CPT Code 00160: Anesthesia for Nose and Accessory Sinus Procedures – Complete Billing & Coding Guide

What Does CPT Code 00160 Mean?

CPT code 00160 is defined by the AMA as “Anesthesia for procedures on the nose and accessory sinuses; not otherwise specified.” It is reported by anesthesiologists or certified registered nurse anesthetists (CRNAs) who provide anesthesia care — including pre-induction assessment, intraoperative monitoring, and transfer to post-anesthesia care — during surgical procedures involving the nasal cavity, nasal septum, turbinates, or paranasal sinuses when no more specific anesthesia code applies.

Key attributes of this code at a glance:

• Billable provider types: Anesthesiologists, CRNAs, anesthesiologist assistants (AAs)
• Applicable settings: Hospital inpatient, hospital outpatient, ambulatory surgical center (ASC)
• Service category: Surgical anesthesia (not monitored anesthesia care by default)
• ASA base unit value: 5 base units (per the ASA Relative Value Guide)
• Code status as of 2026: Valid and billable; descriptor revised effective January 1, 2026 — verify short description with your encoder against the current AMA CPT code set

What Procedures Does CPT 00160 Cover?

CPT 00160 is a “not otherwise specified” (NOS) catch-all anesthesia code for the nasal and sinus region. Use it when the surgical CPT code for the operative procedure maps to the nose or accessory sinuses and no more specific anesthesia code in the 00160–00164 family applies.

Common surgical procedures whose anesthesia crosswalks to CPT 00160 include:

• Septoplasty (CPT 30520) — the single most frequently reported procedure under this code
• Functional endoscopic sinus surgery (FESS), including ethmoidectomy, maxillary antrostomy, and sphenoidotomy (CPT 31254, 31255, 31267, 31276)
• Septorhinoplasty (CPT 30450) when performed without radical resection
• Turbinate reduction procedures (CPT 30130, 30140)
• Nasal polypectomy (CPT 30110, 30115)
• Rhinoplasty (CPT 30400–30420) for functional indications
• Repair of nasal fracture or reduction of nasal bones (CPT 21310–21315) when anesthesia is required

What Does CPT 00160 Specifically Exclude?

Use a more specific code whenever one exists in the sibling code family:

• CPT 00162 — Use instead when the procedure is classified as radical surgery of the nose or accessory sinuses (e.g., total rhinectomy, radical maxillectomy, or craniofacial resection involving the sinuses)
• CPT 00164 — Use instead when the procedure is a soft tissue biopsy of the nose only
• CPT 00190 — Use instead when the operative site involves the facial bones or skull (not the nose/sinuses specifically)

In practice, the most frequent misapplication seen during anesthesia coding audits is defaulting to 00160 for radical sinus resections that clearly meet the threshold for 00162 — a difference of 8 vs. 5 base units under the ASA Relative Value Guide, which materially affects reimbursement.

When Is CPT 00160 the Right Code to Use?

Selecting CPT 00160 correctly requires a two-step verification process before appending modifiers or calculating time units:

1. Confirm the operative site is the nose, nasal septum, nasal turbinates, or one or more accessory sinuses (maxillary, ethmoid, frontal, or sphenoid).
2. Confirm the procedure does not qualify as radical surgery (→ 00162) and is not limited to a soft tissue biopsy alone (→ 00164).
3. Identify the surgical CPT code(s) from the operative report and cross-reference against the ASA Crosswalk (ASA Relative Value Guide) to confirm 00160 is the assigned anesthesia code.
4. Verify no more specific anesthesia code exists by reviewing the full 00160–00164 family in the current AMA CPT code set.
5. Confirm the procedure was performed in a setting where anesthesia is separately billable (not bundled into a global payment under the OPPS for hospital outpatient services).

How Does CPT 00160 Differ From CPT 00162 and CPT 00164?

The base unit differential between 00160 and 00162 is meaningful: at the 2025 national Medicare anesthesia conversion factor of $20.3178 (per the American Society of Anesthesiologists), 3 additional base units translate to approximately $61 in added reimbursement before time units — understating the impact of downcoding radical procedures.

What Documentation Is Required to Support CPT 00160?

