ModifiedKaiser PermanentePolicy N/A

Clinical Review Criteria Intraoperative Neurophysiological Monitoring (IONM)

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Medical-necessity criteria, professional billing requirements, and experimental or investigational exclusions for intraoperative neurophysiological monitoring, including SSEP/MEP, EEG, and EMG, for Kaiser Permanente Washington members and providers.

Policy Summary

PayerKaiser Permanente

PolicyIntraoperative Neurophysiological Monitoring (IONM)

Policy CodePolicy N/A

Change TypeModified

Effective DateJanuary 1, 2027

Last ReviewApr 7, 2026

Next Review DateN/A

Key ActionSubmit professional IONM charges on a HCFA 1500 claim form; UB-form charges are not reimbursable.

SourceLink

POLICY UPDATE CHANGES

Effective January 1, 2027, the eligible procedure criteria and modality-specific indications for IONM were revised and expanded.

The 2027 criteria add SSEP/MEP consideration for peripheral brachial plexus neuroma excision, nerve-traction leg-lengthening procedures, traumatic brain injury surgery, and bronchial artery AVM or tumor embolization.

The 2027 criteria add EEG consideration for basal ganglia procedures for movement disorders and surgery resulting from traumatic brain injury.

The 2027 criteria add EMG consideration for basal ganglia movement-disorder procedures, cavernous sinus tumor resection, foramen magnum procedures, and cochlear implant surgery.

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ModifiedKaiser PermanentePolicy N/A

Clinical Review Criteria Intraoperative Neurophysiological Monitoring (IONM)

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Policy Summary

PayerKaiser Permanente

PolicyIntraoperative Neurophysiological Monitoring (IONM)

Policy CodePolicy N/A

Change TypeModified

Effective DateJanuary 1, 2027

Last ReviewApr 7, 2026

Next Review DateN/A

Key ActionSubmit professional IONM charges on a HCFA 1500 claim form; UB-form charges are not reimbursable.

SourceLink

POLICY UPDATE CHANGES

Effective January 1, 2027, the eligible procedure criteria and modality-specific indications for IONM were revised and expanded.

The 2027 criteria add EEG consideration for basal ganglia procedures for movement disorders and surgery resulting from traumatic brain injury.

The 2027 criteria add EMG consideration for basal ganglia movement-disorder procedures, cavernous sinus tumor resection, foramen magnum procedures, and cochlear implant surgery.

3IONM modalities addressed

3 maxSimultaneous cases per monitoring physician

Once per sessionBaseline testing limit

3Experimental modalities for all indications

9Codes considered not medically necessary

Medical Necessity and Coverage Criteria

General criteria

All general operational criteria must be met for non-Medicare members.

General operational requirements

IONM is performed by a licensed physician trained in clinical neurophysiology, or by a trained technologist practicing within the scope of licensure or certification and working under the direct supervision of a physician trained in neurophysiology.
IONM is interpreted by a licensed physician trained in clinical neurophysiology, other than the operating surgeon, who is in the operating suite or available through a real-time remote monitoring mechanism and immediately available.
Monitoring is conducted and interpreted in real time and is continuously communicated to the surgical team.
The physician performing or supervising monitoring monitors no more than three cases simultaneously.No more than 3 simultaneous cases
Professional IONM charges are billed on a HCFA 1500 claim form.
Charges related to IONM billed on a UB form are not reimbursable.

SSEP with or without MEP

SSEP with or without electrically stimulated MEP may be medically necessary during one or more of the following procedures.

At least 1 eligible procedure

Spinal procedures: Dorsal rhizotomy; correction of scoliosis; correction of deformity involving traction on the spinal cord; spinal cord tumor removal; surgery due to traumatic injury to the spinal cord; or surgery for arteriovenous malformation of the spinal cord.
Peripheral nerve procedures: Excision of neuromas of peripheral nerves of the brachial plexus when there is documented risk to major sensory or motor nerves, or leg-lengthening procedures involving traction on the sciatic nerve or other nerve trunks.
Intracranial procedures: Microvascular decompression of cranial nerves; removal of acoustic neuroma, congenital auricular lesions, or cranial-base lesions; cholesteatoma surgery, including mastoidotomy or mastoidectomy; vestibular neurectomy for Meniere disease; removal of listed cranial-nerve neuromas; deep-brain stimulation; endolymphatic shunting for Meniere disease; oval or round window grafting; cavernous sinus tumor removal; resection of brain tissue near the primary motor cortex requiring brain mapping; resection of epileptogenic brain tissue or tumor; other intracranial procedures such as aneurysm repair or intracranial arteriovenous malformation procedures; or surgery resulting from traumatic injury to the brain.

