CPT code 00402 describes anesthesia services for reconstructive procedures on the breast, including surgeries such as reduction mammoplasty, augmentation mammoplasty, and muscle flap reconstruction. It belongs to the integumentary system anesthesia code family (range 00400–00410) and carries 5 base units as established by the American Society of Anesthesiologists (ASA) Relative Value Guide. Accurate application of this code requires understanding its specific procedural scope, the anesthesia time-plus-base-unit payment model, required provider role modifiers, and how it differs from adjacent codes covering radical breast procedures.
What Does CPT Code 00402 Mean?
CPT 00402 is the anesthesia code for reconstructive procedures on the breast involving the integumentary system of the anterior trunk. Its full AMA descriptor reads: Anesthesia for procedures on the integumentary system on the extremities, anterior trunk and perineum; reconstructive procedures on breast (eg, reduction or augmentation mammoplasty, muscle flaps).
Key attributes of this code at a glance:
- Code type: Standalone anesthesia procedure code (CPT range 00100–01999)
- ASA base units: 5
- Service setting: Facility (hospital inpatient, hospital outpatient, ambulatory surgical center)
- Provider types: Anesthesiologist (MD/DO), Certified Registered Nurse Anesthetist (CRNA), Anesthesiologist Assistant (AA)
- Reimbursement method: Time-based (base units + time units × conversion factor)
- Medicare coverage: Yes, subject to medical necessity and local MAC policy
What Procedures Does CPT 00402 Cover?
CPT 00402 encompasses anesthesia services provided during a defined set of reconstructive breast operations. The parenthetical examples in the descriptor are illustrative, not exhaustive — coders should apply this code to any breast reconstructive case that does not meet the descriptor criteria for CPT 00404 or 00406.
Procedures appropriately covered by 00402 include:
- Reduction mammoplasty (CPT 19318) — surgical reduction of breast volume and reshaping
- Augmentation mammoplasty (CPT 19325) — insertion of breast implants for cosmetic or reconstructive purposes
- Immediate or delayed implant placement (CPT 19340, 19342) — implant insertion on the same or separate day from mastectomy
- Tissue expander placement (CPT 19357) — for staged breast reconstruction post-mastectomy
- Latissimus dorsi (LD) muscle flap reconstruction (CPT 19361) — pedicled flap using the back muscle
- Nipple and areola reconstruction (CPT 19350) — commonly performed as a staged procedure
- Revision of peri-implant capsule (CPT 19370) — capsulotomy, capsulorrhaphy, or partial capsulectomy
- Mastopexy (CPT 19316) — breast lift without implant
What Does CPT 00402 Specifically Exclude?
Not all breast surgical procedures fall under 00402. The following scenarios require a different anesthesia code:
- Radical or modified radical mastectomy without node dissection → use CPT 00404
- Radical or modified radical mastectomy with internal mammary node dissection → use CPT 00406 (13 base units — significantly higher complexity)
- Simple, complete mastectomy or partial mastectomy → assess whether 00404 is the better match depending on surgical scope
- Biopsy procedures only → consider CPT 00400 (skin, extremities, anterior trunk, perineum — general)
- Anesthesia for needle biopsy of breast — some payers assign 00400; verify with payer policy
When Is CPT 00402 the Right Code to Use?
In practice, anesthesia coders frequently encounter cases where the surgical CPT code exists but the anesthesia code must be identified separately using the ASA Crosswalk®. The starting point is always the operative report — confirm the surgical CPT code(s), then map to the appropriate anesthesia code.
Apply CPT 00402 when all of the following criteria are met:
- The surgical procedure is reconstructive in nature — it reshapes, restores, or augments the breast rather than removing breast tissue as the primary intent.
- The anesthesia is provided on the anterior trunk — breast surgery falls within the integumentary system, anterior trunk category.
- The procedure does not involve radical or modified radical dissection — those cases step up to 00404 or 00406.
- General or regional anesthesia is administered — monitored anesthesia care (MAC) may apply in limited circumstances; append modifier QS if MAC is used.
- The surgical CPT code maps to 00402 via the ASA Crosswalk® — confirm the crosswalk match before coding, particularly for newer breast reconstruction codes introduced since 2021.
- The anesthesia provider is qualified and credentialed for the service setting (hospital, ASC, or office-based OR).
How Does CPT 00402 Differ From 00404 and 00406?
