CPT code 00350 describes anesthesia services administered for surgical procedures involving the major vessels of the neck, not otherwise specified. It is the go-to code for anesthesiologists and certified registered nurse anesthetists (CRNAs) billing for anesthetic management during complex neck vascular operations — most notably carotid endarterectomy, carotid artery repair, and related open vascular interventions on the jugular vein or subclavian vessels at the neck level. With a base unit value of 10 assigned by the Centers for Medicare & Medicaid Services (CMS), 00350 sits among the higher-intensity anesthesia codes in the neck and head range, reflecting the hemodynamic complexity and neurological monitoring demands of these cases.
This guide is written for medical billers, anesthesia coders, revenue cycle professionals, and compliance auditors who need practitioner-level clarity on when to apply 00350, how to document it, how Medicare and commercial payers reimburse it, and how to avoid the most common billing errors that trigger denials and RAC review.
What Does CPT Code 00350 Mean?
CPT 00350 is defined as: Anesthesia for procedures on major vessels of neck; not otherwise specified. This descriptor language — specifically the phrase “not otherwise specified” (NOS) — is the key differentiator that determines when this code applies versus a more specific neck vascular anesthesia code.
Key attributes of CPT 00350:
- Billable status: Active; reportable by anesthesiologists, CRNAs, and anesthesiologist assistants
- Applicable setting: Hospital inpatient (facility) and outpatient surgical settings
- Provider type: Anesthesia professionals — not the operating surgeon
- Service category: Anesthesia for procedures on major vessels of neck (CPT range 00320–00352)
- CMS base unit value: 10 base units (unchanged for CY 2025 and CY 2026)
- Code status: Descriptor updated effective January 1, 2026 per the AMA CPT code set revision cycle
What Procedures and Surgical Services Does CPT 00350 Cover?
CPT 00350 applies when an anesthesia provider delivers anesthesia services — whether general anesthesia, regional anesthesia, or monitored anesthesia care (MAC) — for surgical procedures performed on the major blood vessels located in the neck. The code captures a broad clinical landscape under its NOS umbrella.
Procedures and presentations commonly covered by 00350 include:
- Carotid endarterectomy (CEA) — open surgical removal of atherosclerotic plaque from the carotid artery (most common pairing; the associated surgical code is typically CPT 35301)
- Carotid artery repair or reconstruction — including patch angioplasty of the internal or common carotid artery
- Resection or repair of cervical vascular tumors — such as carotid body tumor excision involving major neck vessels
- Jugular vein ligation or repair — when performed in a surgical context involving major vascular structures
- Carotid artery aneurysm repair — open surgical approaches at the neck level
- Subclavian artery procedures — at the neck access point, when not better described by a more specific code
- Vascular trauma repair of neck vessels — emergent or urgent open repair of major cervical vascular injuries
- Lymph node dissection with major vascular involvement — when the major neck vessels are the primary operative focus for anesthesia risk
What Does CPT 00350 Specifically Exclude?
Not every neck procedure qualifies for 00350. Correct code selection requires understanding its boundaries:
- CPT 00352 (anesthesia for major vessels of neck, simple ligation) — a separate, lower-complexity code with only 5 base units, applying when the procedure is limited to simple ligation of a major neck vessel; if the procedure goes beyond simple ligation, 00350 is appropriate
- CPT 00300 — covers anesthesia for the integumentary system, muscles, and nerves of the head, neck, and posterior trunk; applies when the procedure does not involve the major vasculature
- CPT 00320 / 00322 — these codes apply to anesthesia for procedures on the esophagus, thyroid, larynx, trachea, and lymphatics of the neck; if the major vessels are not the operative target, 00320 or 00322 may be more precise
- CPT 01925 / 01926 — apply to therapeutic interventional radiology procedures involving the carotid artery or intracranial arteries; these are the correct codes for percutaneous (endovascular) approaches, not open surgical ones
- Anesthesia services for the operating surgeon’s own procedures — 00350 is reported by the anesthesia team only, not the vascular surgeon
When Is CPT 00350 the Right Code to Use?
