TL;DR: Aetna, a CVS Health company, modified CPB 0289 covering grid monitoring and intraoperative electroencephalography, effective September 26, 2025. If your team bills CPT 95829, 95940, 95941, or 95955, review your selection criteria documentation now.
This update to CPB 0289 in the Aetna system affects coverage for electrocorticography, continuous intraoperative neurophysiology monitoring (IONM), and EEG during non-intracranial surgery. Seven CPT codes sit in the "covered if selection criteria are met" bucket — and that conditional language is where claims get denied. The effective date is September 26, 2025, so your billing team has no runway to wait on this.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Aetna, a CVS Health company |
| Policy | Grid Monitoring and Intraoperative Electroencephalography |
| Policy Code | CPB 0289 |
| Change Type | Modified |
| Effective Date | September 26, 2025 |
| Impact Level | High |
| Specialties Affected | Neurology, Neurosurgery, Neurophysiology, Anesthesiology, Vascular Surgery |
| Key Action | Audit selection criteria documentation for CPT 95829, 95940, 95941, and 95955 before billing on or after September 26, 2025 |
Aetna Grid Monitoring and Intraoperative EEG Coverage Criteria and Medical Necessity Requirements 2025
The Aetna grid monitoring and intraoperative electroencephalography coverage policy under CPB 0289 covers seven CPT codes — but only when selection criteria are met. That phrase does a lot of work. It means your documentation has to prove medical necessity before Aetna will pay.
The covered codes fall into two clinical categories. The first is intraoperative monitoring: CPT 95829 for electrocorticogram at surgery, CPT 95940 for continuous IONM with one-on-one monitoring in the operating room, CPT 95941 for remote or nearby continuous IONM from outside the OR, and CPT 95955 for EEG during non-intracranial surgery such as carotid procedures. The second category covers extended EEG monitoring: CPT 95812 for 41–60 minutes, CPT 95813 for more than one hour, and CPT 95822 for recording in coma or sleep only.
Medical necessity documentation needs to match the clinical scenario precisely. For IONM codes like 95940 and 95941, that means documenting the specific neurological structures at risk during the procedure. For EEG codes 95812 and 95813, documentation must justify the extended monitoring duration — not just order it.
Prior authorization requirements for these services vary by plan. Don't assume your prior auth process from six months ago still applies. Check the current requirements under the updated CPB 0289 Aetna system before scheduling cases on or after September 26, 2025.
The real exposure here is on the IONM side. CPT 95940 and 95941 carry significant reimbursement value. If your documentation doesn't clearly satisfy Aetna's selection criteria, you're looking at a claim denial with a rocky appeals path — especially since Aetna will cite the "criteria not met" language directly.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Electrocorticogram at surgery | Covered — criteria must be met | CPT 95829 | Selection criteria required; document neurological risk |
| Continuous IONM — in-room, one-on-one | Covered — criteria must be met | CPT 95940 | Selection criteria required; specify structures monitored |
| Continuous IONM — remote or nearby | Covered — criteria must be met | CPT 95941 | Selection criteria required; remote monitoring documentation required |
| EEG during non-intracranial surgery (e.g., carotid) | Covered — criteria must be met | CPT 95955 | Selection criteria required; document surgical indication |
| Extended EEG monitoring, 41–60 minutes | Covered — criteria must be met | CPT 95812 | Selection criteria required; justify duration in documentation |
| Extended EEG monitoring, greater than 1 hour | Covered — criteria must be met | CPT 95813 | Selection criteria required; justify duration in documentation |
| EEG in coma or sleep only | Covered — criteria must be met | CPT 95822 | Selection criteria required; document clinical indication |
| Intracranial and related surgical procedures | Related procedures | CPT 31200–31230, 61000–61041 and additional codes | Contextual/associated procedures; coverage governed by respective policies |
Aetna Intraoperative EEG Billing Guidelines and Action Items 2025
The coverage policy is conditional throughout. Every action item below flows from that fact.