Anesthesia claims are paid on a base-unit-plus-time-unit formula, which means documentation must substantiate both the code selection and the exact duration of the anesthesia service. A missing stop time or an unsigned preanesthesia evaluation is not a minor clerical issue — it is grounds for claim denial or post-payment recovery.

What Must the Anesthesia Provider Document in the Anesthesia Record?

The following elements are required to support a valid CPT 00160 claim:

1. Preanesthesia evaluation — completed and signed before induction, documenting patient history, ASA physical status classification, and anesthesia plan
2. Intraoperative anesthesia record — including all agents administered (name, dose, route, time), mode of anesthesia (general, regional, or MAC/sedation), and physiologic monitoring data (heart rate, blood pressure, SpO2, capnography intervals)
3. Anesthesia start time — documented as the time the anesthesia provider began preparing the patient for induction (not the surgical incision time)
4. Anesthesia stop time — documented as the time the anesthesia provider transferred care to post-anesthesia care unit (PACU) personnel
5. Physical status modifier — ASA P1 through P6, documented in the preanesthesia evaluation and reflected in the claim modifier
6. Diagnosis support — a primary ICD-10-CM diagnosis code linked to the anesthesia claim that establishes medical necessity documentation for the surgical procedure requiring anesthesia
7. Provider identification — clear notation of whether the anesthesiologist personally performed the service, directed a CRNA, or co-managed with a resident, which drives modifier selection

What Documentation Standards Apply in Facility vs. Non-Facility Settings?

How Does CPT 00160 Affect Medical Billing and Reimbursement?

Unlike standard surgical or E&M codes, anesthesia billing does not use the traditional work RVU + practice expense RVU formula. Reimbursement for CPT 00160 is calculated as:

(Base Units + Time Units + Physical Status Units + Qualifying Circumstance Units) × Conversion Factor = Reimbursement

Applying this formula to CPT 00160:

Important: The above is a simplified illustrative calculation using national figures. Actual reimbursement is adjusted by the geographic practice cost index (GPCI) for your Medicare Administrative Contractor locality. Always verify current conversion factors via the CMS Physician Fee Schedule lookup tool at cms.gov.

What Modifiers Are Commonly Used With CPT 00160?

Modifier sequencing is the single most common billing error in anesthesia claims. Payers require a pricing modifier in the first position and a service indicator modifier in the second position when applicable.

Are There Any Prior Authorization, Coverage Restrictions, or LCD Requirements?

• Medicare MAC coverage: Anesthesia services are generally covered under Medicare Part B when furnished incident to a covered surgical procedure. CPT 00160 has no standalone NCD (National Coverage Determination) restricting its use.
• MAC (Monitored Anesthesia Care) billing: When reporting CPT 00160 with modifier QS, the linked ICD-10-CM diagnosis must appear on the applicable Local Coverage Determination (LCD) published by the provider’s MAC (e.g., Noridian, Novitas, CGS). If the diagnosis does not appear on the LCD list, the claim will deny regardless of modifier accuracy.
• NCCI bundling: CPT 00160 itself is not subject to NCCI procedure-to-procedure (PTP) edit pairings with the surgical procedure codes it supports, because anesthesia is always billed as a separate service by a separate provider. However, providers should verify that qualifying circumstance add-on codes (99100, 99116, 99135, 99140) are appended correctly and are not bundled by individual payer edit.
• Commercial payer variation: UnitedHealthcare requires QX or QZ for all CRNA-billed claims. Anthem/Blue plans emphasize correct MAC billing with G8 or G9 in the second position. Always verify payer-specific modifier billing rules before submitting.

What CPT or HCPCS Codes Are Commonly Billed Alongside CPT 00160?

Because CPT 00160 represents the anesthesia service only, it will always appear on a separate claim line from the surgeon’s procedure code. The following codes appear frequently on the same date-of-service remittance or in the same operative episode:

Which Code Combinations Trigger NCCI or CCI Edits?

CPT 00160 itself is not directly implicated in CCI/NCCI procedure-to-procedure edits because anesthesia codes occupy a separate billing lane from surgical codes. However, watch for these risk areas:

• Billing two anesthesia codes for the same date of service (e.g., 00160 and 00162 billed by the same provider on the same case) will trigger a claim-level edit
• Qualifying circumstance add-on codes (99100 series) may be down-bundled by commercial payers that do not recognize them as separately reimbursable — always verify the payer’s NCCI bundling edits policy before appending
• When bilateral or multiple sinus procedures are performed in the same session, anesthesia time documentation must capture the total continuous service, not separate time segments per procedure

What Coding Errors Should You Avoid With CPT 00160?

