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Official Description

Magnetoencephalography (MEG), recording and analysis; for evoked magnetic fields, each additional modality (eg, sensory, motor, language, or visual cortex localization) (List separately in addition to code for primary procedure)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Magnetoencephalography (MEG) is a sophisticated, noninvasive diagnostic technique utilized to assess and analyze abnormal brain function. This method is particularly valuable in the context of various neurological disorders and is often employed alongside other diagnostic studies, such as electroencephalograms (EEG) and magnetic resonance imaging (MRI). MEG is instrumental in localizing epileptic foci prior to surgical interventions and identifying eloquent cortical areas in the brain before surgeries aimed at addressing brain tumors, arteriovenous malformations, or epilepsy. The procedure utilizes a multichannel superconducting quantum interference device (SQUID) biomagnetometer system, which is equipped with over 100 sensors strategically placed on the scalp. These sensors are designed to detect and measure the magnetic fields produced by neuronal activity within the brain. The data collected from these magnetic field recordings are then meticulously mapped to pinpoint the locations of epileptic foci or eloquent cortical regions. Furthermore, the MEG mapping results are integrated with separately reportable MRI studies, allowing for precise localization of the identified brain areas. Following the procedure, a physician reviews the MEG recordings and mapping results, subsequently providing a comprehensive written interpretation of the findings. For accurate coding, it is essential to use CPT® code 95965 for MEG recording and analysis related to spontaneous brain magnetic activity, such as the localization of the epileptic cerebral cortex. Additionally, CPT® code 95966 is designated for single modality evoked magnetic fields aimed at localizing eloquent cortical areas of the brain. CPT® code 95967 is specifically utilized in conjunction with 95966 to account for each additional modality for evoked magnetic fields, which may include sensory, motor, language, or visual cortex localization.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The indications for performing magnetoencephalography (MEG) include the following:

  • Localization of Epileptic Foci MEG is utilized to accurately identify the locations of epileptic foci in patients with epilepsy, which is crucial for planning surgical interventions.
  • Localization of Eloquent Cortical Areas The procedure is employed to localize eloquent cortical areas of the brain, which are critical for functions such as sensory processing, motor control, language, and visual perception, prior to surgical procedures for brain tumors or arteriovenous malformations.

2. Procedure

The procedure for magnetoencephalography (MEG) involves several key steps that ensure accurate recording and analysis of brain activity:

  • Preparation of the Patient The patient is prepared for the MEG procedure by ensuring that they are comfortable and positioned appropriately. The scalp is typically cleaned to enhance the quality of the recordings, and the patient may be instructed to remain still during the procedure to minimize artifacts in the data.
  • Placement of Sensors A multichannel superconducting quantum interference device (SQUID) biomagnetometer system is utilized, which consists of over 100 sensors that are carefully positioned on the patient's scalp. These sensors are designed to detect the magnetic fields generated by neuronal activity in the brain.
  • Recording of Magnetic Fields The MEG system records the magnetic fields associated with brain activity as the patient engages in specific tasks or stimuli designed to evoke responses from different cortical areas. This may include sensory, motor, language, or visual tasks, depending on the clinical indications.
  • Mapping of Data The recorded magnetic field data is then processed and mapped to identify the locations of the brain activity. This mapping is crucial for localizing epileptic foci or eloquent cortical regions.
  • Integration with MRI The MEG mapping results are overlaid on separately reportable MRI studies of the brain. This integration allows for precise localization of the identified brain areas, enhancing the accuracy of surgical planning.
  • Interpretation of Findings After the completion of the MEG procedure, a physician reviews the recordings and the mapping results. The physician then provides a detailed written interpretation of the findings, which is essential for guiding further clinical decisions.

3. Post-Procedure

Post-procedure care for patients undergoing magnetoencephalography (MEG) typically involves monitoring the patient for any immediate effects following the procedure. Since MEG is a noninvasive technique, patients generally do not require extensive recovery time and can resume normal activities shortly after the procedure. However, it is important for the physician to discuss the findings with the patient and outline any necessary follow-up actions or additional diagnostic studies that may be required based on the MEG results. The written interpretation provided by the physician will guide further management and treatment options for the patient.

Short Descr MEG EVOKED EACH ADDL
Medium Descr MAGNETOENCEPHALOGRAPY EVOKED FIELDS EACH ADDL
Long Descr Magnetoencephalography (MEG), recording and analysis; for evoked magnetic fields, each additional modality (eg, sensory, motor, language, or visual cortex localization) (List separately in addition to code for primary procedure)
Status Code Carriers Price the Code
Global Days ZZZ - Code Related to Another Service
PC/TC Indicator (26, TC) 1 - Diagnostic Tests for Radiology Services
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Items and Services Packaged into APC Rates
Type of Service (TOS) 4 - Diagnostic Radiology
Berenson-Eggers TOS (BETOS) T2D - Other tests - other
MUE 3
CCS Clinical Classification 7 - Other diagnostic nervous system procedures

This is an add-on code that must be used in conjunction with one of these primary codes.

95966 MPFS Status: Carrier Priced APC S Magnetoencephalography (MEG), recording and analysis; for evoked magnetic fields, single modality (eg, sensory, motor, language, or visual cortex localization)
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
Notes
2021-01-01 Note Guidelines changed.
2011-01-01 Changed Medium description changed. Short description changed.
2002-01-01 Added First appearance in code book in 2002.
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