Aetna modified CPB 0387 covering magnetic resonance neurography, effective September 26, 2025. Here's what billing teams need to know.
Aetna, a CVS Health company, updated Clinical Policy Bulletin 0387, which governs the Aetna magnetic resonance neurography coverage policy. The policy applies to nerve, nerve root, and plexus disorders (ICD-10 G50.0–G59) and nerve/spinal cord injuries across a wide range of S-series trauma codes. If your practice bills magnetic resonance neurography for neurology, orthopedics, spine, or pain management patients, this update deserves your attention before claims go out the door.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Aetna |
| Policy | Magnetic Resonance Neurography — CPB 0387 |
| Policy Code | CPB 0387 |
| Change Type | Modified |
| Effective Date | September 26, 2025 |
| Impact Level | Medium |
| Specialties Affected | Neurology, orthopedic surgery, spine surgery, pain management, radiology |
| Key Action | Audit active MRN claims and confirm ICD-10 codes align with G50.0–G59 or the applicable S-series nerve injury codes before submitting |
Aetna Magnetic Resonance Neurography Coverage Criteria and Medical Necessity Requirements 2025
Magnetic resonance neurography (MRN) is a specialized MRI technique that images peripheral nerves directly. Aetna's coverage policy under CPB 0387 Aetna system ties reimbursement to documented medical necessity — and that's where most claim denial risk lives with this procedure.
The policy recognizes two broad diagnostic categories. The first is nerve, nerve root, and plexus disorders coded under ICD-10-CM G50.0 through G59. This range covers trigeminal neuralgia, facial nerve disorders, brachial plexus lesions, thoracic outlet syndrome, lumbosacral root disorders, mononeuropathies of the upper and lower limbs, and unspecified mononeuropathies — a wide but specific set of diagnoses.
The second category covers traumatic nerve and spinal cord injuries. Aetna's policy maps these to an extensive set of S-series ICD-10 codes spanning cranial nerve injuries (S04.011A–S04.9xxS), cervical spinal cord injuries (S14.0xxA–S14.9xxS), thoracic spinal cord injuries (S24.0xxA–S24.9xxS), lumbar and sacral spinal cord injuries (S34.01xA–S34.9xxS), and peripheral nerve injuries at the shoulder, upper arm, elbow, forearm, wrist/hand, hip, thigh, knee, lower leg, and ankle/foot levels across the S44, S54, S64, S74, S84, and S94 code families.
Medical necessity documentation needs to support why conventional MRI or other imaging was insufficient. Your ordering providers should spell that out in the clinical notes. Vague documentation is the fastest path to a claim denial on MRN.
The policy does not list a blanket prior authorization requirement in the data provided, but Aetna plans frequently impose prior authorization at the plan level for advanced imaging. Verify prior auth requirements against the member's specific plan before scheduling the study. If you're not sure, call the plan or check the member's eligibility record — don't assume.
Aetna Magnetic Resonance Neurography Exclusions and Non-Covered Indications
The policy data does not enumerate specific experimental or non-covered indications within the code set provided. That said, Aetna's broader coverage policy posture on advanced imaging procedures typically treats MRN as investigational when used outside established diagnostic indications.
The real issue here is the gap between what the ICD-10 code set technically allows and what Aetna will actually pay. Using a G-range or S-range code doesn't guarantee coverage. The clinical documentation still has to justify why MRN — rather than standard MRI or electrodiagnostic studies — was the right tool for that specific patient.
If your practice is ordering MRN for conditions that fall outside G50.0–G59 or the listed S-series injury codes, expect denials. Build that filter into your pre-authorization workflow now, before September 26, 2025 claims start moving through your billing system.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Nerve, nerve root, and plexus disorders | Covered (when medically necessary) | G50.0–G59 | Includes trigeminal neuralgia, brachial plexopathy, lumbosacral root disorders, mononeuropathies |
| Cranial nerve injuries (traumatic) | Covered (when medically necessary) | S04.011A–S04.9xxS | All episode qualifiers included (initial, subsequent, sequela) |
| Cervical spinal cord injuries | Covered (when medically necessary) | S14.0xxA–S14.9xxS | Full injury range, all episode qualifiers |
| Thoracic spinal cord injuries | Covered (when medically necessary) | S24.0xxA–S24.9xxS | Full injury range, all episode qualifiers |
| Lumbar/sacral spinal cord injuries | Covered (when medically necessary) | S34.01xA–S34.9xxS | Full injury range, all episode qualifiers |
| Shoulder/upper arm nerve injuries | Covered (when medically necessary) | S44.00xA–S44.92xS | Peripheral nerve injuries at shoulder girdle |
| Elbow/forearm nerve injuries | Covered (when medically necessary) | S54.00xA–S54.92xS | Peripheral nerve injuries at forearm level |
| Wrist/hand nerve injuries | Covered (when medically necessary) | S64.00xA–S64.92xS | Peripheral nerve injuries at wrist and hand |
| Hip/thigh nerve injuries | Covered (when medically necessary) | S74.00A+–S74.92xS | Peripheral nerve injuries at hip and thigh |
| Knee/lower leg nerve injuries | Covered (when medically necessary) | S84.00xA–S84.92xS | Peripheral nerve injuries at lower leg |
| Ankle/foot nerve injuries | Covered (when medically necessary) | S94.00xA–S94.92xS | Peripheral nerve injuries at ankle and foot |
| MRN outside listed G or S code ranges | Not Covered / Likely Denied | — | No coverage basis in CPB 0387 for diagnoses outside these ranges |
Aetna Magnetic Resonance Neurography Billing Guidelines and Action Items 2025
Magnetic resonance neurography billing carries more documentation risk than standard MRI billing. The diagnosis code has to do real work here — it's not just an administrative box. Here's what your billing team needs to do before and after the September 26, 2025 effective date.
