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Billing Codes

CPT Code 00174: Anesthesia for intraoral procedures

Avatar photo Alex Koch
Last Updated: September 10, 2026
Key Takeaways

Key Takeaways

CPT Code 00174 describes anesthesia for intraoral procedures, including biopsy; excision of retropharyngeal tumor, classified under the CPT head anesthesia section (00100-00222).

The code carries 6 base units; total reimbursement is calculated using: (base units + time units + modifying units) x conversion factor.

Common billing errors include omitting the QS modifier for MAC cases and misapplying CRNA supervision modifiers (QX, QY, QZ, QK) without confirming the medical direction ratio.

Pabau’s claims management software supports accurate CPT code submission with procedure code libraries and digital documentation workflows that reduce claim errors.

CPT Code 00174 is the anesthesia code for intraoral procedures, including biopsy or excision of a retropharyngeal tumor, billed within the CPT Head Anesthesia section (00100-00222). It carries 6 base units and is frequently confused with the adjacent not-otherwise-specified code, CPT 00170.

This reference guide covers the official descriptor for CPT Code 00174, its 6 base units, the anesthesia billing formula with a worked example, applicable modifiers, qualifying circumstances, ICD-10 crosswalk codes, and documentation requirements for clean claim submission.

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CPT Code 00174: Description and classification

CPT Code 00174 is the correct procedure code for anesthesia services provided during intraoral surgical procedures, including biopsy; excision of retropharyngeal tumor. It sits within the CPT Anesthesia section, under the subsection covering procedures on the head (codes 00100-00222), as maintained by the American Medical Association (AMA), the authoritative body for CPT code definitions.

FieldDetail
CPT Code00174
Short DescriptorAnesthesia for intraoral procedures, including biopsy; excision of retropharyngeal tumor
CPT SectionAnesthesia > Head (00100-00222)
Base Units6
Typical ProvidersAnesthesiologists, CRNAs (Certified Registered Nurse Anesthetists)
Code StatusActive (verify against current year CPT code book)

The code covers anesthesia services for intraoral surgical procedures where a retropharyngeal tumor excision is performed, as named specifically in the descriptor. Oral and maxillofacial procedures requiring intraoral access to excise a retropharyngeal tumor should use CPT Code 00174 rather than a more general intraoral biopsy code. See also other CPT coding references on the Pabau procedure codes resource library. Payment posting from a remittance file is faster than manual entry and keeps the adjustment reasons attached. Two practices can bill the same encounter at a different visit level, and the note settles which was right.

CPT 00174 anesthesia base units

CPT 00174 carries 6 base units. Base units represent the inherent complexity and risk of the anesthesia service itself, independent of how long the procedure takes. The American Society of Anesthesiologists (ASA) assigns base unit values; higher-risk or more technically demanding procedures carry more base units.

For context, common head anesthesia codes carry between 4 and 15 base units. At 6 units, CPT 00174 sits toward the lower end of that range. Time units are added on top, which is covered in the billing formula section below.

How to calculate reimbursement for CPT Code 00174

Anesthesia billing uses a unit-based formula, not the standard RVU system used for most other CPT codes. The CMS Physician Fee Schedule publishes the Medicare anesthesia conversion factor annually; commercial payers set their own conversion factors, which vary by contract.

ComponentDescriptionExample (CPT 00174)
Base UnitsInherent procedure complexity (assigned by ASA)6
Time Units1 unit per 15 minutes of anesthesia time (most payers; some use 10-min increments)4 (60-minute case = 4 units)
Modifying UnitsQualifying circumstances add-on codes (99100-99140)1 (e.g., patient under age 1 year, code 99100)
Conversion FactorDollar value per unit; varies by payer, year, and geography~$21 (approximate Medicare range; confirm current year rate)
Total UnitsBase + Time + Modifying6 + 4 + 1 = 11 units
Estimated PaymentTotal Units x Conversion Factor11 x ~$21 = ~$231 (illustrative only)

The formula is: (Base Units + Time Units + Modifying Units) x Conversion Factor = Reimbursement. The Medicare conversion factor changes annually and varies by geographic locality. Use the FastRVU 2026 RVU lookup to confirm current-year Medicare anesthesia conversion factor values by locality. Commercial payer rates are contract-specific and often higher than Medicare.

