CurrentCentenePolicy CP MP.203

Clinical Policy: Diaphragmatic/Phrenic Nerve Stimulation

Defines medical necessity criteria for diaphragmatic/phrenic nerve stimulation devices (Avery Mark IV and Spirit systems, NeuRx RA/4) including indications, required physiologic findings, age/FVC constraints for NeuRx per HDE/DFU, and states that other uses (e.g., central apnea) are insufficiently supported.

Policy Summary

PayerCentene

PolicyClinical Policy: Diaphragmatic/Phrenic Nerve Stimulation

Policy CodePolicy CP MP.203

Change TypeRevision / Coding update

Effective Date

Next Review Date

Key ActionDocument visible diaphragm movement with stimulation by fluoroscopy or ultrasound and intact phrenic nerve/diaphragm/lung function; ensure NeuRx use follows HDE/FDA conditions and prior authorization requirements.

POLICY UPDATE CHANGES

Criteria I updated to include the Spirit Diaphragm Pacing Transmitter and background updated to include full FDA approval information for Spirit.

Added codes L8685-L8688 to HCPCS codes table.

Updated NeuRx RA/4 background to include full FDA approval and added Remede System section.

2Primary covered indications (Avery)

2NeuRx covered indications (ALS, spinal cord injury)

1Not covered: other conditions (including central apnea)

Coverage Summary

Policy Number: CP MP.203; Status: CURRENT; Last review: 07/25.

Overview: Diaphragmatic/phrenic nerve stimulation (diaphragm pacing) is a therapy that uses electrical stimulation of the phrenic nerves or diaphragm to produce rhythmic diaphragmatic contractions to reduce or eliminate the need for mechanical ventilator support in patients with chronic ventilatory insufficiency from bilateral diaphragmatic paralysis or severe paresis. Devices covered by this policy include the Avery Mark IV (Mark IV Breathing Pacemaker System), the Spirit Diaphragm Pacing Transmitter, and the NeuRx RA/4 Diaphragm Pacing System when used according to the specified criteria. Other uses, including application of systems such as the Remede System for central sleep apnea, are considered to have insufficient evidence to establish safety and efficacy and are therefore not supported by this policy.

Policy thresholds and scope summary

Forced Vital Capacity (FVC)>= 45% predicted

Unassisted breathing duration>= 4 continuous hours per day

Primary covered indications (Avery)2

NeuRx covered indications (ALS, spinal cord injury)2

Not covered: other conditions (including central apnea)1

Medical-Necessity Criteria

I. Avery Mark IV or Spirit Diaphragm Pacing Transmitter - Medically Necessary

Covered when ALL of the following are met:

ALL of the following

ONE OF
- Upper cervical spinal cord injury (at or above the C3 vertebral level)
- Central alveolar hypoventilation disorder
Diaphragm movement with stimulation is visible under fluoroscopy.
Stimulation of the diaphragm either directly or through the phrenic nerve results in sufficient muscle activity to accommodate independent breathing without the support of a ventilator.
Intact and sufficient function in the phrenic nerve, lungs, and diaphragm.
Normal chest anatomy, a normal level of consciousness, and the ability to participate in and complete the training and rehabilitation associated with the use of the device.

II. NeuRx RA/4 Diaphragm Pacing System - Medically Necessary per HDE/full FDA specifications

Covered when ALL of the following are met and when provided in accordance with the FDA Humanitarian Device Exemption (HDE) specifications or full FDA approval as applicable:

ALL of the following

Device is the NeuRx RA/4 Diaphragm Pacing System used in accordance with applicable FDA HDE specifications or full FDA labeling for the indication provided.
ONE OF
- Amyotrophic lateral sclerosis (ALS) with a stimulatable diaphragm as demonstrated by voluntary contraction or phrenic nerve conduction studies, and experiencing chronic hypoventilation but not progressed to forced vital capacity (FVC) less than 45% predicted (HDE indication).
- Stable, high cervical spinal cord injury with a stimulatable diaphragm and lack of voluntary control of the diaphragm (FDA HDE or full approval indication).
AGE / FVC CONDITIONS

III. Not Medically Necessary / Insufficient Evidence

Not medically necessary / Insufficient evidence:

ALL of the following

There is insufficient evidence to support the safety and efficacy of diaphragmatic/phrenic nerve stimulation for conditions other than the specific indications listed above.
Diaphragmatic/phrenic nerve stimulation is not covered for other conditions including, but not limited to, central sleep apnea or other sleep-related indications.

Provider Actions

Documentation Required

Document physiologic testing and imaging

Provider must document visible diaphragm movement with stimulation by fluoroscopy or other radiographic techniques (e.g., ultrasound) and document intact phrenic nerve/diaphragm/lung function. Examples of physiologic testing or imaging that can demonstrate stimulatable diaphragm and intact function include phrenic nerve conduction studies, demonstration of voluntary diaphragm contraction, and fluoroscopy or ultrasound visualization of diaphragm movement.

Phrenic nerve conduction studies
Voluntary diaphragm contraction
Fluoroscopy or ultrasound visualization

Documentation Required

Document indication and ventilator dependence

Provider must document that stimulation is being used as an alternative to mechanical ventilation for severe, chronic respiratory failure due to a listed indication and that the individual is ventilator-dependent as applicable. Covered indications include upper cervical spinal cord injury (at or above C3 vertebral level) and central alveolar hypoventilation; NeuRx-specific covered indications include ALS and high spinal cord injury per HDE/full FDA specifications.