Selecting 00350 correctly depends on a clear understanding of the procedure’s anatomical target, the approach (open vs. endovascular), and whether a more specific code in the series exists. In practice, anesthesia coders for busy vascular surgery practices deal with this selection question on a near-daily basis.
Follow this step-by-step selection process:
- Confirm the operative target is a major neck vessel. The carotid arteries (common, internal, external), jugular veins, and subclavian vessels at the cervical level are the primary qualifying structures. If the procedure targets soft tissue, lymph nodes, thyroid, or nerves without major vascular involvement, look to 00300 or 00320 first.
- Determine the surgical approach. If the procedure is open/surgical (incision-based), stay in the 00350–00352 range. If the approach is percutaneous or endovascular (catheter-based), review codes 01924–01926 for interventional radiology anesthesia.
- Assess procedure complexity. Ask whether the procedure involves more than simple ligation. If the surgeon is performing endarterectomy, repair, reconstruction, aneurysmorrhaphy, or excision with vascular control, 00350 (NOS) is appropriate. If only simple ligation is documented, 00352 applies.
- Verify “NOS” eligibility. The NOS descriptor means no more-specific code in the AMA CPT schedule applies. If you find a more specific code that precisely describes the anesthesia service, use it instead.
- Confirm anesthesia was personally provided or medically directed. Determine the provider delivery model — personally performed, medically directed (2–4 concurrent), or supervised — as this drives modifier selection.
- Apply appropriate physical status modifier. Document and append P1–P5 based on the anesthesiologist’s pre-anesthesia assessment of the patient’s systemic health status.
How Does CPT 00350 Differ From CPT 00352?
The 00350/00352 distinction is one of the most frequent code selection questions in anesthesia billing for neck vascular cases.
| Feature | CPT 00350 | CPT 00352 |
|---|---|---|
| Descriptor | Major vessels of neck; NOS | Major vessels of neck; simple ligation |
| Base Units (CMS) | 10 | 5 |
| Procedure complexity | Complex vascular work (CEA, repair, reconstruction) | Simple ligation only |
| Typical surgical partner | CPT 35301 (CEA), vascular repair codes | Ligation of a bleeding neck vessel |
| Reimbursement impact | Higher (more units) | Lower (fewer units) |
| Typical clinical context | Elective or urgent vascular surgery | Emergency hemorrhage control or incidental ligation |
When the operative report documents simple ligation and nothing more, use 00352. Any additional vascular work elevates the encounter to 00350.
What Documentation Is Required to Support CPT 00350?
Anesthesia billing documentation requirements differ meaningfully from evaluation and management (E&M) coding. Reimbursement for 00350 flows from a time-and-unit formula, not a complexity-of-visit framework — but the documentation must substantiate both the anesthesia time and the clinical rationale for the code.
What Must the Provider Document in the Anesthesia Record?
The anesthesia record and pre-/post-procedure notes must contain all of the following to support a clean 00350 claim:
- Pre-anesthesia evaluation — completed before the procedure begins; documents the patient’s relevant medical history, airway assessment, and physical status classification (P1–P5/P6)
- Anesthesia start time — the moment the anesthesiologist begins preparing the patient for anesthesia in the operating room or equivalent area; this is the billing start point under CMS Medicare Claims Processing Manual, Chapter 12, Section 50
- Anesthesia end time — when the anesthesiologist is no longer in personal attendance and the patient can safely be placed under postoperative supervision (typically PACU handoff); this is the billing end point
- Type of anesthesia administered — general, regional (e.g., cervical plexus block), or MAC; type influences clinical context but not base unit value for 00350
- Name of the surgical procedure performed — must align with a procedure on the major vessels of the neck to justify 00350; the operative report from the surgeon should corroborate this
- Physical status modifier — documented in the pre-anesthesia assessment and reflected on the claim (e.g., P3 for severe systemic disease)
- Intraoperative monitoring notations — particularly relevant for carotid cases where electroencephalography (EEG) or somatosensory evoked potential (SSEP) monitoring is used; while separate codes apply for monitoring services, the anesthesia record should reflect the clinical complexity
- Post-anesthesia note — documenting the patient’s condition at time of transfer and any post-anesthesia complications
How Is Anesthesia Time Correctly Reported for CPT 00350?