Time reporting: most payers follow the CMS standard of 1 time unit per 15 minutes. Some commercial payers use 10-minute increments. Verify your payer’s time unit convention before submitting claims for CPT Code 00174 to avoid systematic underpayment or audit flags.

The best medical practice management tools capture start and stop times at the point of care, which anesthesia billing depends on.

Modifiers for CPT Code 00174

Modifier selection is where most CPT 00174 claims run into trouble. Anesthesia modifiers signal who delivered the service and under what supervision arrangement. Selecting the wrong modifier triggers denials and can flag an account for audit. Use AAPC Codify to verify modifier applicability against current payer policies.

ModifierDescriptionWhen to Use
AAAnesthesia services personally performed by anesthesiologistAnesthesiologist is present and personally performs the entire service
QXCRNA service with medical direction by physicianCRNA performing under an anesthesiologist’s medical direction
QYMedical direction of one CRNA by an anesthesiologistAnesthesiologist directing exactly one CRNA
QZCRNA service without medical direction by physicianCRNA practicing independently (where state law permits)
ADMedical supervision by physician, more than 4 concurrent proceduresAnesthesiologist supervising 5+ concurrent CRNA cases
QKMedical direction of 2-4 concurrent anesthesia proceduresAnesthesiologist directing 2-4 simultaneous CRNA cases
QSMonitored Anesthesia Care (MAC)Required by Medicare for all MAC claims; verify other payer requirements
G9MAC for patient with history of severe cardiopulmonary conditionPatient has documented severe cardiopulmonary condition; confirm payer requirements

For anesthesia and procedure code modifiers, the supervision ratio matters. Medicare distinguishes between medical direction (QX/QY/QK, where the anesthesiologist directs 1-4 CRNAs and meets specific service requirements) and medical supervision (AD, for 5+ concurrent cases).

Misapplying these modifiers constitutes an incorrect claim. The same supervision-ratio logic applies to other anesthesia codes.

Qualifying circumstances that apply to CPT Code 00174

Qualifying circumstances are add-on codes reported alongside the primary anesthesia code when specific clinical conditions are present. They add modifying units to the billing formula. Each has strict clinical criteria; billing these codes without documentation support creates upcoding risk.

Add-on CodeDescriptionModifying Units Added
99100Anesthesia for patient of extreme age (under 1 year or over 70 years)1
99116Utilization of total body hypothermia5
99135Controlled hypotension during anesthesia5
99140Emergency conditions (patient’s life is at immediate risk)2

Code 99100 is the most frequently applicable for intraoral procedures, since pediatric and geriatric patients are common in this procedure category. The same add-on codes apply across the anesthesia code set.

The emergency code 99140 requires documentation that the patient’s life was at immediate risk, not merely that a procedure was performed urgently. Payer acceptance of qualifying circumstances varies; verify with each payer before reporting.

ICD-10 codes commonly linked to CPT Code 00174

Anesthesia codes are typically paired with the diagnosis code that describes the condition requiring the surgical procedure. For CPT Code 00174, the relevant ICD-10 diagnosis codes reflect the underlying pathology prompting the intraoral procedure or the retropharyngeal tumor excision.

Use the AAPC CPT-to-ICD-10 crosswalk to confirm medical necessity pairings for your payer’s LCD or NCD requirements. A benign nasopharyngeal mass, for example.

ICD-10 CodeDescriptionClinical Context
D10.6Benign neoplasm of nasopharynxExcision of a benign retropharyngeal/nasopharyngeal mass
C10.9Malignant neoplasm of oropharynx, unspecifiedExcision or biopsy confirming or staging an oropharyngeal/retropharyngeal malignancy
J39.0Retropharyngeal and parapharyngeal abscessSurgical drainage or excision in the retropharyngeal space
D10.30Benign neoplasm of unspecified part of mouthBiopsy of a benign intraoral mass
C06.9Malignant neoplasm of mouth, unspecifiedBiopsy confirming or staging an intraoral malignancy
K09.8Other cysts of oral region, not elsewhere classifiedExcision or biopsy of an intraoral cystic lesion

Always confirm ICD-10 pairings against your payer’s Local Coverage Determination (LCD) or National Coverage Determination (NCD) before claim submission. Diagnosis code documentation in the anesthesia record must support medical necessity — for example.