This is one of the most common coding questions in breast anesthesia billing. The distinctions hinge on the type of breast surgery performed, not the depth of anesthesia.
| Code | Descriptor Focus | Base Units | Typical Surgical CPT Crosswalk |
|---|---|---|---|
| 00402 | Reconstructive procedures (augmentation, reduction, flaps) | 5 | 19318, 19325, 19340, 19342, 19357, 19361 |
| 00404 | Radical or modified radical procedures on breast | 5 | Simple/total mastectomy procedures |
| 00406 | Radical or modified radical procedures with internal mammary node dissection | 13 | Extended radical mastectomy with node dissection |
Billing teams in breast surgery practices frequently ask whether a “nipple-sparing mastectomy with immediate implant” should be coded 00402 or 00404. The answer depends on the primary surgical intent: if the dominant procedure is the mastectomy, use 00404; if the dominant procedure is reconstruction (and the mastectomy was already separately performed), use 00402. When both occur in the same operative session, apply the ASA multi-procedure rule: report only the single anesthesia code with the highest base unit value and add total time across all procedures.
What Documentation Is Required to Support CPT 00402?
Anesthesia documentation is distinct from surgical operative reports. The anesthesia record is the primary evidentiary document for claims adjudication, audit defense, and medical necessity review.
What Must the Anesthesia Provider Document?
The following elements are required on the anesthesia record to support CPT 00402:
- Patient identification and date of service — confirmed pre-operatively
- Surgical procedure performed — recorded as dictated by the surgeon; this anchors the anesthesia code crosswalk
- Anesthesia start and stop times — recorded in minutes; time is the variable that drives reimbursement above the base units
- Type of anesthesia administered — general, regional, neuraxial, or MAC (MAC requires modifier QS)
- Physical status classification — documented using the ASA Physical Status scale (P1–P6), supported by the pre-anesthesia assessment
- Pre-anesthesia evaluation — completed before induction, documenting relevant comorbidities, medications, allergies, and airway assessment
- Intra-operative monitoring notations — vital signs at regular intervals, anesthetic agents, dosages, and any intra-operative events
- Provider identity and role — name, credentials, NPI, and role (personally performed, medically directing, or independent CRNA)
- Post-anesthesia care unit (PACU) handoff note — confirms patient transfer and initial recovery status
- Qualifying circumstances notation (if applicable) — explicit documentation supporting use of add-on codes 99100, 99135, or 99140
What Are the Facility vs. Non-Facility Documentation Considerations?
Breast reconstructive surgery under CPT 00402 is almost exclusively performed in a facility setting, but documentation expectations differ by venue:
Hospital Inpatient / Hospital Outpatient (HOD/HOPD):
- Full anesthesia record captured in the hospital’s electronic health record (EHR)
- Pre-anesthesia H&P performed and co-signed if delegated
- Facility fee billed separately under OPPS; the anesthesia professional bills the professional fee only
Ambulatory Surgical Center (ASC):
- Shorter cases (augmentation, mastopexy) increasingly performed in ASC settings
- Same documentation standards apply; time must be tracked to the minute
- ASC does not pay the anesthesia professional fee — the group bills CMS-1500 separately
Office-Based Operating Room:
- Relatively uncommon for major flap reconstructions; more typical for minor procedures
- Payers may impose additional credentialing or safety documentation requirements
- Confirm payer policy before billing office-based anesthesia for reconstructive cases
How Does CPT 00402 Affect Anesthesia Billing and Reimbursement?
Unlike most medical and surgical CPT codes that reimburse on an RVU-based fee schedule, anesthesia codes use a base unit + time unit formula:
Payment = (Base Units + Time Units + Qualifying Circumstance Units) × Conversion Factor
For CPT 00402, the foundation of every claim is the 5 base units assigned by the ASA. Time units are calculated by dividing total anesthesia minutes by 15 (one time unit per 15 minutes is the Medicare standard; some commercial payers use 10- or 12-minute increments).
| Component | Value for CPT 00402 |
|---|---|
| ASA Base Units | 5 |
| Time Unit Interval (Medicare) | 1 unit per 15 minutes |
| Medicare Anesthesia Conversion Factor (2024) | ~$21.56 per unit |
| Physical Status Units (commercial payers) | P3 = +1; P4 = +2; P5 = +3 |
| Qualifying Circumstance Units (non-Medicare) | 99100 = +1; 99135 = +5; 99140 = +2 |
Illustrative reimbursement example (Medicare): A 90-minute augmentation mammoplasty case billed with CPT 00402-AA-P1 yields: 5 base units + 6 time units (90 ÷ 15) = 11 total units × $21.56 = approximately $237.16. Commercial payers using a higher conversion factor (median ~$78.00 in 2022 per ASA survey data) for the same case would yield approximately $858.00. The disparity underscores why contract management matters in anesthesia billing.
