What Does CPT Code 00104 Mean?

CPT code 00104 describes anesthesia services provided for electroconvulsive therapy (ECT), also known as electroshock therapy. This is a specialized psychiatric treatment in which controlled seizures are electrically induced in the brain to alleviate severe mental health conditions. ECT is performed under brief general anesthesia with a muscle relaxant to prevent physical injury during the seizure.

ECT is primarily used to treat major depressive disorder, bipolar disorder, and certain types of schizophrenia when other treatments have been ineffective or when rapid symptom relief is needed. The anesthesia component is critical — the patient must be rendered unconscious and paralyzed before the electrical stimulus is delivered, and the seizure activity must be carefully monitored.

Key Code Attributes:

• Billable Status: Fully billable as a standalone anesthesia service
• Base Units (CMS 2026): 4
• Primary Setting: Hospital ECT suite, psychiatric unit, operating room, or dedicated ECT treatment center
• Provider Type: Anesthesiologist (MD/DO) or CRNA under physician supervision
• Service Category: Brief general anesthesia (typically 5-15 minutes per session)
• Effective Status: Active CPT code with no planned retirement (verified through 2026)
• Typical Patient Population: Adults with treatment-resistant depression, bipolar disorder, catatonia, or acute suicidal ideation

What Services and Procedures Does CPT Code 00104 Cover?

CPT 00104 covers anesthesia for electroconvulsive therapy sessions. Each ECT session requires brief general anesthesia, typically lasting 5-15 minutes from induction to emergence.

Covered Procedures and ECT Indications:

• Electroconvulsive therapy for major depressive disorder (severe, treatment-resistant, or with psychotic features)
• Bipolar disorder (severe manic or depressive episodes)
• Schizophrenia and schizoaffective disorder (particularly with catatonia)
• Catatonia (malignant or neuroleptic-induced)
• Acute suicidal ideation requiring rapid intervention
• Treatment-resistant psychiatric conditions unresponsive to medication
• Maintenance ECT for relapse prevention in chronic, recurring illness
• ECT during pregnancy when medication is contraindicated

Anesthesia Protocol for ECT

ECT anesthesia follows a specific protocol:

1. Pre-oxygenation with 100% oxygen
2. Induction with a short-acting anesthetic agent (methohexital 0.5-1 mg/kg or propofol 0.5-1 mg/kg)
3. Muscle relaxation with succinylcholine 0.5-1 mg/kg or a non-depolarizing agent
4. Hyperventilation to lower seizure threshold
5. Bite block placement to protect teeth and tongue
6. Electrical stimulus delivery by the psychiatrist
7. Monitoring of seizure activity (EEG and motor response)
8. Emergence and recovery monitoring

What Does CPT 00104 Specifically Exclude?

CPT 00104 does not cover anesthesia for:

• Transcranial magnetic stimulation (TMS) — no anesthesia code required
• Vagal nerve stimulation (VNS) placement — uses appropriate surgical anesthesia code
• Deep brain stimulation (DBS) procedures — uses appropriate intracranial anesthesia code
• General anesthesia for other psychiatric procedures (use appropriate code based on procedure)
• Moderate sedation for ECT (ECT always requires general anesthesia)
• The ECT procedure itself (psychiatrist bills surgical code 90870)
• Magnetic seizure therapy (MST) — check payer policy for appropriate coding

When Is CPT Code 00104 the Right Code to Use?

Use CPT 00104 when anesthesia is provided specifically for electroconvulsive therapy.

Step-by-Step Code Selection:

1. Confirm the procedure is ECT — verify informed consent is for electroconvulsive therapy
2. Verify an anesthesia provider is involved — ECT always requires an anesthesia provider
3. Confirm the surgical code 90870 (ECT) is also being billed by the psychiatrist
4. Check for the number of ECT treatments — each treatment session is a separate encounter
5. Verify the patient’s NPO status and pre-anesthesia evaluation is complete
6. Document the specific anesthetic agents used and their doses

How Does CPT 00104 Differ From Related Codes?

| Code | Description | Base Units | |---

---|-------------|------------| | 00104 | Anesthesia for ECT | 4 | | 90870 | ECT procedure (psychiatrist’s code, not anesthesia) | N/A | | 99155-99157 | Moderate sedation by separate provider | N/A | | 00100 | Integumentary/salivary gland procedures | 5 |

What Documentation Is Required to Support CPT 00104?

What Must the Provider Document?

Preoperative Documentation:

• Complete medical history and physical examination
• Psychiatric diagnosis and indication for ECT
• ASA Physical Status Classification
• Airway assessment
• Fasting status
• History of prior response to anesthetic agents
• Review of current psychiatric medications and interactions
• Informed consent for anesthesia
• Baseline cognitive status Intraoperative Documentation:
• Anesthesia start and stop times
• Induction agent and dose
• Muscle relaxant and dose
• Seizure duration (EEG and motor)
• Vital signs before, during, and after stimulus
• Oxygen saturation throughout
• Any complications or adverse events
• Bite block placement confirmation Postoperative Documentation:
• PACU admission and discharge times
• Pain scores and treatment (headache is common post-ECT)
• Nausea/vomiting assessment
• Recovery of baseline mental status
• Aldrete score or equivalent
• Discharge criteria met

Frequently Asked Questions About CPT Code 00104

How many base units does CPT 00104 have?

CPT 00104 has 4 base units under the 2026 CMS Physician Fee Schedule. This reflects the relatively brief but specialized nature of ECT anesthesia.

Is CPT 00104 billed per ECT treatment session?

Yes. Each ECT session is a separate anesthesia encounter billed with CPT 00104. A typical course includes 6-12 treatments over 2-4 weeks. Maintenance ECT may continue monthly or less frequently.

Can propofol be used for ECT anesthesia?

Yes. While methohexital is the traditional induction agent for ECT (it has less anticonvulsant effect and allows longer seizure duration), propofol is also commonly used. Seizure duration may be shorter with propofol, but this is clinically acceptable.

Does CPT 00104 require time units?

Time units are calculated the same way as other anesthesia codes. However, ECT sessions are very brief (typically 5-15 minutes), so time units contribute minimally to total reimbursement. The base units (4 per treatment) drive the majority of payment.

Key Takeaways for Billing and Coding CPT 00104

• CPT 00104 is specific to anesthesia for electroconvulsive therapy — not for other psychiatric procedures
• Base units are 4 under the 2026 CMS Physician Fee Schedule
• ECT is typically performed as a series of treatments; each is a separate claim
• Brief general anesthesia with short-acting agents is the standard
• Common audit targets include documenting seizure duration, appropriate agent selection, and anesthesia start/stop times

Additional Resources and References

• CMS Physician Fee Schedule: Official source for base units, conversion factors, and reimbursement data
• APA Task Force on ECT: Clinical practice guidelines for electroconvulsive therapy
• ASA Relative Value Guide: The American Society of Anesthesiologists annual RVG
• AMA CPT Professional Edition: The official CPT code set