CPT code 01464: Anesthesia for ankle and foot arthroscopy

Key Takeaways

CPT code 01464 describes anesthesia for arthroscopic procedures of the ankle and/or foot — distinct from CPT 01400, the separate knee-joint arthroscopy code it is sometimes confused with

The code carries 3 base units; reimbursement is calculated as (Base Units + Time Units + Modifying Units) x Conversion Factor

Modifier selection (AA, QK, QX, QZ) depends on whether an anesthesiologist performs or medically directs the case, and whether a CRNA is involved

Pabau’s claims management software streamlines CPT 01464 billing by combining code entry, modifier selection, and claim submission in one workflow

CPT code 01464: Definition and clinical overview

Anesthesia billing denials for lower-limb procedures often trace back to one root cause: the wrong code selection between adjacent, similarly numbered anesthesia codes. CPT code 01464 is the specific code for arthroscopic procedures of the ankle and/or foot. It is not interchangeable with neighboring lower-leg codes like 01462 or 01470, and — importantly — it is a different code entirely from CPT 01400, which covers arthroscopic procedures on the knee joint.

Getting this code wrong triggers claim rejections, delayed reimbursement, and audit flags. This reference covers the official description, base unit value, applicable modifiers, 2025/2026 Medicare reimbursement rates, common ICD-10 pairings, and billing guidelines for CPT code 01464 so anesthesia billers and coders can submit clean claims the first time.

CPT code 01464 covers anesthesia for arthroscopic procedures performed on the ankle joint and/or the foot, including diagnosis and treatment of osteochondral lesions, anterior ankle impingement, loose bodies, synovitis, and chronic ankle instability. It sits in the “Anesthesia for Procedures on the Lower Leg (Below Knee)” section of the CPT anesthesia code set, alongside 01462, 01470, and 01480 — all of which also cover the lower leg, ankle, and foot region. It does not cover knee-joint arthroscopy, which is billed under the separate code CPT 01400 in the distinct “Knee and Popliteal Area” section.

Base units for CPT 01464 and the reimbursement formula

CPT code 01464 carries 3 base units, set by the American Medical Association and confirmed on CMS and VA nationwide anesthesia base-unit tables. Base units represent the inherent complexity of administering anesthesia for a given procedure type. Every anesthesia reimbursement calculation for this code starts here.

The standard Medicare anesthesia reimbursement formula is:

Time units are calculated by dividing total anesthesia time (start of induction to patient transfer out of anesthesia care) by 15 minutes, rounding to the nearest unit per payer policy. Accurate time documentation is therefore critical: a 60-minute case generates 4 time units, giving a total of 7 units before modifying units. You can verify current conversion factor values using the CMS Physician Fee Schedule lookup tool.

Modifiers for CPT code 01464

Modifier selection for CPT code 01464 determines how much Medicare reimburses and who is authorized to bill. The wrong modifier on an anesthesia claim is one of the fastest routes to a denial or a post-payment audit.

For medical direction (QK/QX) to be valid under CMS rules, the anesthesiologist must satisfy all seven conditions: performing the pre-anesthesia evaluation, prescribing the plan, personally participating in the most demanding portions, remaining available throughout, providing post-anesthesia care, not concurrently directing more than four cases, and not performing other services during that time. Missing a single condition voids the medical direction claim and exposes the practice to repayment liability.

CRNA eligibility for QZ billing varies by state. As of mid-2026, 26 states have opted out of the federal physician supervision requirement, allowing CRNAs to bill at the full rate independently. Confirm your state’s current opt-out status using the ASA opt-out tracker before applying QZ to any CPT code 01464 claim. More on billing compliance protocols is available for practices building internal review processes.

Reimbursement and fee schedule for CPT code 01464

Medicare calculates anesthesia reimbursement using the formula described above, applying a locality-specific conversion factor. The Centers for Medicare and Medicaid Services (CMS) publishes an annual anesthesia conversion factor; the rate varies by geographic practice cost index (GPCI) locality, meaning a practice in San Francisco reimburses differently from one in rural Mississippi for the identical CPT code 01464 claim.

Medicare reimbursement calculation example

A 45-minute ankle arthroscopy under general anesthesia billed with CPT code 01464 generates 3 time units (45 minutes divided by 15). With 3 base units, a P1 patient (0 modifying units), and an illustrative conversion factor of $21.00, the calculation is: (3 + 3 + 0) x $21.00 = $126.00 for an AA modifier claim. QK and QX claims at 50% would each receive $63.00. Verify current conversion factor values directly via the FastRVU 2026 RVU lookup tool or on the CMS fee schedule for the applicable payment year.

Private payer rates are negotiated separately and often exceed Medicare rates. Medicaid rates vary by state and typically fall below Medicare. When billing CPT code 01464 to commercial insurers, confirm the payer’s specific conversion factor and any policy-level modifiers in the provider contract before submitting.

ICD-10 codes commonly paired with CPT 01464

Every CPT code 01464 claim must carry at least one ICD-10-CM diagnosis code establishing medical necessity. The diagnosis must support the arthroscopic procedure being performed on the ankle or foot. Mismatched or overly vague diagnosis codes are a top reason for claim rejections on anesthesia services.