EEG monitoring

EEG monitoring may be considered medically necessary during one or more of the following procedures.

At least 1 eligible procedure

Intracranial procedures: Basal ganglia procedures for correction of movement disorders; microvascular decompression of cranial nerves; removal of acoustic neuroma, congenital auricular lesions, or cranial-base lesions; cholesteatoma surgery, including mastoidotomy or mastoidectomy; vestibular neurectomy for Meniere disease; removal of listed cranial-nerve neuromas; deep-brain stimulation; endolymphatic shunting for Meniere disease; oval or round window grafting; cavernous sinus tumor removal; resection of brain tissue near the primary motor cortex requiring brain mapping; resection of epileptogenic brain tissue or tumor; other intracranial procedures such as aneurysm repair or intracranial arteriovenous malformation procedures; or surgery resulting from traumatic injury to the brain.
Non-cranial vascular procedures: Carotid artery surgery or arteriography with test occlusion of the carotid artery.

EMG monitoring

EMG monitoring may be considered medically necessary when performed during one or more of the following procedures.

At least 1 eligible procedure

Intracranial procedures: Basal ganglia procedures for correction of movement disorders; cavernous sinus tumor resection; dorsal rhizotomy; microvascular decompression of cranial nerves; removal of acoustic neuroma, congenital auricular lesions, cranial-base lesions, or foramen-magnum lesions; cholesteatoma surgery, including mastoidotomy or mastoidectomy; cochlear implant surgery; vestibular neurectomy for Meniere disease; removal of listed cranial-nerve neuromas; endolymphatic shunting for Meniere disease; or oval or round window grafting.

Experimental and investigational indications

IONM is experimental and investigational when the indication does not meet the listed criteria.

Insufficient-evidence indication: Examples include routine lumbar or cervical laminectomies and fusions, spinal cord stimulator implantation, thyroid or parathyroid surgery, vagal nerve stimulator implantation, spinal injections, hip replacement, and parotid gland surgery.Any listed example or other indication not meeting criteria

The examples are not exhaustive.

Procedures eligible for consideration of IONM

IONM is considered medically necessary when the applicable procedure and modality-specific criteria are met.

Spinal procedures: Dorsal rhizotomy; correction of scoliosis; correction of deformity involving traction on the spinal cord; spinal cord tumor removal; surgery due to traumatic injury to the spinal cord; or surgery for spinal cord arteriovenous malformation.

The source table identifies applicability separately for SSEP with or without MEP, EEG, and EMG.

Non-spinal procedures: Brachial plexus neuroma excision, when there is documented risk to major sensory or motor nerves, and leg-lengthening procedures involving nerve traction.

The source table identifies applicability separately for SSEP with or without MEP, EEG, and EMG.

Non-cranial vascular procedures: Carotid artery surgery; arteriography with test occlusion; bronchial artery arteriovenous malformation or tumor embolization; deep hypothermic circulatory arrest; distal aortic procedures due to risk of spinal cord ischemia; and surgery of the aortic arch, its branch vessels, or thoracic aorta.

The source table identifies applicability separately for SSEP with or without MEP, EEG, and EMG.

Experimental and investigational services

IONM is experimental and investigational for all indications not meeting the applicable criteria.

Experimental or investigational IONM

IONM is experimental and investigational for routine lumbar or cervical laminectomies and fusions, spinal cord stimulator implantation, thyroid or parathyroid surgery, vagal nerve stimulator implantation, spinal injections, hip replacement, parotid gland surgery, and other indications that do not meet the policy criteria.
The listed procedures are examples and are not exhaustive.
Intraoperative visual evoked-potential monitoring, intraoperative motor-evoked-potential monitoring using transcranial magnetic stimulation, and nerve-conduction studies for intraoperative monitoring are experimental and investigational for all indications.

IONM is experimental and investigational for indications that do not meet the applicable coverage criteria. Examples include routine lumbar or cervical laminectomies and fusions, spinal cord stimulator implantation, thyroid or parathyroid surgery, cochlear implantation, vagal nerve stimulator implantation, spinal injections, hip replacement, and parotid gland surgery. These examples are not exhaustive.

Intraoperative visual evoked-potential monitoring is experimental and investigational for all indications.

Intraoperative motor-evoked-potential monitoring using transcranial magnetic stimulation is experimental and investigational for all indications.

Nerve-conduction studies performed for intraoperative monitoring are experimental and investigational for all indications.