Accurate time documentation is the foundation of anesthesia reimbursement. Key rules:
- Pre-anesthesia assessment time is not billable — it is considered incorporated into the base unit value
- Anesthesia time begins when patient preparation in the OR starts — not when incision occurs
- Anesthesia time ends at PACU handoff or equivalent — not at surgical closure
- Most payers, including Medicare, calculate time in 15-minute increments (1 time unit = 15 minutes); some commercial payers use different increments — verify payer contracts
- Time must be documented in minutes on the anesthesia record; start/stop times should appear in Box 19 or on an electronic claim attachment
How Does CPT 00350 Affect Medical Billing and Reimbursement?
Anesthesia billing does not follow the standard RVU-conversion-factor formula used for surgical and E&M services. Instead, reimbursement is calculated using the anesthesia billing formula: (Base Units + Time Units + Qualifying Circumstance Units) × Anesthesia Conversion Factor = Allowable Amount.
CPT 00350 Reimbursement Components
| Reimbursement Component | CPT 00350 Value / Rule |
|---|---|
| CMS Base Units | 10 |
| Time Units | 1 unit per 15 minutes of anesthesia time (most payers) |
| Physical Status Units | P1: 0; P2: 0; P3: +1; P4: +2; P5: +3 (payer-specific; Medicare does not add units for PS) |
| Qualifying Circumstance Codes | 99100 (+1 unit for age extremes), 99140 (+2 units for emergency) — billed separately |
| CY 2026 Medicare Anesthesia CF (standard) | $20.4976 per unit |
| CY 2026 Medicare Anesthesia CF (APM-qualified) | $20.5998 per unit |
Worked example: A P3 patient undergoes carotid endarterectomy. Anesthesia time is 105 minutes (7 time units). The anesthesiologist personally performs the service (modifier AA). Base units: 10. Time units: 7. Physical status units (commercial payer adds P3): 1. Total: 18 units. At a commercial conversion factor of $100/unit (illustrative), the charge is $1,800. Under Medicare’s 2026 standard CF of $20.4976, the Medicare allowable at 17 units (Medicare does not add P3 units) would be approximately $348.46.
According to the CMS Anesthesiologists Center, the anesthesia base units for CPT 00350 have remained unchanged at 10 for CY 2025 and CY 2026. The 2026 anesthesia conversion factor represents a 0.88% increase over 2025’s rate of $20.3178 for non-APM participants.
Additional billing considerations:
- All anesthesia claims must include an anesthesia payment modifier (AA, QY, QK, AD, QX, or QZ) — claims submitted without a payment modifier will be denied as a billing error
- The highest base unit value controls when multiple procedures are performed during the same anesthetic
- Commercial payer conversion factors vary significantly by locality and contract terms; verify your MAC locality factor or contracted rate for accurate projections
What Modifiers Are Commonly Used With CPT 00350?
| Modifier | Description | When to Apply | Billing Impact |
|---|---|---|---|
| AA | Anesthesia services personally performed by anesthesiologist | Solo anesthesiologist personally provides the complete anesthetic | Full allowable (100%) |
| QY | Medical direction of one CRNA by an anesthesiologist | Anesthesiologist directs a single CRNA | 50% of allowable to each provider |
| QK | Medical direction of 2–4 concurrent procedures | Anesthesiologist directing 2–4 cases simultaneously | 50% of allowable per case |
| AD | Medical supervision (5 or more concurrent cases) | Anesthesiologist overseeing 5+ cases | Three base units per case maximum |
| QX | CRNA with medical direction by a physician | CRNA’s claim when medically directed | 50% of allowable |
| QZ | CRNA without medical direction | Independent CRNA practice (opt-out states) | Full CRNA allowable |
| P1–P5 | Physical status modifiers | All anesthesia claims (P6 = brain-dead organ donor) | May add units (payer-specific) |
| 99100 | Qualifying circumstance: extreme age | Patient under 1 year or over 70 (some payers) | Adds qualifying units |
| 99140 | Qualifying circumstance: emergency | Documented medical emergency | Adds qualifying units |
| 23 | Unusual anesthesia | Anesthesia required for service normally not needing it | Additional documentation required |
In practice: Claims submitted for CPT 00350 with modifier AA are the most straightforward to adjudicate. The most common denial scenario anesthesia billing teams encounter involves submitting both QY (physician’s claim) and QX (CRNA’s claim) without ensuring the modifier pair is consistent — payers will reject the pair if they don’t align.
