What Does CPT Code 00164 Mean?CPT code 00164 describes anesthesia services provided for biopsy of the nose. This is the lowest-complexity anesthesia code in the nasal procedure range, covering only diagnostic nasal biopsies performed under general anesthesia or monitored anesthesia care (MAC). It does not cover therapeutic nasal procedures (septoplasty, rhinoplasty, fracture reduction) — those are coded with 00160 or 00162.Key Code Attributes:- Billable Status: Fully billable as a standalone anesthesia service- Base Units (CMS 2026): 3- Primary Setting: Ambulatory surgery center or hospital outpatient- Provider Type: Anesthesiologist (MD/DO), CRNA with physician supervision- Service Category: MAC or general anesthesia- Effective Status: Active CPT code with no planned retirement (verified through 2026)- Common Procedures: Nasal biopsy (excisional or incisional) of suspicious lesion---## What Services and Procedures Does CPT Code 00164 Cover?CPT 00164 covers anesthesia for diagnostic biopsy procedures on the nasal cavity and nasal mucosa. These are typically brief procedures performed to obtain tissue for histopathologic diagnosis of suspicious lesions.Covered Procedures:- Nasal biopsy — excisional (full removal of small lesion for diagnosis)- Nasal biopsy — incisional (partial sampling of larger lesion)- Punch biopsy of nasal mucosa- Nasal lesion sampling under anesthesia (when patient cannot tolerate under local)### Exclusions| Excluded | Correct Code | Rationale ||----------|-------------|-----------|| Septoplasty or rhinoplasty | 00160 | Therapeutic nasal surgery || Rhinectomy or total reconstruction | 00162 | Radical nasal procedure || FESS or sinus procedure | 00103 | Sinus involvement || Office-based nasal biopsy | Not billable | No anesthesia provider || Integumentary skin biopsy on nose | 00100 | Skin-only procedure |---## When Is CPT Code 00164 the Right Code to Use?### Step-by-Step Code Selection1. Confirm the procedure is diagnostic nasal biopsy only — not therapeutic2. Verify that an anesthesia provider is actually required (patient unable to tolerate under local anesthesia)3. If the procedure is therapeutic (septoplasty, rhinoplasty, turbinate reduction), use 001604. If the procedure is radical (rhinectomy), use 001625. If the biopsy is on the external nasal skin only (not nasal mucosa), use 001006. Select appropriate modifiers for provider type and ASA physical status### Comparison With Related Codes| Code | Anatomic Area | Base Units (2026) ||------|---------------|-------------------|| 00164 | Nose — biopsy | 3 || 00160 | Nose — limited | 3 || 00162 | Nose — radical | 4 || 00103 | Nose and sinuses | 4 || 00100 | Integumentary — head and neck | 3 |---## Documentation Requirements### Preoperative DocumentationHistory and physical with airway assessment, ASA classification, anesthesia plan (MAC vs. general anesthesia), NPO status, anticoagulant review, and documentation of why the biopsy requires an anesthesia provider (patient anxiety, lesion location, inability to tolerate under local).### Intraoperative DocumentationAnesthesia start and stop times, vital signs recorded at minimum 5-minute intervals, all anesthetic agents and doses, level of sedation monitoring (for MAC), oxygen administration method, and any specimens or biopsy results communicated.### Postoperative DocumentationPACU admission and discharge times, pain scores, PONV assessment, Aldrete score, and any specific post-biopsy instructions (bleeding monitoring, nasal packing documentation).### Base Unit Assignment| Component | Value ||-----------|-------|| Base Units (CMS 2026) | 3 || Time Unit Increment | 15 minutes || Physical Status P3 | +1 unit || Physical Status P4 | +2 units || Physical Status P5 | +3 units |---## ReimbursementNote: Anesthesia services use a unit-based formula, not RVUs. Medicare payment = (Base Units + Time Units + Modifying Units) x Anesthesia Conversion Factor. The 2026 Medicare anesthesia CF is approximately $21.71 (varies by locality). Commercial payer CFs are typically 2-5x higher.