The following are examples of procedures for which there is insufficient evidence to establish the net benefit of IONM and are considered experimental and investigational: routine lumbar or cervical laminectomies and fusions, spinal cord stimulator implantation, thyroid or parathyroid surgery, vagal nerve stimulator implantation, spinal injections, hip replacement, and parotid gland surgery. The examples are not exhaustive.

Intraoperative visual evoked-potential monitoring is experimental and investigational for all indications; no procedure-specific exception is identified in this policy.

Intraoperative motor-evoked-potential monitoring using transcranial magnetic stimulation is experimental and investigational for all indications; no procedure-specific exception is identified in this policy.

Nerve-conduction studies used for intraoperative monitoring are experimental and investigational for all indications; no procedure-specific exception is identified in this policy.

The following CPT codes are considered not medically necessary: 95907–95913 for nerve-conduction studies, 95930 for visual evoked-potential testing, and 95937 for neuromuscular-junction testing.

Covered and Noncovered Codes

SSEP with or without MEPCPTCovered

95925	SSEP with or without MEP
95926	SSEP with or without MEP
95927	SSEP with or without MEP
95938	SSEP with or without MEP
95928	SSEP with MEP
95929	SSEP with MEP
95939	SSEP with MEP

EEGCPTCovered

95822	EEG
95955	EEG

EMGCPTCovered

95860	EMG
95861	EMG
95867	EMG
95868	EMG
95870	EMG

General NeuromonitoringCPT | HCPCSCovered

95940	Continuous intraoperative neurophysiology monitoring in the operating room, one on one monitoring requiring personal attendance, each 15 minutes (List separately in addition to code for primary procedure).
95941	Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby) or for monitoring of more than one case while in the operating room, per hour (List separately in addition to code for primary procedure).
G0453	Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby), per patient, attention directed exclusively to one patient, each 15 minutes (list in addition to primary procedure).

Somatosensory-evoked potentials (SSEP)CPTCovered

95925	Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in upper limbs.
95926	Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in lower limbs.
95927	Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in the trunk or head.
95938	Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in upper and lower limbs.

Motor evoked potentials (MEP)CPTCovered

95928	Central motor evoked potential study (transcranial motor stimulation); upper limbs.
95929	Central motor evoked potential study (transcranial motor stimulation); lower limbs.
95939	Central motor evoked potential study (transcranial motor stimulation); in upper and lower limbs.

ElectroencephalographyCPTCovered

95822	Electroencephalogram (EEG); recording in coma or sleep only.
95955	Electroencephalogram (EEG) during nonintracranial surgery (eg, carotid surgery).

ElectromyographyCPTCovered

95860	Needle electromyography; 1 extremity with or without related paraspinal areas.
95861	Needle electromyography; 2 extremities with or without related paraspinal areas.
95867	Needle electromyography; cranial nerve supplied muscle(s), unilateral.
95868	Needle electromyography; cranial nerve supplied muscles, bilateral.
95870	Needle electromyography; limited study of muscles in 1 extremity or non-limb (axial) muscles (unilateral or bilateral), other than thoracic paraspinal, cranial nerve supplied muscles, or sphincters.

Considered not medically necessaryCPTNot Covered

95907	Nerve conduction studies; 1-2 studies.
95908	Nerve conduction studies; 3-4 studies.
95909	Nerve conduction studies; 5-6 studies.
95910	Nerve conduction studies; 7-8 studies.
95911	Nerve conduction studies; 9-10 studies.
95912	Nerve conduction studies; 11-12 studies.
95913	Nerve conduction studies; 13 or more studies.
95930	Visual evoked potential (VEP) checkerboard or flash testing, central nervous system except glaucoma, with interpretation and report.
95937	Neuromuscular junction testing (repetitive stimulation, paired stimuli), each nerve, any 1 method.

Review, Documentation, and Billing Requirements

Documentation Required

Medicare Medical-Necessity Review

For Medicare members, IONM services require medical-necessity review. The Noridian LCD for Sensory Evoked Potentials & Intraoperative Neurophysiology Monitoring (L34072) is retired, but its criteria should still be referenced for an initial decision. If appealed, do not specifically cite the retired LCD; medical judgment may instead be supported by applicable commercial criteria or a literature search.

Documentation Required

Qualified Personnel and Supervision

IONM must be performed by qualified personnel and interpreted by a qualified physician. The monitoring professional must meet applicable licensure, certification, training, and scope-of-practice requirements, and the interpreting physician must be trained in clinical neurophysiology and be other than the operating surgeon.