| # | Action Item |
|---|---|
| 1 | Audit your selection criteria documentation before September 26, 2025. Pull a sample of recent claims for CPT 95829, 95940, 95941, and 95955. Check whether your operative notes and physician orders explicitly address the criteria Aetna requires. If they don't, work with your clinical documentation improvement team now. |
| 2 | Verify prior authorization requirements under the updated policy. Call Aetna or check the provider portal for your specific plan types. Prior auth requirements for intraoperative neurophysiology monitoring billing can shift when a policy is modified. Assume nothing carried over unchanged. |
| 3 | Separate 95940 and 95941 billing correctly. These two codes are not interchangeable. CPT 95940 requires the monitoring professional to be physically present in the operating room. CPT 95941 covers remote or nearby monitoring from outside the OR. Billing the wrong code is a claim denial waiting to happen. |
| 4 | Confirm ICD-10 linkage for every IONM claim. The diagnosis codes attached to your 95940 and 95941 claims must reflect why monitoring was medically necessary. A generic neurological diagnosis won't hold up if Aetna's selection criteria require specificity about the structures at risk. |
| 5 | Flag the intracranial surgical procedure codes as contextual. CPT codes in the 31200–31230 and 61000-series ranges appear in CPB 0289 as related procedures, not independently covered services under this bulletin. Don't bill them under CPB 0289 criteria — their coverage is governed by separate policies. |
| 6 | Update your charge capture templates. Make sure the seven covered CPT codes — 95812, 95813, 95822, 95829, 95940, 95941, and 95955 — have documentation prompts tied to Aetna's selection criteria. A charge capture workflow that doesn't force documentation review is a revenue leak. |
| 7 | If your practice bills high volumes of 95941 for remote IONM, talk to your compliance officer. Remote monitoring has drawn scrutiny across multiple payers. The modification to CPB 0289 may signal tightening criteria. Review the full updated bulletin and have your compliance officer assess exposure before the effective date. |
| 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 Grid Monitoring and Intraoperative EEG Under CPB 0289
Covered CPT Codes (When Selection Criteria Are Met)
| Code | Type | Description |
|---|---|---|
| 95812 | CPT | Electroencephalogram (EEG) extended monitoring; 41–60 minutes |
| 95813 | CPT | Electroencephalogram (EEG) extended monitoring; greater than 1 hour |
| 95822 | CPT | Electroencephalogram (EEG); recording in coma or sleep only |
| 95829 | CPT | Electrocorticogram at surgery (separate procedure) |
| 95940 | CPT | Continuous intraoperative neurophysiology monitoring in the operating room, one-on-one monitoring |
| 95941 | CPT | Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby) |
| 95955 | CPT | Electroencephalogram (EEG) during non-intracranial surgery (e.g., carotid) |
Other CPT Codes Related to CPB 0289 (Associated Procedures — Coverage Governed by Separate Policies)
These codes appear in CPB 0289 as contextually related intracranial and neurological surgical procedures. They are not independently covered under this bulletin's selection criteria.
| Code | Type | Description |
|---|---|---|
| 31200–31230 | CPT | Intracranial vascular surgical procedures (series) |
| 61000–61041 | CPT | Intracranial vascular surgical procedures (series) |
Note: The full policy lists over 1,000 additional related CPT codes in this category. Review the complete CPB 0289 bulletin on the Aetna provider portal for the full code set.
HCPCS Codes
The policy data for CPB 0289 does not list specific HCPCS codes. No HCPCS codes are covered or excluded under this bulletin.
Key ICD-10-CM Diagnosis Codes
The policy data for CPB 0289 references ICD-10-CM codes but does not publish the specific codes in the publicly available bulletin summary. Pull the complete CPB 0289 document from the Aetna provider portal to confirm which diagnosis codes support medical necessity for each covered CPT code. Do not submit claims without verifying ICD-10 linkage against the full policy.
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