Upper cervical spinal cord injury (at or above C3)
Central alveolar hypoventilation
NeuRx: Amyotrophic lateral sclerosis (ALS) and spinal cord injury where specified

Prior Authorization

Prior authorization / HDE compliance

NeuRx RA/4 must be provided in accordance with HDE/FDA-specified conditions and plan prior authorization procedures. For NeuRx ALS indication, patients must meet the HDE age and FVC requirements (age ≥21 years and chronic hypoventilation but not progressed to FVC <45% predicted). For the NeuRx spinal cord injury indication, age criteria per HDE apply (≥18 years). Health plan-specific prior authorization procedures should be followed.

NeuRx ALS age/FVC limits: ≥21 years and FVC not <45% predicted
NeuRx spinal cord injury age limit: ≥18 years for that indication
Device must be provided per HDE/FDA specifications and any plan prior authorization requirements

Coding

Relevant CPT codes (informational)CPT

64575	Open implantation of neurostimulator electrode array; peripheral nerve (excludes sacral nerve)
64580	Open implantation of neurostimulator electrode array; neuromuscular
64590	Insertion or replacement of peripheral, sacral, or gastric neurostimulator generator or receiver, requiring pocket creation and connection between electrode array and pulse generator/receiver
64595	Revision or removal of peripheral, sacral, or gastric neurostimulator generator or receiver, with detachable connection to electrode array/pulse

Relevant HCPCS / Supply codesHCPCS

C1778	Lead, neurostimulator (implantable)
C1816	Receiver and/or transmitter, neurostimulator (implantable)
L8680	Implantable neurostimulator electrode, each
L8681	Patient programmer (external) for use with implantable programmable neurostimulator pulse generator - replacement only
L8682	Implantable neurostimulator radiofrequency receiver
L8683	Radiofrequency transmitter (external) for use with implantable neurostimulator radiofrequency receiver
L8685	Implantable neurostimulator generator; single array, rechargeable, includes extension pulse
L8686	Implantable neurostimulator generator; single array, nonrechargeable, includes extension pulse
L8687	Implantable neurostimulator pulse generator, dual array, rechargeable, includes extension
L8688	Implantable neurostimulator pulse generator, dual array, nonrechargeable, includes extension

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Background & Evidence

Background: Diaphragmatic/phrenic nerve stimulators are intended for ventilator-dependent individuals who lack voluntary diaphragmatic control and who have sufficient phrenic nerve, lung, and diaphragm function to respond to electrical stimulation. Examples of commercially available systems include the Avery Diaphragm Pacing System family (including the Mark IV Breathing Pacemaker System and the Spirit Diaphragm Pacing Transmitter) and the NeuRx RA/4 Diaphragm Pacing System.

Regulatory pathway and approvals: The NeuRx RA/4 system was originally approved under a Humanitarian Device Exemption (HDE) on June 17, 2008 for high spinal cord injury patients and later received HDE authorization for an ALS indication (with age and FVC constraints); NeuRx subsequently received full FDA approval updates noted in 2023. The Avery Spirit Diaphragm Pacing Transmitter received full FDA approval in 2019 for use in patients with functional lungs and diaphragm muscle and an intact phrenic nerve. The NeuRx HDE indication for ALS specifies age and respiratory function constraints (e.g., ALS patients 21 years or older and chronic hypoventilation but not progressed to FVC < 45% predicted), and the NeuRx spinal cord injury HDE indication applies to patients 18 years or older with stimulatable diaphragms who can breathe for at least 4 continuous hours per day with pacing.

Remede System note: Although the Remede System was FDA-cleared for treatment of moderate to severe central sleep apnea in adults (2017), the evidence is considered insufficient to determine safety and effectiveness of diaphragmatic/phrenic nerve stimulation for central apnea or sleep-related indications; additional high-quality studies are recommended.

Evidence summary: NeuRx received initial HDE approval in 2008 with later HDE/approval updates (including 2011 HDE for ALS and full approval updates noted in 2023). The Avery Spirit system obtained full FDA approval in 2019. These regulatory facts and the limited clinical evidence base inform the policy’s criteria and the statement that other indications (including central apnea) lack sufficient evidence for coverage.

Definitions

Chronic hypoventilationA state of chronic ventilatory insufficiency requiring nocturnal or continuous ventilatory support; NeuRx criteria specify patients experiencing chronic hypoventilation but with FVC >= 45% predicted for ALS HDE indication.

HDEHumanitarian Device Exemption — FDA pathway for devices treating conditions affecting fewer than 8,000 individuals/year in the U.S., with specific labeling and use requirements.

Name	Number	Effective Year	Type
Phrenic nerve stimulator	160.19	2025	NCD

Revision History

07/24product/background update

Criteria I updated to include the Spirit Diaphragm Pacing Transmitter; background updated to include information regarding full FDA approval of the Spirit Diaphragm Pacing Transmitter.

07/25product/background updateLatest

Background updated to include information regarding full FDA approval of the NeuRx RA/4 Diaphragm Pacing System and a section added regarding the Remede System (noting insufficient evidence for CSA).

07/25coding updateLatest

Added HCPCS codes L8685, L8686, L8687, L8688 to the HCPCS codes table; coding reviewed.

OpenPayer

Clinical Policy: Diaphragmatic/Phrenic Nerve Stimulation

Coverage Summary

Medical-Necessity Criteria

Provider Actions

Coding

Background & Evidence

Medicare Determinations

Revision History