Per the CMS Medicare Claims Processing Manual, Chapter 12, Section 50, Medicare determines anesthesia payment using allowed base units, actual time, and a locality-specific conversion factor published by the MAC.
What Modifiers Are Required With CPT 00402?
Every anesthesia claim submitted to Medicare and most commercial payers requires at least one provider role modifier. Failure to append the appropriate modifier results in claim rejection.
| Modifier | Description | Who Reports It | Reimbursement Impact |
|---|---|---|---|
| AA | Anesthesia personally performed by anesthesiologist | Physician anesthesiologist | 100% of allowable |
| QK | Medical direction of 2–4 concurrent CRNA/AA cases | Physician anesthesiologist (directing) | 50% of allowable (Medicare) |
| QY | Medical direction of one CRNA by one anesthesiologist | Physician anesthesiologist (directing) | 50% of allowable |
| QX | CRNA service with medical direction by physician | CRNA (medically directed) | 50% of allowable |
| QZ | CRNA service without medical direction | CRNA (independent) | 100% of allowable |
| AD | Medical supervision of 5+ concurrent procedures | Physician anesthesiologist | 3 base units + 1 time unit only |
| QS | Monitored anesthesia care (MAC) | Any provider | Standard time-based formula |
Are There Physical Status Modifiers and Qualifying Circumstances to Consider?
Physical status modifiers (P1–P6) are appended to the anesthesia code after the provider role modifier to classify patient health complexity at the time of surgery.
| Physical Status | Clinical Description | Additional Units (Commercial) | Medicare Impact |
|---|---|---|---|
| P1 | Normal healthy patient | 0 | Informational only |
| P2 | Mild systemic disease (e.g., controlled HTN) | 0 | Informational only |
| P3 | Severe systemic disease (e.g., poorly controlled DM, obesity) | +1 | Informational only |
| P4 | Life-threatening systemic disease | +2 | Informational only |
| P5 | Moribund patient; surgery as last resort | +3 | Informational only |
| P6 | Brain-dead organ donor | 0 | Not applicable |
Important: Medicare does not recognize physical status modifiers for additional payment — they are informational for that payer. Many commercial payers, however, do provide additional reimbursement for P3 and above, effectively adding units to the total claim.
Qualifying circumstance add-on codes are separately reported line items (not modifiers):
- +99100 — Patient of extreme age (under 1 year or over 70 years); adds 1 unit
- +99135 — Anesthesia complicated by controlled hypotension; adds 5 units
- +99140 — Emergency conditions; adds 2 units
Medicare does not separately reimburse qualifying circumstance codes — the values are considered bundled into base units for that payer. Most commercial payers and many Medicaid programs do pay these codes, but always verify before billing.
Are There Prior Authorization, Coverage Restrictions, or LCD Requirements?
- Medical necessity for reconstructive vs. cosmetic procedures: Payers distinguish between medically necessary reconstruction (e.g., post-mastectomy under WHCRA mandates) and purely elective cosmetic surgery. Anesthesia for cosmetic procedures may not be covered at all — confirm surgical claim approval before assuming anesthesia will be separately reimbursed.
- Women’s Health and Cancer Rights Act (WHCRA): Federal law mandates coverage for breast reconstruction after mastectomy, including anesthesia, for plans that cover mastectomy. This is relevant for cases where 00402 follows a mastectomy claim.
- No National Coverage Determination (NCD) exists specifically for CPT 00402 — coverage is determined by Local Coverage Determinations (LCDs) from each MAC and individual payer contracts.
- Prior authorization: Required by many commercial payers for elective breast reconstructive surgery; the surgical authorization typically extends to anesthesia, but confirm explicitly.
- Office-based anesthesia: Some payers impose restrictions or require separate authorization for anesthesia in non-facility settings.
What CPT Codes Are Commonly Billed Alongside CPT 00402?