### Common Modifiers| Modifier | Use Case ||----------|----------|| AA | Anesthesiologist personally performs service || QS | Monitored anesthesia care (MAC) || QK | Medical direction of 2-4 concurrent cases || QX | CRNA with medical direction || QZ | CRNA without medical direction || P1-P4 | ASA physical status |### Payer Considerations- Medicare covers CPT 00164 when the nasal biopsy is medically necessary and the patient requires anesthesia provider involvement- Brief biopsies under local anesthesia alone in an office setting are not eligible for anesthesia billing- Commercial payers may question medical necessity for anesthesia on brief nasal biopsies — document why the patient could not tolerate the procedure under local anesthesia alone- Prior authorization is typically not required for diagnostic nasal biopsy- For biopsies performed in conjunction with another therapeutic nasal procedure, use the therapeutic code (00160 or 00162) instead of 00164- Verify with the specific payer whether a separate anesthesia code is payable when the surgeon performs the biopsy in an ASC setting---## Coding Errors to Avoid1. Using 00164 for therapeutic procedures — Septoplasty, rhinoplasty, and turbinate reduction require 001602. Using 00164 for sinus biopsy — Biopsy of the sinuses requires 001033. Billing 00164 for office-based biopsy — No anesthesia code is reported when no anesthesia provider is involved4. Using 00164 for skin biopsy on the nose — Skin-only biopsies on the external nose use 001005. Billing 00164 with 00160 in the same session — When a biopsy is performed during a therapeutic nasal procedure, report only the therapeutic code6. Failure to document anesthesia medical necessity — Brief procedures attract scrutiny; document why sedation or general anesthesia was required---## Real-World Scenario### Scenario 1: Excisional Nasal Biopsy Under MACA 65-year-old male with a suspicious nasal lesion on the nasal septum undergoes excisional nasal biopsy under MAC with local infiltration. The patient has significant anxiety and cannot tolerate the procedure under local alone. Total anesthesia time is 30 minutes. Patient is ASA II.Coding: CPT 00164 + AA + P2 + QS. Base 3, time 2 (30 min), total 5 units. Estimated payment at $21.71/unit: ~$108.55.### Scenario 2: Nasal Biopsy for GranulomatosisA 45-year-old female with suspected granulomatosis with polyangiitis undergoes incisional nasal mucosal biopsy under general anesthesia via laryngeal mask airway. The lesion is located deep in the nasal cavity and requires patient immobility. Total anesthesia time is 20 minutes. Patient is ASA II.Coding: CPT 00164 + AA + P2. Base 3, time 1 (20 min rounds to 1), total 4 units. Estimated payment: ~$86.84.---## Frequently Asked Questions### What Is the Difference Between CPT 00164 and CPT 00160?CPT 00164 is specifically for diagnostic nasal biopsy only. CPT 00160 is for therapeutic nasal procedures (septoplasty, rhinoplasty, turbinate reduction, fracture reduction). Both have 3 base units, but 00164 is intended for shorter, purely diagnostic cases.### Is MAC or General Anesthesia More Common for CPT 00164?MAC is more common for nasal biopsy because these are typically brief, minimally invasive procedures. General anesthesia may be used for patients who cannot tolerate sedation or when the lesion location requires complete immobility.### Can CPT 00164 Be Billed for Office-Based Nasal Biopsy?No. Office-based nasal biopsy performed by the surgeon under topical or local anesthesia without an anesthesia provider does not qualify for a separate anesthesia code. CPT 00164 requires an anesthesia provider to be present and managing the patient’s sedation or anesthesia.### Does CPT 00164 Cover Biopsy of the Sinuses?No. Biopsy of the paranasal sinuses requires CPT 00103 (nose and sinuses), not 00164.### What Documentation Supports Medical Necessity for CPT 00164?Documentation should explain why the patient requires an anesthesia provider for the biopsy — reasons may include patient anxiety, inability to tolerate the procedure under local anesthesia, lesion location requiring patient immobility, or medical comorbidities that require monitored sedation.### Can CPT 00164 Be Billed With Other Anesthesia Codes?No. Only one anesthesia code is reported per anesthetic session. If a nasal biopsy is performed during a therapeutic nasal procedure, report only the therapeutic code (00160 or 00162) — the biopsy is considered part of the overall surgical service.### What Is the Typical Reimbursement Range for CPT 00164?At 5 total units with the 2026 Medicare CF of $21.71, reimbursement is approximately $108.55. Commercial payers at $50-80/unit would yield $250-400 for the same service.### Can CPT 00164 Be Used for Nasal Polyp Removal?No. Nasal polypectomy is a therapeutic procedure and should be coded with 00160 (limited nose) or 00103 (if sinuses are involved). CPT 00164 covers diagnostic biopsy only.---## Key Takeaways- CPT 00164 is specifically for diagnostic nasal biopsy only- Base units 3 — same base as limited nose (00160) but intended for shorter diagnostic cases- Do not use for therapeutic procedures (use 00160 or 00162)- MAC with local sedation is common for brief nasal biopsies- Single code per anesthetic session- Document medical necessity for anesthesia provider involvement- Sinus biopsies require 00103, not 00164## References- CMS PFS: cms.gov- ASA Relative Value Guide