Are There Prior Authorization, Coverage Restrictions, or NCCI Requirements for CPT 00350?
- Medicare coverage: CPT 00350 is a covered Medicare Part B service when medical necessity is established (typically through the surgical diagnosis, such as I65.21 — occlusion and stenosis of right carotid artery, or I65.22 for left); no prior authorization is required for Medicare
- Commercial payer variation: Some commercial plans require prior authorization for elective carotid endarterectomy; anesthesia authorization may be tied to the surgical authorization — verify payer-by-payer
- No NCD or LCD specifically for 00350: Coverage is generally established through the underlying surgical procedure’s medical necessity; the anesthesia code follows the surgical code
- NCCI bundling: The anesthesia code 00350 is not typically bundled with the surgical code (e.g., 35301) on the anesthesiologist’s claim — anesthesia and surgical claims are submitted by different providers; bundling edits are most relevant when a single provider bills both
- Global period: CPT 00350 has no global period (indicator: XXX); post-anesthesia care unit (PACU) management is generally included in the anesthesia service
What CPT or HCPCS Codes Are Commonly Billed Alongside CPT 00350?
The anesthesia code 00350 is always reported on the anesthesiologist’s claim, while the surgeon files a separate claim with the procedural code. The following codes commonly appear in the same episode of care:
| Associated Code | Description | Typical Pairing Context | Bundling Risk |
|---|---|---|---|
| 35301 | Thromboendarterectomy, carotid artery by neck incision | Primary surgical code for CEA; reported by surgeon | No (separate providers) |
| 35390 | Reoperation of carotid artery, add-on | Staged or redo CEA; surgeon’s claim | No |
| 93882 | Duplex scan of extracranial arteries; unilateral | Post-CEA vascular evaluation | No |
| 95920 | Intraoperative neurophysiologic testing (e.g., SSEP, EEG) | Often performed by neurophysiology team during CEA | Monitor for bundling if same provider |
| 36620 | Arterial catheterization (A-line placement) | Invasive hemodynamic monitoring during neck vascular cases | Yes — bundled with anesthesia services (see below) |
| 99100 | Qualifying circumstance: extreme age | Appended for patients under 1 or over 70 when supported | No (add-on service) |
| 99140 | Qualifying circumstance: emergency | Appended when the case is an emergent neck vascular procedure | No (add-on service) |
Which Code Combinations Trigger NCCI or CCI Edits?
Arterial and venous access lines placed for monitoring purposes during anesthesia are the most frequently bundled services:
- Arterial line placement (36620) — CMS and most major commercial payers bundle routine arterial line placement into the anesthesia service; separate billing is not appropriate unless documentation supports a distinct, separately identifiable clinical service
- Central venous catheterization (36555–36556) — similarly bundled if performed as routine anesthesia management; may be separately billable if performed for an independent therapeutic reason with distinct documentation
- Swan-Ganz catheter placement (93503) — typically bundled; requires strong separate medical justification to bill in addition to 00350
- Intraoperative nerve monitoring (95920) — not bundled when performed by an independent neurophysiology provider; bundled if the anesthesiologist personally provides the monitoring service
The CMS National Correct Coding Initiative (NCCI) Policy Manual, Chapter 1, provides foundational guidance on which services are considered integral to anesthesia and therefore not separately reportable.
What Coding Errors Should You Avoid With CPT 00350?