Because anesthesia professionals bill separately from the surgical team, CPT 00402 appears on the anesthesia group’s claim while the surgeon bills the reconstructive surgical CPT codes on a separate CMS-1500. Understanding the surgical codes that pair with 00402 helps anesthesia coders verify crosswalk accuracy.
| Associated Surgical CPT | Procedure | Typical Pairing With 00402 | Bundling Risk |
|---|---|---|---|
| 19318 | Reduction mammoplasty | Yes — high frequency | No |
| 19325 | Augmentation mammoplasty | Yes — high frequency | No |
| 19340 | Immediate breast implant placement (same day as mastectomy) | Yes | No |
| 19342 | Delayed breast implant placement | Yes | No |
| 19357 | Tissue expander placement | Yes | No |
| 19361 | LD muscle flap reconstruction | Yes | No |
| 19364 | Free flap reconstruction (TRAM, DIEP, SIEA, GAP) | Yes — complex cases | No |
| 19350 | Nipple/areola reconstruction | Yes — staged procedures | No |
| 19370 | Revision of peri-implant capsule | Yes | No |
| 00404 | Anesthesia for radical/modified radical mastectomy | Mutually exclusive per session | Yes — report only highest BU code |
Which Code Combinations Trigger NCCI or CCI Edits?
Anesthesia codes in the 00100–01999 range have specific NCCI considerations that differ from surgical bundling rules:
- Reporting two anesthesia codes for the same operative session is incorrect. Per ASA guidelines (adopted by most payers including Medicare), when multiple surgical procedures are performed under a single anesthetic, only the anesthesia code with the highest base unit value is reported. The total time for all procedures is combined into one claim line.
- CPT 00402 cannot be stacked with 00404 or 00406 for the same patient on the same date — select the single highest-valued code.
- Surgical add-on codes for the breast procedure (e.g., 19380 revision of reconstructed breast) do not affect the anesthesia code selection — the anesthesia code covers the primary reconstructive case.
- Separately billable services not bundled into 00402 include arterial line placement (CPT 36620), central venous catheter placement (CPT 36556), and post-operative pain block injections (e.g., CPT 64415 for brachial plexus block if used for post-op analgesia). Document these as distinct services with their own rationale.
Per CMS NCCI guidelines, review Chapter 2 of the NCCI manual annually — it contains anesthesia-specific bundling guidance updated quarterly.
What Coding Errors Should You Avoid With CPT 00402?
Auditors commonly flag these patterns during claims review for anesthesia breast reconstruction procedures:
- Selecting 00402 for mastectomy procedures — The most common and consequential error. 00402 covers reconstruction. A simple total mastectomy maps to 00404. Using 00402 for a mastectomy case understates the clinical context (though base units are equal at 5, the procedural classification matters for compliance and medical necessity review).
- Omitting the required provider role modifier — Claims without AA, QK, QX, QZ, or AD are returned or denied by virtually all payers. This is a process error that delays payment and can inflate A/R aging.
- Incorrect time unit calculation — Rounding anesthesia time to the nearest 15-minute block rather than reporting actual minutes. Medicare requires actual minutes; divide by 15 to get time units. Rounding down is underpayment; rounding up is overbilling.
- Billing qualifying circumstances (99100, 99135, 99140) to Medicare — These codes are not separately reimbursable by Medicare. Submitting them to Medicare creates a coding error on the claim.
- Misidentifying the anesthesia start time — Anesthesia time begins when the provider starts preparing the patient in the OR (or equivalent), not at the surgical incision. Many EHR integrations capture “procedure start” times that differ from true anesthesia start time.
- Reporting 00402 without verifying the surgical crosswalk — If the surgeon’s operative report documents a modified radical mastectomy rather than reconstruction, the anesthesia code must step up to 00404 or 00406. Always reconcile with the surgical record before billing.
- Stacking two anesthesia procedure codes — Billing both 00402 and 00404 when both mastectomy and reconstruction occur in the same session. Report only the highest-base-unit code with the total combined time.
What Do Auditors and RAC Reviewers Look for When Reviewing CPT 00402 Claims?
Recovery Audit Contractors (RACs) and MAC pre-payment reviewers focus on:
- Mismatch between the surgical operative report and the anesthesia code — Does the documented surgery match the integumentary/reconstructive scope, or does it describe a radical procedure that belongs under 00404/00406?
