Neurology Billing Guide 2026: EEG, EMG, Cognitive Testing, and Infusion Coding

Published May 19, 2026 · 11 min read · By RCMAXIS Revenue Cycle Team

Neurology is one of the most procedure-rich cognitive specialties in medicine — a discipline where a single patient visit can involve an office E/M, an interpreted EEG, cognitive testing, and a discussion of infusion therapy, each with its own billing rules. Getting all of it right requires coders who understand not just the CPT codes, but the clinical context that determines when services are separately reportable and when they are bundled. The MGMA 2025 Report places neurology at a 13.5% average denial rate, with EMG bundling errors and documentation shortfalls driving the majority of preventable losses.

At RCMAXIS, our neurology billing specialists manage claims for academic neurology departments, private neurology groups, and subspecialty practices in epilepsy, movement disorders, and neuromuscular disease. Here is what you need to know.

1. EEG Coding: Routine, Extended, and Ambulatory

EEG code selection depends on recording duration, whether the patient is awake or asleep, and the recording method. The most common error is billing a routine awake EEG (95816) when the study extended into sleep, which changes the correct code to 95819.

EEG Code Reference

• 95812: EEG extended monitoring, 41–60 minutes — use when awake and drowsy study extends past the standard 20–40 minute window
• 95813: EEG extended monitoring, greater than 1 hour — continuous recordings beyond 60 minutes
• 95816: EEG, awake and drowsy — the standard outpatient EEG, patient does not achieve sleep
• 95819: EEG, awake and asleep — patient transitions into sleep during the recording; more clinically complete and higher-paying
• 95822: EEG, sleep only — recording during sleep without wakefulness captured
• 95827: EEG, all-night recording — used for nocturnal seizure evaluation, not polysomnography

Ambulatory EEG monitoring uses separate codes: 95950 for the hook-up and initial interpretation, 95951 for physician review of the recording. These are distinct from routine EEG codes and must not be cross-billed.

2. EMG and Nerve Conduction Studies: Bundling Rules

Electromyography (EMG) and nerve conduction studies (NCS) are separately reportable services but are subject to strict bundling rules and NCCI edits that trip up even experienced neurology coders. The key issue: needle EMG codes (95885–95887) are structured by extremity, while nerve conduction codes (95907–95913) are structured by the number of studies performed.

Nerve Conduction Study Code Reference

• 95907: 1–2 nerve conduction studies
• 95908: 3–4 studies
• 95909: 5–6 studies
• 95910: 7–8 studies
• 95911: 9–10 studies
• 95912: 11–12 studies
• 95913: 13 or more studies

Each motor or sensory conduction study on a distinct nerve counts as one study. F-wave and H-reflex studies count separately. Bill the single code representing the total number of conduction studies performed — do not bill multiple lower-range codes to represent a larger study.

Needle EMG Code Reference

• 95885: Needle EMG, each extremity with related paraspinal areas when reported — limited study (one to four muscles)
• 95886: Complete study, each extremity (five or more muscles)
• 95887: Needle EMG study of non-extremity muscles (cranial nerve, trunk) — add-on to 95885/95886

3. Cognitive Evaluation and Neuropsychological Testing

Cognitive testing is a high-value service in neurology, particularly for dementia evaluation, and is frequently undercoded. The 2023 CPT revisions restructured cognitive assessment codes, replacing older codes with a time-based pair that more accurately reflects the work involved.

Cognitive Assessment Code Reference

• 96116: Neurobehavioral status exam, clinical assessment of thinking, reasoning, and judgment — physician or QHP, first hour. Requires direct one-on-one patient time, face-to-face
• 96121: Each additional hour of neurobehavioral status exam (add-on to 96116)
• 96132: Neuropsychological testing evaluation, first hour (performed by physician or QHP)
• 96133: Each additional hour of neuropsychological testing evaluation

96116 is the appropriate code for a physician-performed cognitive evaluation during an office visit for dementia, MCI, or encephalopathy work-up. It cannot be billed on the same day as an E/M unless a separate, distinct problem was addressed in the E/M — document clearly with modifier 25 on the E/M.

4. Botulinum Toxin Injections: Billing Drug and Procedure

Botulinum toxin (Botox/onabotulinumtoxinA, Dysport/abobotulinumtoxinA, Xeomin/incobotulinumtoxinA) injections are used in neurology for chronic migraine, cervical dystonia, spasticity, hyperhidrosis, and blepharospasm. Both the procedure and the drug must be billed separately.

Injection Procedure Codes

• 64615: Chemodenervation of muscle(s); muscle(s) innervated by facial, trigeminal, cervical spinal, and accessory nerves — used for cervical dystonia and hemifacial spasm
• 64616: Chemodenervation, neck muscle(s), excluding muscles of the larynx — cervical dystonia (additional sites)
• 64642: Chemodenervation of one extremity, 1–4 muscles — spasticity
• 64644: Each additional extremity, 1–4 muscles (add-on)
• 64650: Chemodenervation, eccrine glands — hyperhidrosis (palms or axillae)
• 64999: Unlisted nerve procedure — used for certain migraine injection protocols when specific codes are not available

Drug HCPCS Codes

• J0585: OnabotulinumtoxinA (Botox) — per unit; document total units injected
• J0586: AbobotulinumtoxinA (Dysport) — per unit
• J0587: RimabotulinumtoxinB (Myobloc) — per 100 units
• J0588: IncobotulinumtoxinA (Xeomin) — per unit

Prior authorization is required by virtually every commercial payer for botulinum toxin — and by Medicare for chronic migraine indication. The auth must specify the diagnosis, the muscles to be injected, the dose, and the treating physician. A 22% denial rate on initial botulinum toxin claims is driven almost entirely by missing or insufficient prior auth documentation.

5. Infusion Therapy Billing in Neurology

Neurology practices administering IV infusions — natalizumab (Tysabri), ocrelizumab (Ocrevus), eculizumab (Soliris), IVIG — must bill both the drug administration service and the pharmaceutical separately. Administration time is the basis for billing, not the drug infusion time stated on the package insert.

Infusion Administration Code Reference

• 96365: IV infusion, therapeutic/prophylactic, first hour — the initial infusion code
• 96366: Each additional hour (add-on) — bill for each additional full hour beyond the first
• 96367: Additional sequential infusion of a new drug, up to 1 hour
• 96368: Concurrent infusion (simultaneous with another drug)

Document the start and stop time for every infusion in the nursing or clinical notes. Payers audit infusion claims for time documentation — missing timestamps are the primary reason infusion administration claims are denied or downcoded.

6. Sleep Medicine Coding in Neurology Practices

Many neurologists supervise sleep studies and interpret polysomnography reports. The key distinction for billing is whether the study was attended (technologist present throughout the night) or unattended (home sleep apnea test), and whether the physician performed the interpretation or only reviewed results generated by another provider.

Sleep Study Code Reference

• 95800: Sleep study, unattended, with oximetry, heart rate, and respiratory airflow — basic home sleep apnea test (HSAT)
• 95806: Sleep study, unattended, simultaneous recording of heart rate, oximetry, respiratory airflow and respiratory effort — Type III HSAT
• 95810: Polysomnography, attended, 6 or more hours, with 4+ additional parameters — standard PSG
• 95811: PSG with CPAP titration — split-night or full-night CPAP titration study

RCMAXIS's neurology billing team holds CNIM-adjacent coding expertise and works closely with physician practices to build pre-submission workflows that catch EMG bundling errors, missing botulinum auth documentation, and cognitive testing same-day conflicts before claims go out. Explore how our claims management process keeps neurology denial rates below 3%.