CPT 00174 vs. 00170: How the codes differ

CPT 00174 is frequently confused with the adjacent code CPT 00170. Both cover intraoral procedures, but CPT 00170 is the not-otherwise-specified (NOS) code for intraoral biopsy procedures, while CPT 00174 is reserved specifically for anesthesia during excision of a retropharyngeal tumor. Billing the wrong code is a frequent denial trigger in the head anesthesia range.

FeatureCPT 00170CPT 00174
DescriptorAnesthesia for intraoral procedures, including biopsy (not otherwise specified)Anesthesia for intraoral procedures, including biopsy; excision of retropharyngeal tumor
Base Units56
Key DifferentiatorGeneral intraoral biopsy procedures with no more specific applicable codeSpecific to excision of a retropharyngeal tumor
Selection GuidanceUse for intraoral biopsy procedures when no more specific code in the range appliesUse specifically when the operative note documents excision of a retropharyngeal tumor

The two codes differ by one base unit (5 for 00170 versus 6 for 00174), so reimbursement is slightly higher for 00174. The distinction matters most for medical necessity alignment: the ICD-10 diagnosis code paired with the claim should match the specific procedure described by the CPT code selected.

The operative note should clearly document a retropharyngeal tumor excision before 00174 is used instead of the NOS code 00170. For surgical procedure coding guidance across specialties.

Documentation requirements for CPT Code 00174

Clean claims for CPT Code 00174 require a complete anesthesia record. Missing or incomplete documentation is the most common reason for post-payment audit recoupment in the anesthesia code range. Maintaining HIPAA-compliant documentation practices is also a baseline requirement for all anesthesia claims.

  • Pre-anesthesia evaluation: documented assessment of the patient’s physical status (ASA physical status classification), allergies, medications, and relevant medical history
  • Anesthesia start and stop times: recorded to the minute; forms the basis for time unit calculation
  • Continuous monitoring record: vital signs, oxygen saturation, end-tidal CO2, and other monitoring parameters at timed intervals
  • Anesthesia technique: type of anesthesia administered (general, MAC, regional), agents used, and doses
  • Provider identification: CRNA, anesthesiologist, or medically directed team arrangement clearly documented
  • Medical necessity: documentation supporting the need for anesthesia for the specific intraoral procedure
  • Post-anesthesia note: patient condition at conclusion of anesthesia care

For practices using digital workflows. The same standardization matters whether anesthesia is coordinated at a surgical facility or through a private practice referring patients out for the procedure.

Practices that embed documentation prompts into their workflows report fewer missing-data denials on anesthesia claims.

Digital forms
Digital forms

Pro Tip

Audit your anesthesia records quarterly for missing start and stop times. A single missing time field converts a clean 00174 claim into a documentation deficiency, often resulting in a request for additional information or outright denial. Build a pre-submission checklist into your billing workflow to catch these issues before the claim leaves your practice.

How Pabau supports anesthesia billing and CPT Code 00174 management

Anesthesia billing practices that struggle with CPT Code 00174 denials often have a documentation problem, not a coding knowledge problem. Pabau’s claims management software includes a built-in CPT procedure code library, enabling billing teams to attach the correct code, modifiers, and supporting documentation at the point of care rather than reconstructing records after the fact.

Fully Integrated with Pabau Billing
Fully Integrated with Pabau Billing

For practices where anesthesiologists or CRNAs need to capture pre-anesthesia evaluation notes efficiently.

Surgical practices managing anesthesia coordination alongside procedural workflows benefit from surgical practice management tools that connect clinical and billing functions in a single system.

Reduce anesthesia claim denials with smarter documentation workflows

Pabau’s claims management software supports accurate CPT code submission with procedure code libraries, digital documentation, and built-in billing workflows designed for surgical and anesthesia practices.

Pabau claims management dashboard

CPT 00174 belongs to the head anesthesia code range, which covers procedures from the scalp through the oral cavity and facial structures.

Selecting the most specific applicable code within this range is required. Use the procedure documentation to determine the correct code rather than defaulting to the most familiar one.