A licensed physician trained in clinical neurophysiology may perform monitoring, or a trained technologist may do so within the scope of the technologist’s license or certification and under the direct supervision of a physician trained in neurophysiology.
Interpretation must be by a licensed physician trained in clinical neurophysiology who is in the operating suite or available through a real-time remote mechanism and immediately available.

Intraoperative Neuromonitoring Overview

Intraoperative neurophysiological monitoring (IONM) is used during selected spinal, intracranial, and vascular procedures to monitor neural function in real time and communicate changes to the surgical team. The monitoring modality is selected according to the procedure and may include somatosensory-evoked potentials with or without electrically stimulated motor-evoked potentials, electroencephalography, or electromyography.

IONM Modalities

SSEP/MEP

DefinitionSomatosensory-evoked potentials (SSEP), with or without motor-evoked potentials (MEP), used for intraoperative neuromonitoring.

MEP stimulationWhen MEP is included, the policy specifies electrical stimulation.

UseMay be medically necessary during specified spinal, intracranial, and non-cranial vascular procedures.

EEG Monitoring

DefinitionIntraoperative electroencephalographic (EEG) monitoring.

Intracranial usesMay be considered medically necessary during procedures including basal ganglia surgery for movement disorders, microvascular decompression, acoustic neuroma or cranial-base lesion removal, cholesteatoma surgery, vestibular neurectomy, deep brain stimulation, cavernous sinus tumor removal, brain mapping, epileptogenic tissue or tumor resection, and other intracranial procedures such as aneurysm repair or intracranial AVM surgery.

Policy Summary

PayerKaiser Permanente

PolicyIntraoperative Neurophysiological Monitoring (IONM)

Policy CodePolicy N/A

Change TypeModified

Effective DateJanuary 1, 2027

Last ReviewApr 7, 2026

Next Review DateN/A

Key ActionSubmit professional IONM charges on a HCFA 1500 claim form; UB-form charges are not reimbursable.

SourceLink

On This Page

Non-cranial vascular procedures: Carotid artery surgery; arteriography with test occlusion of the carotid artery; deep hypothermic circulatory arrest; distal aortic procedures; surgery of the aortic arch, its branch vessels, or thoracic aorta; or embolization of bronchial artery arteriovenous malformations or tumors.

Intracranial procedures: Basal ganglia surgery; foramen magnum surgery; microvascular decompression of cranial nerves; removal of acoustic neuroma, congenital auricular lesions, or cranial-base lesions; cholesteatoma surgery, including mastoidotomy or mastoidectomy; vestibular neurectomy for Meniere disease; removal of cranial-nerve neuromas; deep-brain stimulation; endolymphatic shunting for Meniere disease; removal of cavernous sinus tumors; resection of brain tissue near the primary motor cortex requiring brain mapping; resection of epileptogenic tissue requiring brain mapping; surgery for traumatic brain injury; and other intracranial vascular procedures such as aneurysm repair or intracranial arteriovenous malformation surgery.

The source table identifies applicability separately for SSEP with or without MEP, EEG, and EMG; the table text does not support reconstructing every individual modality assignment.

Documentation Required

Real-Time Monitoring Documentation

Monitoring must be conducted and interpreted continuously in real time, either on-site or remotely, with findings communicated continuously to the surgical team. The supervising or performing physician must be able to provide immediate clinical interpretation and response.

Real-time remote monitoring is permitted only when the physician is immediately available through the remote mechanism.
The physician performing or supervising monitoring may monitor no more than three cases simultaneously.

Billing Rule

Baseline Testing Limit

Pre-procedural baseline testing may be separately reported, but it may be reported no more than once per operative session.

Apply the one-baseline-testing limit to the operative session, including procedures covered under the policy’s effective-period criteria.

Billing Rule

Claim Submission

Professional charges for intraoperative monitoring are reimbursable only when submitted on a HCFA 1500 claim form.

Submit professional IONM charges on a HCFA 1500 claim form.

Documentation Required

Medical Necessity Documentation

When requesting IONM, submit documentation sufficient to support medical necessity and the applicable indication.

Last six months of clinical notes from the requesting provider and/or specialist.
Last six months of radiology documentation, if applicable.

Denial Risk

Unlisted or Experimental IONM

IONM is experimental and investigational for indications that do not meet the policy criteria. The following modalities are also experimental and investigational for all indications.

Visual evoked-potential monitoring.
Motor-evoked-potential monitoring using transcranial magnetic stimulation.
Nerve-conduction studies performed for intraoperative monitoring purposes.
Examples of procedures with insufficient evidence to establish net benefit include routine lumbar or cervical laminectomies and fusions, spinal cord stimulator implantation, thyroid or parathyroid surgery, cochlear implantation, vagal nerve stimulator implantation, spinal injections, hip replacement, and parotid gland surgery.