Anesthesia coding for neck vascular procedures has a concentrated set of error patterns. Revenue cycle teams auditing 00350 claims should prioritize the following:
- Billing 00350 for endovascular/interventional procedures — carotid artery stenting (CAS) performed percutaneously is not an open vascular procedure; anesthesia for those cases belongs in the 01924–01926 range (therapeutic interventional radiology anesthesia codes)
- Using 00350 when 00352 is correct — if the operative report documents only simple ligation without endarterectomy, reconstruction, or repair, 00350 overstates the procedure; 00352 (5 base units) is the accurate code and the difference will be challenged on audit
- Incorrect anesthesia start and stop time documentation — the most common driver of time unit discrepancies; pre-anesthesia assessment time before the patient enters the OR is not billable time under the standard anesthesia formula
- Missing or mismatched payment modifier — submitting 00350 without an AA, QK, QY, QX, QZ, or AD modifier results in automatic denial from most payers; submitting QY and QX with inconsistent physician/CRNA pairings creates cross-claim adjudication errors
- Failing to separately bill qualifying circumstance codes — 99100 and 99140 are separately reportable add-on services when documented; leaving them off leaves revenue on the table
- Applying physical status modifiers inconsistently — the physical status classification must be supported by the pre-anesthesia evaluation; appending P4 or P5 without documented severe systemic disease creates audit exposure
- Billing 00350 on the surgeon’s claim — this code belongs exclusively to the anesthesia provider’s CMS-1500 or electronic claim; the surgeon bills the surgical procedure code (e.g., 35301)
What Do Auditors and RAC Reviewers Look for When Reviewing Claims With CPT 00350?
RAC (Recovery Audit Contractor) and MAC post-payment reviews of anesthesia claims for neck vascular procedures typically focus on:
- Anesthesia time documentation — do the start/stop times in the anesthesia record match what was billed? Time unit inflation (billing more units than elapsed time supports) is a top audit trigger
- Procedure-code alignment — does the surgical procedure code on the surgeon’s claim match a procedure involving the major vessels of the neck? A CEA (35301) paired with 00350 is appropriate; a thyroidectomy (60240) paired with 00350 is a mismatch
- Physical status substantiation — P3 and above must be supported by specific clinical findings in the pre-anesthesia assessment; unsupported high physical status modifiers in commercial claims increase units and payment
- Concurrent case count and modifier accuracy — for medically directed cases, auditors verify that the anesthesiologist’s medical direction documentation (the “5 steps” required by Medicare) is present and contemporaneous
- Qualifying circumstance code support — 99100 and 99140 must be separately documented and medically justified; auditors check for rote appending without clinical basis
How Does CPT 00350 Relate to Other Anesthesia CPT Codes for the Neck?
Understanding 00350 within its code family allows coders to navigate the neck anesthesia range with precision.
| Related Code | Relationship Type | Key Distinction |
|---|---|---|
| 00300 | Alternative (non-vascular neck) | Covers skin, muscles, nerves of neck — not major vessels |
| 00320 | Alternative (neck organs) | Esophagus, thyroid, larynx, trachea, lymphatics — not major vessels |
| 00322 | Alternative (thyroid biopsy) | Needle biopsy of thyroid; very low complexity (3 base units) |
| 00326 | Alternative (pediatric airway) | Larynx/trachea in children under 1 year |
| 00352 | Sibling code (simpler) | Major vessels of neck, simple ligation only (5 base units) |
| 01925 | Substitute (endovascular carotid) | Therapeutic interventional radiology — carotid artery |
| 00216 | Related (intracranial vessels) | Vessel surgery of the head/brain, not neck level |
| 99100 | Add-on (qualifying circumstance) | Extreme age; added to 00350 when applicable |
| 99140 | Add-on (qualifying circumstance) | Emergency conditions; added to 00350 when applicable |
What Is the Correct Code Sequencing When CPT 00350 Appears With Other Codes?
Anesthesia code sequencing rules differ from standard CPT sequencing:
- When multiple procedures are performed under one anesthetic, the anesthesia code with the highest base unit value is the one billed — not multiple anesthesia codes. If the carotid endarterectomy (00350, 10 units) is performed alongside a shoulder procedure (e.g., 01610, 6 units) in the same anesthetic session, only 00350 is reported.
- Qualifying circumstance codes (99100, 99140) are reported in addition to 00350 on the same claim when applicable — they are not alternatives to the primary anesthesia code.
- Physical status modifiers are appended directly to 00350 on the claim line (e.g., 00350-P3-AA).