| # | Action Item |
|---|---|
| 1 | Audit your active MRN charge capture now. Pull any queued or recent MRN claims and confirm the primary diagnosis code maps to G50.0–G59 or one of the S-series nerve injury code families listed in CPB 0387. Claims with diagnosis codes outside these ranges are denial candidates under the updated policy. |
| 2 | Check for prior authorization at the plan level before every MRN order. CPB 0387 doesn't mandate prior auth universally, but many Aetna commercial and managed care plans layer their own prior authorization requirements on top of the clinical policy. Build a plan-level PA check into your scheduling workflow — not just an eligibility check. |
| 3 | Require specific clinical justification in every MRN order. The ordering provider's notes should state why standard MRI or electrodiagnostic testing (EMG/NCS) was insufficient or inconclusive. Generic language like "patient has nerve pain" won't carry a medical necessity review. The documentation should name the specific nerve or plexus suspected and explain the clinical question MRN is meant to answer. |
| 4 | Train your coders on the S-series code structure for nerve injuries. The S-series codes in CPB 0387 span multiple anatomical levels and include encounter qualifiers (A for initial, D for subsequent, S for sequela). The wrong encounter qualifier on a trauma-related MRN claim is a fixable error that will still get you denied. Verify coder familiarity with 7th-character extension rules before claims go out. |
| 5 | Set up a denial tracking flag for CPB 0387 claims. If you see denials citing "not medically necessary" or "not covered" on MRN claims after September 26, 2025, capture those systematically. A pattern of denials on a specific diagnosis range — say, G54 lumbosacral plexus disorders — tells you there may be a coverage criteria gap or a documentation problem your team needs to address. |
| 6 | Talk to your compliance officer if your practice uses MRN broadly. If MRN is a high-volume service for your specialty — particularly in neurology, orthopedic surgery, or interventional pain — have your compliance officer review your ordering patterns against the G50.0–G59 and S-series code list. Consistent use of MRN for diagnoses outside these ranges is a reimbursement and audit risk worth addressing proactively. |
| 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 Magnetic Resonance Neurography Under CPB 0387
The policy data provided for CPB 0387 does not list specific CPT or HCPCS procedure codes. Aetna's Clinical Policy Bulletin defines coverage in terms of ICD-10-CM diagnosis codes rather than procedure codes for this service. Magnetic resonance neurography billing typically uses MRI CPT codes — confirm the exact procedure codes with your radiology billing team and verify how Aetna maps those codes to this policy.
Key ICD-10-CM Diagnosis Codes
| Code Range | Description |
|---|---|
| G50.0–G59 | Nerve, nerve root, and plexus disorders |
| S04.011A–S04.9xxS | Injury to cranial nerves |
| S14.0xxA–S14.9xxS | Injury to cervical spinal cord and nerves |
| S24.0xxA–S24.9xxS | Injury to thoracic spinal cord and nerves |
| S34.01xA–S34.9xxS | Injury to lumbar and sacral spinal cord and nerves |
| S44.00xA–S44.92xS | Injury to nerves at shoulder and upper arm level |
| S54.00xA–S54.92xS | Injury to nerves at forearm level |
| S64.00xA–S64.92xS | Injury to nerves at wrist and hand level |
| S74.00A+–S74.92xS | Injury to nerves at hip and thigh level |
| S84.00xA–S84.92xS | Injury to nerves at lower leg level |
| S94.00xA–S94.92xS | Injury to nerves at ankle and foot level |
All S-series codes cover initial encounters (A), subsequent encounters (D), and sequelae (S) where applicable. Code selection must match the actual encounter type — using an "A" code on a follow-up visit or a "D" code on an initial post-surgical assessment are errors that generate denials and corrected-claim work.
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