The following errors are the most frequently cited during anesthesia coding audits and payer overpayment recovery reviews:

1. Applying 00160 when 00162 is correct — If the operative report documents a radical nasal or sinus resection, 00162 (8 base units) is required. Using 00160 (5 base units) undercodes the service and may trigger a correction request if discovered during a MAC post-payment audit.
2. Incorrect modifier sequencing — Placing QS, G8, or G9 in the first position rather than the second position is an immediate claim denial trigger for most payers. The pricing modifier always comes first.
3. Omitting or rounding anesthesia time incorrectly — Medicare requires time reported to the nearest tenth of a unit; commercial payers often require whole units rounded per contract. Conflating these rules leads to over- or under-billing.
4. Billing physical status modifiers (P1–P6) to Medicare — Medicare does not reimburse additional units for physical status. Billing P3 as a unit modifier to Medicare is non-compliant and will be stripped on adjudication.
5. MAC billing without an LCD-supported diagnosis — The linked ICD-10-CM code must appear on the MAC’s current LCD for the QS modifier to be accepted. This error is among the most overlooked MAC billing pitfalls in ENT-heavy practices.
6. Using 00160 for soft tissue biopsy of the nose only — When the sole procedure is a nasal biopsy, 00164 (3 base units) is the correct code. Reporting 00160 (5 base units) for a biopsy-only case is an overcoding risk.

What Do Auditors and RAC Reviewers Look for When Reviewing CPT 00160 Claims?

During coding audit preparation, anesthesia reviewers specifically flag the following patterns:

• Missing or incomplete preanesthesia evaluations (particularly in high-volume ASC settings)
• Anesthesia start/stop times that are missing, illogical, or inconsistent with the operative record
• Physical status modifier claims billed to Medicare with P1–P6 unit additions
• CRNA claims where the supervising anesthesiologist’s documentation of active medical direction is absent or insufficient (TEFRA requirements)
• MAC claims where the ICD-10 diagnosis does not appear on the MAC’s LCD list
• Qualifying circumstance add-on codes billed without corresponding documentation in the anesthesia record

Real-World Coding Scenario — How CPT 00160 Is Applied in Practice

Clinical encounter: A 58-year-old patient (ASA P2 — mild controlled hypertension) presents for septoplasty (CPT 30520) and bilateral inferior turbinate reduction (CPT 30140) under general anesthesia. The anesthesiologist personally performs the entire service. Anesthesia start time is documented as 7:42 AM; stop time is 9:18 AM (96 minutes = 6.4 time units under Medicare rounding).

Correct Code Application

• Anesthesia code: CPT 00160 (septoplasty crosswalks to 00160 per ASA RVG; turbinate reduction is concurrent in the same anesthesia episode — no separate code)
• Modifier: AA (personally performed)
• Physical status: P2 — no unit addition for Medicare; document in preanesthesia evaluation
• Diagnosis: J34.2 (deviated nasal septum) as primary; J34.3 (hypertrophy of nasal turbinates) as secondary
• Payment calculation (illustrative, national 2025 CF): (5 base + 6.4 time) × $20.3178 = approximately $233.66

Common Mistake in This Scenario

• Incorrect: Billing CPT 00160 with modifier P2 as a unit-adding modifier on the Medicare claim
• Why it fails: Medicare does not recognize physical status as a separately reimbursable unit component. The claim will adjudicate correctly, but the P2 modifier notation may cause downstream confusion on audit review if it appears in a unit field rather than the modifier field
• Also incorrect: Billing CPT 00160 and CPT 00140 on the same claim to account for the turbinate procedure — anesthesia is billed as a single continuous service; the anesthesiologist does not separately bill for each concurrent surgical procedure performed in one session

Frequently Asked Questions About CPT Code 00160

Is CPT Code 00160 Still Valid for Billing in 2026?

CPT code 00160 remains a valid and active anesthesia code in 2026, though the short and medium descriptor language was revised effective January 1, 2026. Coders should confirm the current descriptor text against the AMA CPT Professional Edition and verify base unit values against the most current ASA Relative Value Guide before processing claims.