- Payment modifiers (AA, QK, etc.) are also appended to the 00350 line; most billing systems sequence modifiers as payment modifier first, then physical status (e.g., 00350-AA-P3).
- ICD-10-CM diagnosis codes establish medical necessity; the primary diagnosis should reflect the condition requiring the surgical procedure (e.g., I65.21 for carotid stenosis), and secondary diagnoses capturing the patient’s comorbid conditions support physical status assignment.
Real-World Coding Scenario — How CPT 00350 Is Applied in Practice
Clinical scenario: A 71-year-old male with hypertension, hyperlipidemia, and symptomatic 80% left internal carotid artery stenosis presents for elective left carotid endarterectomy. The anesthesiologist performs a pre-anesthesia evaluation, classifies the patient as P3, and personally provides general anesthesia with intraoperative SSEP monitoring performed by a separate neurophysiology team. Anesthesia begins at 7:22 AM when the patient’s IV and monitoring lines are placed in the OR. The surgeon completes the procedure and the patient is transferred to PACU at 10:17 AM. Total anesthesia time: 175 minutes.
Correct Code Application
- 00350-AA-P3 — CPT 00350 for major neck vessel surgery, NOS; modifier AA (personally performed); modifier P3 (severe systemic disease — hypertension and significant carotid disease); billed by the anesthesiologist
- Time units: 175 minutes ÷ 15 = 11.67 → 11 full time units (or 12 if the payer rounds up; verify payer-specific rounding policy)
- Total units (commercial payer adding P3): 10 (base) + 11 (time) + 1 (P3) = 22 units
- Qualifying circumstance 99100 — patient is 71; over 70 years; report separately if the payer recognizes it (verify payer contract)
- 35301-LT — billed by the vascular surgeon on a separate claim; anesthesia coder does not report this
Common Mistakes in This Scenario
- Billing 01925 instead of 00350 — 01925 applies to endovascular carotid interventions (stenting); this was an open CEA, making 00350 correct
- Omitting the payment modifier (AA) — submitting 00350 without AA would result in a modifier-missing denial
- Reporting 95920 by the anesthesiologist — since the neurophysiology monitoring was performed by a separate independent team, the anesthesiologist should not bill 95920; that claim belongs to the neurophysiology provider
- Double-billing 00350 on the surgeon’s claim — a vascular surgery practice that also employs CRNAs must ensure clear delineation of billing entities; the surgeon’s claim carries 35301, not 00350
Frequently Asked Questions About CPT Code 00350
Is CPT Code 00350 Valid for Use in 2026?
CPT code 00350 remains an active, billable anesthesia code for calendar year 2026. Per the AMA CPT code set, the code’s short and medium descriptors were updated effective January 1, 2026, but the code itself was not deleted, replaced, or substantively altered in its clinical meaning. Anesthesia coders should verify annually against the AMA CPT Professional Edition and the CMS anesthesia base unit table to confirm no further revisions have been applied. As of CY 2026, the base unit value of 10 remains unchanged.
What Is the Difference Between CPT 00350 and CPT 00352?
CPT 00350 applies to anesthesia for any procedure on the major vessels of the neck that is not otherwise specified — meaning it covers complex open vascular procedures such as carotid endarterectomy, carotid repair, and aneurysm resection. CPT 00352 is a more specific code applying only when the procedure is a simple ligation of a major neck vessel. The base unit value for 00350 is 10, compared to 5 for 00352, reflecting the higher anesthetic complexity of NOS neck vascular procedures. When in doubt, the operative report’s description of the procedure drives the selection.
How Is Anesthesia Time Calculated and Billed for CPT 00350?
Anesthesia time begins when the anesthesiologist begins preparing the patient in the operating room and ends when personal attendance is no longer required — typically at PACU handoff. Time is converted to units, usually in 15-minute increments (1 unit per 15 minutes), and added to the base units before multiplying by the conversion factor. The formula is: (Base Units + Time Units) × Conversion Factor = Medicare Allowable. Under the 2026 Medicare anesthesia conversion factor of $20.4976 (for non-APM participants), a case with 17 total units would yield a Medicare allowable of approximately $348.46. Commercial payer conversion factors and rounding methodologies vary and should be verified against contracted rates.