- Documentation of anesthesia time — Is actual start and stop time explicitly recorded in the anesthesia record with no gaps or unexplained variance?
- Physical status modifier substantiation — Is the P-modifier supported by documentation in the pre-anesthesia assessment (e.g., P3 requires documented severe systemic disease comorbidity)?
- Medical necessity for the underlying reconstructive procedure — For post-mastectomy reconstruction cases, is the WHCRA mandate or payer authorization evident in the record?
- CRNA independence documentation — If QZ was billed (independent CRNA), is there documentation confirming no physician medical direction was established?
How Does CPT 00402 Relate to Other Anesthesia Codes?
| Related Code | Relationship Type | Key Distinction |
|---|---|---|
| 00400 | Sibling (same parent category) | Covers skin/integumentary of extremities and anterior trunk generally; less specific than 00402 |
| 00404 | Sibling (same parent category) | Radical/modified radical mastectomy without node dissection; 5 base units |
| 00406 | Sibling (same parent category) | Radical/modified radical mastectomy with internal mammary node dissection; 13 base units — highest complexity in this code family |
| 99100 | Qualifying circumstance add-on | Extreme age modifier; separately reported for patients under 1 or over 70 (non-Medicare only) |
| 99135 | Qualifying circumstance add-on | Controlled hypotension; relevant in large-volume reduction or flap cases |
| 99140 | Qualifying circumstance add-on | Emergency conditions; rarely applicable to elective reconstruction |
| 01996 | Unrelated anesthesia add-on | Daily hospital management of epidural/subarachnoid continuous drug administration; not time-based |
What Is the Correct Reporting Order When CPT 00402 Appears With Other Codes?
When multiple anesthesia and qualifying circumstance codes are involved, report in this sequence:
- Report the primary anesthesia CPT code (00402 or the highest-base-unit code if multiple procedures occurred)
- Append the provider role modifier first (AA, QK, QX, QY, QZ, or AD)
- Append the physical status modifier second (P1–P6)
- Append any CPT procedure modifiers (e.g., modifier 22 for field avoidance/extraordinary circumstances — rare but applicable)
- Report qualifying circumstance add-on codes (99100, 99135, 99140) on separate line items below the primary anesthesia code
- Report separately billable monitoring or block services (36620, 36556, 64415) as additional line items with their own modifiers, distinct from the anesthesia time claim
Real-World Coding Scenario — How CPT 00402 Is Applied in Practice
Clinical scenario: A 52-year-old woman with a history of breast cancer presents for delayed left breast reconstruction approximately 14 months after a modified radical mastectomy. The surgeon performs a pedicled latissimus dorsi (LD) muscle flap reconstruction with placement of a tissue expander (CPT 19361). Anesthesia is provided by a physician anesthesiologist personally performing the case, total anesthesia time is 155 minutes. The patient has well-controlled hypertension (physical status P2). No emergency or qualifying age criteria apply.
Correct Code Application
- Anesthesia CPT: 00402 (reconstructive procedure on breast — LD flap maps via ASA Crosswalk® from surgical CPT 19361)
- Modifier stack: AA (personally performed by anesthesiologist), P2 (mild systemic disease — controlled HTN)
- Full claim line: 00402-AA-P2
- Time units: 155 ÷ 15 = 10.33 time units
- Total billable units: 5 (base) + 10.33 (time) = 15.33 units
- Medicare estimated payment: 15.33 × ~$21.56 = approximately $330.51
Common Mistake in This Scenario
- Incorrect code selected: 00404 (anesthesia for radical/modified radical procedures on breast)
- Why it fails: The patient’s current procedure is reconstruction (19361), not a mastectomy. The prior mastectomy happened 14 months ago under a separate anesthesia claim. Selecting 00404 today misrepresents the surgical procedure being anesthetized, creating a mismatch between the surgical and anesthesia claims and potential audit exposure.
- Second common error: If a P3 modifier were incorrectly applied (no documentation of severe systemic disease), commercial payers might pay an extra base unit that cannot be supported on audit, creating an overpayment liability.
Frequently Asked Questions About CPT Code 00402
Is CPT Code 00402 Still Valid for Use in 2026?
