy, in patients unresponsive to anticonvulsant medications | Covered | No codes listed in NCD 216 — confirm with MAC | Scalp EEG must have been insufficient to identify seizure focus; patient must be a surgical candidate |
| Depth electrode implantation outside pre-surgical context (e.g., general monitoring only) | Not Covered | N/A | Coverage policy applies only to the diagnostic pre-surgical use case |
| Patients responsive to anticonvulsant medications | Not Covered | N/A | Medical necessity requires documented failure of anticonvulsant therapy |
CMS Stereotaxic Depth Electrode Implantation Billing Guidelines and Action Items 2026
NCD 216 in the Medicare system does not list specific CPT or HCPCS codes. That's the first problem your billing team needs to solve. Here's how to handle it.
| # | Action Item |
|---|---|
| 1 | Contact your MAC immediately. Your Medicare Administrative Contractor is the right source for billing codes and local coverage determination guidance tied to this procedure. Don't wait until after March 7, 2026, to make that call. MACs sometimes publish billing instructions that supplement NCDs without those instructions appearing in the NCD itself. |
| 2 | Pull your remittance history for depth electrode claims. Look at how your team has been coding this procedure over the last 12 months. If the modification changed any coverage criteria or documentation expectations, you need to know which claims may have been filed under different assumptions. |
| 3 | Audit your medical necessity documentation template. Every depth electrode implantation claim needs to show three things: focal epilepsy diagnosis, documented failure of anticonvulsant medications, and a prior inadequate scalp EEG. If your intake or pre-op checklist doesn't capture all three, fix it before the effective date of March 7, 2026. |
| 4 | Confirm the pre-surgical context in the operative and clinical notes. CMS coverage requires that this procedure precedes surgical treatment. The clinical documentation must make that treatment plan explicit. A claim that reads as a standalone monitoring procedure is a claim denial waiting to happen. |
| 5 | Coordinate between neurology and neurosurgery documentation. These claims often straddle two service lines. The neurologist's EEG interpretation and the neurosurgeon's surgical plan both need to appear in the record. A gap between those two documents is a medical necessity audit risk. |
| 6 | Review reimbursement rates with your finance team. Because NCD 216 does not list codes, your current reimbursement benchmarks may be tied to MAC-specific fee schedule allowances. Confirm those rates are still accurate under the modified policy. If your MAC issues updated billing instructions after March 7, 2026, your reimbursement expectations may shift. |
| 7 | Loop in your compliance officer if you're unsure how this applies to your patient population. This NCD applies broadly, but the surgical candidacy requirement creates real gray area for patients in active medication trials. If your epilepsy center treats patients at various stages of the medication-to-surgery continuum, your compliance officer should weigh in on where the coverage line sits for your specific case mix. |
| 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 Stereotaxic Depth Electrode Implantation Under NCD 216
NCD 216 does not list specific CPT, HCPCS, or ICD-10 codes. This is not unusual for older NCDs, but it creates a real billing gap.
Your MAC is the authoritative source for the correct procedure codes to use when billing stereotaxic depth electrode implantation under Medicare. Some MACs publish companion billing articles alongside NCDs that specify the applicable codes. Search your MAC's website for billing articles associated with NCD 216 or contact your MAC's provider outreach line directly.
For ICD-10-CM diagnosis coding, your clinical documentation should support a focal epilepsy diagnosis with intractability. The specific code your coder selects needs to match the clinical record precisely. An epilepsy code that doesn't specify intractability — when the record clearly shows failed anticonvulsant therapy — is a soft target in an audit.
Do not guess at codes for this procedure. The combination of a high-acuity surgical procedure, a neurology-neurosurgery handoff, and a CMS policy that doesn't list codes is exactly the scenario where a coding assumption turns into a claim denial or a post-payment audit finding.
CMS NCD 216 in Context: What the Modification Means for Your Program
The real issue here is that NCD 216 has been around long enough that some billing teams treat it as settled. A modification notice is a signal to re-examine your assumptions.
The core coverage policy hasn't changed dramatically — focal epilepsy, failed medications, pre-surgical context. But modifications to NCDs often reflect updated CMS thinking on documentation requirements, coverage scope, or claim submission expectations. The fact that no codes are listed in the published policy means your MAC's local guidance is doing a lot of heavy lifting here.
This is also a good moment to think about how your program documents the "failed anticonvulsant" requirement. CMS doesn't define a specific number of medications or duration of treatment. That ambiguity creates exposure. Your medical director and compliance officer should agree on what "unresponsive to anticonvulsant medications" means in your documentation standards — and that standard should be written down, not just understood.
Epilepsy programs at academic medical centers and large hospital systems tend to have well-developed workflows for this. Smaller neurology practices and community hospitals doing lower volumes of these procedures are more likely to have inconsistent documentation. If you're in the latter group, this modification is a prompt to tighten things up.
Get the Full Picture
Track this policy across versions, search 1,500+ policies by CPT code, and get real-time alerts when any payer changes coverage.