CurrentAmbetter NevadaPolicy CC.PP.503

Intraoperative Neurophysiology Monitoring (IONM) - Reimbursement Policy

Defines Centene/Ambetter Nevada reimbursement and billing rules for continuous intraoperative neurophysiology monitoring (IONM) across Medicare Advantage, Marketplace, and Medicaid products, subject to state-specific Medicaid requirements and member benefit documents.

Policy Summary

PayerAmbetter Nevada

PolicyIntraoperative Neurophysiology Monitoring (IONM) - Reimbursement Policy

Policy CodePolicy CC.PP.503

Change TypeNo material change

Effective DateJun 1, 2026

Next Review Date

Key ActionBill IONM services using CMS-recognized payable codes (+95940 or +G0453) with exclusive one-to-one monitoring, in 15-minute increments, and no more than four units per 60 minutes.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

2primary payable procedure codes referenced

4maximum units per 60 min

19,21,22,24required places of service

CMS-alignedMarketplace alignment

Coverage criteria for continuous IONM

Reimbursement is allowed only when CMS-recognized payable codes and ALL of the following criteria are met. Services that do not meet these criteria are not covered.

ALL of the following

ALL of the following
- CPT +95940 must be used when monitoring is performed in the operating room with one-to-one monitoring; reported in 15-minute increments
  CPT +95940 is a payable code for continuous OR one-to-one monitoring
- HCPCS +G0453 must be used for continuous remote IONM requiring exclusive attention to one patient; reported in 15-minute increments
  HCPCS +G0453 is a payable code for continuous remote monitoring
EXCLUDED CODES

Policy Summary

PayerAmbetter Nevada

PolicyIntraoperative Neurophysiology Monitoring (IONM) - Reimbursement Policy

Policy CodePolicy CC.PP.503

Change TypeNo material change

Effective DateJun 1, 2026

Next Review Date

Key ActionBill IONM services using CMS-recognized payable codes (+95940 or +G0453) with exclusive one-to-one monitoring, in 15-minute increments, and no more than four units per 60 minutes.

SourceLink

On This Page

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Payable codes, units, and reporting increments

Covered IONM CodesCPT | HCPCSCovered

95940	Continuous IONM performed in the operating room with one-to-one monitoring, each 15 minutes
G0453	Continuous remote IONM requiring exclusive attention to one patient, reported in 15-minute increments

Non-covered / Excluded IONM CodesCPTNot Covered

95941

Continuous IONM performed remotely or for concurrent monitoring of more than one case.

Maximum units per hour

Maximum units per 60-minute periodNo more than four (4) units may be billed per 60-minute period

Billing relation to monitoring timeTotal units billed must not exceed the total monitoring time available

Unit cap rationaleAligned to CMS time-based billing guidance for continuous IONM

Unit reporting increments

Unit incrementsReported in 15-minute increments

Code examples using incrementsCPT +95940 and HCPCS +G0453 are reported in 15-minute increments

Relation to total unitsUnits reported in 15-minute increments must not cause total billed units to exceed monitoring time

Billing and provider requirements for IONM

Billing Rule

Billing and provider requirements for IONM

Bill continuous IONM only with CMS-recognized payable codes +95940 or +G0453, reported in 15-minute increments and in addition to the primary surgical procedure code; follow CMS time‑based reporting rules and report appropriate modifiers, units, and Place of Service (POS 19, 21, 22, or 24). Ensure monitoring is exclusive, one-to-one (undivided attention to one patient), limit billing to no more than four units per 60-minute period, and do not bill the service by the surgeon or anesthesia provider (it is included in the global surgical package). Failure to follow these billing and provider requirements risks claim denial or nonpayment.

Use CPT +95940 or HCPCS +G0453 and bill in 15-minute increments.
Bill IONM in addition to the primary surgical procedure code and comply with CMS time-based reporting rules.
Do not bill more than four (4) units per 60-minute period; total units must not exceed monitoring time.
Provide exclusive, undivided attention to one patient (one-to-one monitoring).
Do not bill the service by the surgeon or anesthesia provider; use appropriate Place of Service (POS 19, 21, 22, or 24).
Report current and appropriate codes, modifiers, units, and POS per CMS, CPT, and HCPCS guidance to avoid denials.

Key definitions and terms

CMS-recognized payable codes

DefinitionCMS-recognized payable codes: procedure codes that CMS recognizes and permits for payment for IONM services (e.g., +95940, +G0453)

Billing requirementServices must be billed using CMS-recognized payable codes for Medicare Advantage, Marketplace, and Medicaid unless state Medicaid rules supersede

Non-payable consequenceServices billed with codes not recognized or payable under CMS guidance are not eligible for reimbursement

One-to-one monitoring requirement

Exclusive, undivided attentionMonitoring must be performed with exclusive, undivided attention to one patient (one-to-one monitoring)

Operational implicationIONM personnel must not concurrently monitor multiple cases or patients during the billed time period

Relation to billing codesOne-to-one monitoring is a requirement for billing CMS-recognized IONM codes such as +95940 and +G0453