What Is the Difference Between CPT 00160 and CPT 00162?

CPT 00160 covers anesthesia for routine nose and sinus procedures (“not otherwise specified”), while CPT 00162 is used specifically for radical nasal or sinus surgery. The distinction matters financially: 00162 carries 8 ASA base units compared to 00160’s 5, making it critical to match the anesthesia code to the surgical complexity documented in the operative report.

How Do You Calculate Anesthesia Time for CPT 00160?

Anesthesia time for CPT 00160 begins when the anesthesia provider starts preparing the patient for induction and ends when the provider transfers the patient to PACU personnel. Under Medicare, divide total minutes by 15 and report to the nearest tenth of a unit (e.g., 96 minutes ÷ 15 = 6.4 units). Many commercial payers require whole units rounded per contract terms — always verify your specific payer agreement.

Does Medicare Pay Physical Status Modifiers With CPT 00160?

Medicare does not reimburse additional units for physical status modifiers P1 through P6 under CPT 00160 or any anesthesia code. Physical status modifiers should still be documented and appended to the claim for informational purposes, but no additional unit value will be calculated by Medicare on adjudication. Many commercial payers do reimburse P3–P5 units — confirm each payer’s policy individually.

Which ICD-10-CM Codes Support CPT 00160 Claims?

Common ICD-10-CM diagnoses that establish medical necessity documentation for procedures billed with CPT 00160 include J34.2 (deviated nasal septum), J32.0 (chronic maxillary sinusitis), J32.9 (chronic sinusitis, unspecified), J33.0 (polyp of nasal cavity), J31.0 (chronic rhinitis), and J34.3 (hypertrophy of nasal turbinates). For MAC claims with modifier QS, the specific diagnosis must appear on the local MAC’s applicable LCD or the claim will deny regardless of other billing accuracy.

Can a CRNA Bill CPT 00160 Without an Anesthesiologist?

A CRNA may bill CPT 00160 independently when working without physician medical direction, using modifier QZ. When a CRNA works under anesthesiologist medical direction of 2–4 concurrent cases, the CRNA bills CPT 00160 with modifier QX, and the anesthesiologist bills CPT 00160 with modifier QK on a separate claim line. Each line reimburses at 50% of the physician-performed (AA) rate under Medicare’s split-billing rules.

What Happens if CPT 00160 Is Billed When CPT 00164 Should Have Been Used?

Billing CPT 00160 (5 base units) when the procedure is limited to a nasal soft tissue biopsy (correctly coded as CPT 00164 at 3 base units) constitutes overcoding — a compliance risk that can trigger payer recoupment if identified during a post-payment audit. If the operative report documents only a nasal biopsy, use 00164 and document accordingly, regardless of the anesthesia duration.

Key Takeaways for Billing and Coding CPT 00160

• CPT 00160 is the default anesthesia code for routine nose and accessory sinus procedures; always confirm that 00162 (radical surgery) or 00164 (biopsy only) is not the more accurate option before reporting 00160
• ASA base units for 00160 are 5; anesthesia time units are added at 1 unit per 15 minutes, with Medicare requiring reporting to the tenth of a unit
• Modifier sequencing is mandatory: pricing modifier (AA, QK, QX, QY, QZ, or AD) must always appear in the first position; service indicator modifiers (QS, G8, G9) go in the second position
• Medicare does not reimburse physical status units; document physical status in the preanesthesia evaluation for clinical and audit purposes, but do not add unit value to Medicare claims
• MAC billing with modifier QS requires a linked ICD-10-CM diagnosis that appears on the local MAC’s LCD — this is among the most frequently overlooked denial triggers for ENT-focused anesthesia practices
• A complete anesthesia record with signed preanesthesia evaluation, documented start/stop times, and agent/monitoring notations is the foundation of coding audit preparation and payer compliance for every CPT 00160 claim
• Verify base units, descriptor text, and the anesthesia conversion factor annually, as each may be revised; the 2025 national Medicare anesthesia CF is $20.3178 per the CMS Physician Fee Schedule

For complete anesthesia billing policy and current conversion factors, refer to the CMS Medicare Claims Processing Manual, Chapter 12, Section 50, and the current ASA Relative Value Guide published annually by the American Society of Anesthesiologists.