Denial Risk

Incorrect Claim Form

Charges billed on a UB form are not reimbursable. Professional IONM charges must be submitted on a HCFA 1500 claim form.

Do not submit professional intraoperative monitoring charges on a UB claim form.

Denial Risk

Unqualified or Conflicted Monitoring Personnel

Use personnel who satisfy the policy’s licensure, certification, training, supervision, and interpretation requirements. The interpreting physician must be trained in clinical neurophysiology and must not be the operating surgeon.

Technologists must practice within the scope of their state license or certification and work under the direct supervision of a physician trained in neurophysiology.
The interpreting physician must be on-site or immediately available through real-time remote monitoring.
Do not use a physician who is monitoring or supervising more than three cases simultaneously.

Denial Risk

Failure to Meet Real-Time or Staffing Limits

Failure to provide continuous real-time monitoring, continuous communication with the surgical team, qualified supervision, or compliance with the simultaneous-case limit creates denial risk.

Monitoring and interpretation must occur continuously and in real time, on-site or remotely.
Findings must be continuously communicated to the surgical team.
The performing or supervising physician may monitor no more than three cases simultaneously.

Denial Risk

Indication Does Not Meet IONM Criteria

IONM may be medically necessary only when the indication meets the policy criteria. Services for procedures outside those criteria are subject to denial as not medically necessary or experimental and investigational.

Examples that generally do not meet the criteria include routine lumbar or cervical laminectomies and fusions, spinal cord stimulator implantation, thyroid or parathyroid surgery, cochlear implantation, vagal nerve stimulator implantation, spinal injections, hip replacement, and parotid gland surgery.
Document the qualifying spinal, intracranial, vascular, peripheral-nerve, or other covered indication and the specific monitoring modality requested.

Denial Risk

Experimental Monitoring Modality

The following monitoring modalities are excluded as experimental and investigational for all indications and should not be billed as covered IONM.

Intraoperative visual evoked-potential monitoring.
Intraoperative motor-evoked-potential monitoring using transcranial magnetic stimulation.
Nerve-conduction studies for intraoperative monitoring purposes.

Denial Risk

Not Medically Necessary Codes

The following codes are considered not medically necessary under the policy. Coverage may also be affected by code status at the time of service and by plan-specific authorization requirements.

CPT 95907 — Nerve conduction studies; 1–2 studies.
CPT 95908 — Nerve conduction studies; 3–4 studies.
CPT 95909 — Nerve conduction studies; 5–6 studies.
CPT 95910 — Nerve conduction studies; 7–8 studies.
CPT 95911 — Nerve conduction studies; 9–10 studies.
CPT 95912 — Nerve conduction studies; 11–12 studies.
CPT 95913 — Nerve conduction studies; 13 or more studies.
CPT 95930 — Visual evoked potential (VEP) checkerboard or flash testing, central nervous system except glaucoma, with interpretation and report.
CPT 95937 — Neuromuscular junction testing (repetitive stimulation, paired stimuli), each nerve, any one method.
Codes may not be all-inclusive; deleted codes and codes not in effect on the date of service may not be covered. Verify authorization requirements using the plan’s Pre-authorization Code Check.

Denial Risk

Mutually Exclusive Limb-Monitoring Codes

Do not bill mutually exclusive limb-monitoring codes together when both upper and lower limbs are monitored. Use the combined-limb code specified by the policy instead.

Do not bill CPT 95925 and CPT 95926 during the same procedure when both upper and lower limbs are monitored; use CPT 95938 instead.
Do not code CPT 95938 in conjunction with CPT 95925 or CPT 95926.
Do not bill CPT 95928 and CPT 95929 together when both upper and lower limbs are monitored; use CPT 95939 instead.

Non-cranial vascular usesMay be considered medically necessary during carotid artery surgery and arteriography with test occlusion of the carotid artery.

EMG Monitoring

DefinitionIntraoperative electromyographic (EMG) monitoring.

Specified proceduresMay be considered medically necessary during listed procedures including basal ganglia surgery for movement disorders, cavernous sinus tumor resection, dorsal rhizotomy, microvascular decompression, and acoustic neuroma, congenital auricular, cranial-base, or foramen-magnum procedures.

Additional usesThe listed procedures also include cholesteatoma surgery, cochlear implant surgery, vestibular neurectomy for Meniere's disease, cranial-nerve neuroma removal, endolymphatic shunt, and oval or round window grafting.