Summary & Overview
CPT 95829: Electrocorticogram (Intracranial EEG)
CPT code 95829 denotes an electrocorticogram (ECoG), an intracranial recording of cortical electrical activity obtained by placing electrodes on the brain surface. ECoG is a critical diagnostic and intraoperative monitoring tool for patients with complex seizure disorders, focal cortical pathology, and for guiding resective neurosurgery. As an invasive neurophysiologic procedure, it has implications for surgical planning, perioperative resource use, and specialized facility requirements nationwide.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise briefing on clinical context, typical sites of service, and what to expect in claims and billing workflows for an intracranial cortical recording. The report outlines common benchmarking categories, relevant policy considerations affecting coverage and prior authorization, and operational factors such as site of care and associated surgical services.
This national overview is intended to inform coding and administrative teams about the clinical purpose of CPT code 95829, payer coverage landscape, and the types of documentation and setting information that commonly appear in claims. Data not available in the input are noted where applicable.
Billing Code Overview
CPT code 95829 describes an electrocorticogram (ECoG), also known as an intracranial electrocorticogram (iEEG). This procedure records electrical activity directly from the cerebral cortex by placing electrodes on the brain surface. The recording captures cortical electrical signals for diagnostic and monitoring purposes, often used when noninvasive EEG is insufficient.
Service type: Intracranial neurophysiologic monitoring / diagnostic cortical recording
Typical site of service: Inpatient or outpatient surgical setting within an operating room or specialized epilepsy monitoring unit where neurosurgical electrode placement is performed.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with medically refractory focal epilepsy admitted for intracranial monitoring to localize an epileptogenic focus prior to possible resective surgery. The patient has recurrent complex partial seizures not controlled with multiple antiseizure medications and noninvasive evaluation (MRI, scalp EEG, and PET) has been inconclusive or discordant. The neurosurgery and neurology teams perform a craniotomy and place subdural grid and/or strip electrodes on the cortical surface under general anesthesia. Intraoperative electrocorticography (95829) recordings are obtained to map epileptiform activity and to delineate cortical functional areas. The recording portion may occur intraoperatively or during an inpatient monitoring period in the neuroscience intensive care unit or an epilepsy monitoring unit. Postoperative care includes neurologic observation, management of intracranial pressure, wound care, and interpretation of ECoG data by the epileptologist and neurosurgeon to guide subsequent resection or electrode removal.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing the interpreting physician’s professional service separate from technical facility services |