CPT CodeDescriptionBase Units
00100Anesthesia for procedures on salivary glands, including biopsy5
00160Anesthesia for procedures on nose and accessory sinuses5
00170Anesthesia for intraoral procedures, including biopsy (not otherwise specified)5
00174Anesthesia for intraoral procedures, including biopsy; excision of retropharyngeal tumor6
00176Anesthesia for intraoral procedures; radical surgery7
00190Anesthesia for procedures on facial bones or skull5
00192Anesthesia for procedures on facial bones or skull; radical surgery (including prognathism)7

Radical intraoral surgery (00176) and radical surgery of facial bones or skull (00192) carry higher base units than CPT 00174, while non-radical facial bone procedures (00190) carry fewer. Billing CPT Code 00174 for a procedure that meets the descriptor for a higher-complexity code in this range is undercoding and reduces reimbursement.

Verify the surgical procedure note against the specific descriptor before selecting the anesthesia code.

Pro Tip

Cross-check the anesthesia code selection against the surgical CPT code on the claim. If the surgeon billed a code for radical surgery of facial bones or skull, radical intraoral surgery, or other facial bone work, and the anesthesiologist billed 00174 instead of 00176, 00190, or 00192, the mismatch is an audit flag. Coordinate code selection between the surgical and anesthesia billing teams before submission.

Conclusion

CPT Code 00174 is a precise tool for anesthesia billing on intraoral procedures, including excision of a retropharyngeal tumor. The most common failure points are modifier misselection (especially CRNA supervision modifiers), inadequate time documentation, and incorrect code selection when an adjacent code more accurately describes the procedure.

Practices that build CPT code libraries, modifier rules, and documentation checklists into their workflow at the point of care experience fewer denials than those that reconstruct records after the fact. Pabau’s claims management tools are designed for exactly that workflow. To see how it works in practice, book a demo with the Pabau team.

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Frequently asked questions

What does CPT Code 00174 cover?

CPT Code 00174 covers anesthesia services provided during intraoral procedures, including biopsy; excision of retropharyngeal tumor. It applies to anesthesiologists and CRNAs delivering anesthesia for retropharyngeal tumor excision and other intraoral surgical procedures, and falls within the CPT head anesthesia section (codes 00100-00222).

How many base units does CPT 00174 have?

CPT 00174 has 6 base units, as assigned by the American Society of Anesthesiologists. These represent the inherent complexity of the anesthesia service; time units and any applicable modifying units from qualifying circumstances are added to calculate total billable units.

Can a CRNA bill CPT Code 00174?

Yes, a CRNA can bill CPT Code 00174, with the appropriate modifier reflecting the supervision arrangement. Use modifier QZ for an independent CRNA, QX for a CRNA under medical direction, or QY when an anesthesiologist is directing exactly one CRNA. State law governs whether a CRNA may practice without physician direction; modifier selection must match the actual arrangement.

What modifiers are required for Monitored Anesthesia Care (MAC) billing with CPT 00174?

Medicare requires the QS modifier for all MAC claims, including CPT 00174. Modifier G8 is restricted by CMS to codes 00100, 00160, 00300, 00400, 00532, and 00920, so it does not apply to CPT 00174. Modifier G9 applies when the patient has a documented severe cardiopulmonary condition. Verify whether your commercial payers have additional MAC modifier requirements beyond Medicare’s QS mandate.

What qualifying circumstances apply to CPT 00174?

Add-on code 99100 (extreme age: under 1 year or over 70 years) is the most commonly applicable qualifying circumstance for intraoral procedures billed with CPT 00174. Code 99140 applies when the procedure is performed under emergency conditions. Each qualifying circumstance requires specific documentation support; billing these codes without adequate documentation creates upcoding exposure.

What is the difference between CPT 00170 and CPT 00174?

CPT 00170 is the not-otherwise-specified code for intraoral biopsy procedures and carries 5 base units, while CPT 00174 is specific to excision of a retropharyngeal tumor and carries 6 base units. Selection depends on the operative note: general intraoral biopsy with no more specific applicable code maps to 00170; excision of a retropharyngeal tumor maps to 00174.

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Alex Koch
Content Writer

Aleksandar is a content strategist and editor working in tech publishing, with a background in higher education. He specializes in topics around compliance in software solutions. When he's not writing at Pabau, you can find him tending to his bonsai collection or hitting the gym.
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