CPT 90656: Monitorização Neurofisiológica Intraoperatória – Essenciais de Codificação

CPT 90656 reports continuous intraoperative neurophysiological monitoring (IONM)—such as EEG, EMG, and evoked potentials—during a surgical procedure, billed in 15-minute increments. This service is critical for detecting neural injury in real time during high-risk operations.

Key Coding Points

• Time-based billing: 1 unit = 15 minutes of monitoring (8–22 minutes = 1 unit; 23–37 minutes = 2 units, etc.).
• Covered modalities: Somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), brainstem auditory evoked potentials (BAEP), visual evoked potentials (VEP), free-run and triggered EMG, EEG, and electrocorticography (ECoG).
• Provider requirements: Typically performed by a neurophysiologist (MD/DO) or a technologist under direct physician supervision.
• Documentation must include: Modalities used, baseline readings, any changes observed, interventions taken, and communication with the surgical team.

Common Surgical Procedures Requiring IONM

• Spinal surgery: deformity correction (scoliosis), tumor resection, decompression.
• Cranial surgery: tumor resection, arteriovenous malformation (AVM) clipping, epilepsy surgery.
• Vascular surgery: Carotid endarterectomy, aortic arch procedures.
• Peripheral nerve surgery.

Billing & Compliance Notes

• IONM is billed separately from the surgeon's professional fee.
• Use modifier -26 (professional component) if the technical component (equipment/technologist) is billed separately by the facility.
• Not reportable for postoperative monitoring in the recovery room or ICU.
• Ensure medical necessity is supported by the surgical risk to neural structures.