CPT 00402 remains a valid, actively billable anesthesia code as of 2026, with its descriptor updated effective January 1, 2026 per the AAPC/FindACode update record. Coders should verify annually against the AMA CPT Professional Edition and the CMS Physician Fee Schedule to confirm no descriptor or base unit changes have been implemented for the current plan year.
What Is the Difference Between CPT 00402 and CPT 00404?
CPT 00402 covers anesthesia for reconstructive breast procedures — augmentation, reduction, flap surgery, and implant placement — while CPT 00404 is used for radical or modified radical mastectomy procedures. Both codes carry 5 base units, but they describe fundamentally different surgical events; using them interchangeably creates a crosswalk mismatch and can trigger a medical records request or claim denial on audit.
How Many Base Units Does CPT 00402 Have?
CPT 00402 is assigned 5 base units by the ASA Relative Value Guide, as listed in the CMS Table H (Professional Anesthesia Nationwide Base Units). These base units represent the inherent complexity of the procedure and do not change with anesthesia duration — only time units vary based on the actual length of the case.
Does Medicare Pay for Qualifying Circumstance Codes (99100, 99135, 99140) With CPT 00402?
Medicare does not separately reimburse qualifying circumstance add-on codes (99100, 99116, 99135, or 99140) when billed alongside CPT 00402 or any other anesthesia code. CMS considers their value to be bundled into the base unit value. Most commercial payers and some state Medicaid programs do recognize these codes for additional payment — always verify individual payer policy before reporting them.
What Happens When Both Mastectomy and Reconstruction Occur in the Same Operative Session?
When both mastectomy and reconstruction are performed under a single anesthetic (e.g., immediate implant placement on the same day as mastectomy), the ASA rule and most payer policies require reporting only one anesthesia code — the one with the highest base unit value — for the combined case. If the mastectomy code (00404, 5 BU) and reconstruction code (00402, 5 BU) are equal, report either; use the one that best characterizes the primary surgical intent. Total anesthesia time for both procedures is combined into a single time calculation.
Can a CRNA Bill CPT 00402 Independently?
A CRNA may bill CPT 00402 independently and report it with modifier QZ (CRNA without medical direction) to receive 100% of the allowable rate. If the CRNA is medically directed by a supervising anesthesiologist who meets all seven CMS medical direction criteria, the CRNA reports modifier QX and the physician reports modifier QK (or QY for single-case direction), each at 50% of the allowable. Failure to correctly identify the supervision relationship is one of the most frequently cited anesthesia billing compliance issues per OIG audit guidance.
What Is the ASA Crosswalk® and Why Does It Matter for CPT 00402?
The ASA Crosswalk® (published in the ASA Relative Value Guide) is the tool anesthesia coders use to map a surgical CPT code to its corresponding anesthesia CPT code. Because the surgical team and the anesthesia team file separate claims with different procedure codes, the Crosswalk® ensures the anesthesia code accurately reflects the surgical procedure performed. For breast reconstruction, surgical codes like 19318, 19357, and 19361 map to 00402. Bypassing the Crosswalk® and guessing at the anesthesia code is a leading cause of crosswalk mismatches and compliance risk.
Key Takeaways for Billing and Coding CPT 00402
- CPT 00402 applies to reconstructive breast procedures only — augmentation, reduction, flap reconstruction, and implant placement. It does not apply to radical mastectomy (use 00404 or 00406).
- The code carries 5 ASA base units; payment is driven by the combined total of base units and time units multiplied by a payer-specific conversion factor.
- Every claim for 00402 requires a provider role modifier (AA, QK, QX, QY, QZ, or AD) — omitting it causes claim rejection.
- Physical status modifiers (P1–P6) are informational for Medicare but can generate additional reimbursement from commercial payers for P3 and above.
- Qualifying circumstance add-on codes (99100, 99135, 99140) are not separately reimbursable by Medicare but may be billable to commercial payers — verify before reporting.
- When multiple breast procedures (e.g., mastectomy + immediate reconstruction) occur under a single anesthetic, report only the highest-base-unit anesthesia code with total combined time.
- Always verify the ASA Crosswalk® match between the surgical CPT and the anesthesia CPT before finalizing the claim, and reconcile anesthesia records with the operative report to prevent crosswalk mismatches during audit.
For additional revenue cycle compliance guidance on anesthesia coding, refer to the CMS Medicare Claims Processing Manual, Chapter 12 and the ASA Relative Value Guide published annually by the American Society of Anesthesiologists.