What Payment Modifier Is Required When Billing CPT 00350?
Every anesthesia claim — including 00350 — must include an anesthesia payment modifier indicating the provider’s role. An anesthesiologist performing the case personally reports modifier AA. When the anesthesiologist medically directs a CRNA in a single concurrent case, the physician reports QY and the CRNA reports QX. For 2–4 concurrent medically directed cases, the physician reports QK and each CRNA reports QX. An independent CRNA in an opt-out state reports QZ. Submitting 00350 without one of these payment modifiers results in automatic claim denial under CMS policy effective for dates processed after July 1, 2018.
Does Medicare Recognize Physical Status Modifiers for CPT 00350?
Medicare does not recognize physical status modifiers (P1–P5) for additional payment purposes — they do not add units to the anesthesia calculation on Medicare claims. However, physical status modifiers should still be appended to the claim for informational and documentation purposes. Many commercial payers and Medicaid programs do recognize physical status modifiers and will add 1–3 units depending on the documented classification. Review each payer’s specific anesthesia policy before applying physical status units to commercial claims.
Can CPT 00350 Be Billed for Endovascular Carotid Artery Stenting?
No. CPT 00350 applies exclusively to open surgical procedures on the major vessels of the neck. Anesthesia for percutaneous, catheter-based carotid artery interventions — including carotid artery stenting (CAS) — should be reported using CPT 01925 (anesthesia for therapeutic interventional radiological procedures involving the carotid artery). Using 00350 for an endovascular approach would be a misrepresentation of the service and a common audit target for payers that cross-reference anesthesia and surgical claim codes.
What Diagnosis Codes Support CPT 00350 for Carotid Artery Surgery?
The most common ICD-10-CM codes paired with CPT 00350 for carotid endarterectomy include I65.21 (occlusion and stenosis of right carotid artery), I65.22 (occlusion and stenosis of left carotid artery), I65.23 (bilateral), and I65.29 (other specified). Secondary diagnoses documenting comorbidities such as hypertension (I10), diabetes mellitus (E11.9), and peripheral artery disease (I73.9) strengthen medical necessity and support appropriate physical status coding. For traumatic vascular injuries, injury codes from the S15 range (injuries of blood vessels at neck level) apply.
Key Takeaways for Billing and Coding CPT 00350
Every anesthesia coder and revenue cycle professional working with neck vascular surgery cases should keep these core principles close:
- CPT 00350 applies to anesthesia for open surgical procedures on the major vessels of the neck; it is not appropriate for endovascular approaches (use 01925 instead)
- The code carries 10 CMS base units — double the 5 units assigned to the closely related 00352 (simple ligation); always confirm the operative report before selecting between them
- All 00350 claims require an anesthesia payment modifier (AA, QK, QY, QX, QZ, or AD) — missing modifiers are the single most common cause of denial for this code
- The 2026 CMS anesthesia conversion factor is $20.4976 for non-APM participants and $20.5998 for Qualifying APM Participants — a modest 0.88% increase over 2025
- Anesthesia time starts in the OR when patient preparation begins, not at surgical incision; accurate start/stop documentation is the foundation of defensible time unit billing
- Medicare does not pay additional units for physical status modifiers; many commercial payers do — verify payer-by-payer before including P-modifier units in your billing calculation
- Routine arterial line and central line placement are bundled into anesthesia services and are generally not separately reportable alongside 00350
For current anesthesia conversion factor data, verify the most up-to-date values on the CMS Anesthesiologists Center page at cms.gov and in the Medicare Claims Processing Manual, Chapter 12, Section 50. The American Society of Anesthesiologists (ASA) Relative Value Guide (RVG) is the industry-standard reference for anesthesia base unit values, including 00350, and should be consulted alongside the CMS base unit table for practice-level pricing decisions.
For a broader understanding of anesthesia modifier billing rules, NCCI bundling edits, and revenue cycle compliance strategies in vascular surgery anesthesia practices, cross-reference your payer contracts and the CMS National Correct Coding Initiative (NCCI) Policy Manual Chapter 1, which governs which services are integral to — and therefore non-separately-reportable with — anesthesia.