Always verify ICD-10-CM codes against the current tabular list before submission. Using the AAPC Codify CPT lookup alongside the ICD-10 crosswalk can confirm medical necessity linkage. Laterality matters: codes for left-side and right-side ankle and foot procedures are distinct, and submitting without the correct laterality qualifier commonly triggers edits.

Billing guidelines for CPT code 01464

Clean CPT code 01464 claims require meeting several pre-submission checkpoints. Skipping any one of them increases the likelihood of a rejection or a post-payment audit. Review these medical office compliance requirements alongside the code-specific rules below.

• Provider eligibility: The billing provider must be a licensed anesthesiologist or CRNA. The appropriate billing modifier (AA, QK, QX, QZ, QY, AD) must match the documented provider role for the case.
• Code specificity: CPT code 01464 applies only to arthroscopic procedures of the ankle and/or foot. Procedures on other lower-leg sites, or on the knee joint (CPT 01400), require different codes (see Related CPT codes below).
• Time documentation: Start and stop times for anesthesia must be recorded in the anesthesia record. Some payers require start and stop times to be documented in 15-minute increments; others accept total elapsed time.
• Medical necessity linkage: ICD-10-CM diagnosis codes must directly support the procedure. Unspecified or non-specific diagnoses without supporting documentation will fail payer review.
• Medical direction conditions: When using QK or QX, all seven CMS medical direction conditions must be documented in the record. One missing condition voids the claim.
• Physical status modifier: Append the appropriate P-modifier (P1 through P6) to reflect the patient’s physical status. P1 carries no additional units; P3 adds 1 unit, P4 adds 2 units, and P5 adds 3 units per standard ASA convention.

Documentation requirements

Anesthesia records for CPT code 01464 must contain all of the following to support audit-proof billing. Using standardized clinical documentation forms reduces the risk of missing a required element.

• Pre-anesthesia evaluation: Documented history, physical examination, ASA physical status classification, and anesthesia plan (required for AA and all medical-direction scenarios)
• Intraoperative anesthesia record: Continuous vital sign monitoring, anesthetic agents administered, time of induction, duration of anesthesia, and provider identity
• Anesthesia start and stop times: Exact timestamps for when anesthesia was induced and when the patient was transferred out of anesthesia care
• Provider credentials: Documentation confirming the billing provider’s license type (MD/DO anesthesiologist or CRNA) and, where applicable, the supervising anesthesiologist’s identity and attestation
• Post-anesthesia note: Assessment of the patient’s status in the recovery area, including any complications noted during or after the procedure
• Consent: Signed informed consent for anesthesia, separate from the surgical consent

Maintaining HIPAA-compliant documentation practices across all anesthesia records protects the practice both during payer audits and in the event of a patient complaint. Digital anesthesia records also support faster retrieval during post-payment review windows. Consider moving to paperless anesthesia record workflows to streamline this process.

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Related CPT codes for lower leg, ankle, and foot anesthesia

Coders frequently look up CPT code 01464 alongside adjacent lower-leg anesthesia codes — and alongside CPT 01400, the separate knee-joint arthroscopy code it’s sometimes confused with. The distinctions are specific: wrong code selection between 01462, 01464, and 01400 is a common billing error because all three involve arthroscopic or lower-limb anesthesia. You can also compare other CPT code references and procedure-specific CPT codes on Pabau’s procedure code library.

The critical distinction for CPT code 01464 is twofold. First, versus 01400: 01464 applies to the ankle and/or foot, while 01400 applies to the knee joint — different anatomical sites, different CPT sections, and different base unit values (3 versus 4), so the two are never interchangeable. Second, versus 01462, 01470, and 01480: all four ankle/foot-region codes share the same 3 base units, so payers rely entirely on procedure type (arthroscopic, closed, soft tissue, or open bone) to differentiate the claim. Billing an ankle arthroscopy under 01462, or a knee arthroscopy under 01464, will likely trigger a denial for a procedure-code mismatch.

How practice management software supports anesthesia billing

Reference tools and fee schedule lookups tell you what CPT code 01464 pays. Getting it paid accurately requires clean execution across every step of the claim lifecycle: code selection, modifier assignment, documentation capture, and submission. Most anesthesia billing errors do not happen because coders do not know the rules; they happen because the workflow breaks down between the anesthesia record, the billing team, and the clearinghouse.

Practice management platforms that integrate clinical documentation with billing workflows reduce that gap. Pabau’s claims management workflows allow billing teams to enter CPT codes, apply modifiers, attach supporting diagnosis codes, and submit claims within a single platform rather than switching between a coding reference tool, an EHR, and a separate billing system. The digital intake and documentation forms feature supports structured pre-anesthesia evaluations and intraoperative records that can be retrieved quickly during payer audit requests.

For practices running multiple anesthesia providers across different case types, automated billing workflows can trigger documentation reminders at case completion, flag missing time entries before claims are batched, and route claims by modifier type for team review. Practice management software that connects the clinical record to the billing cycle is where most anesthesia practices find meaningful reductions in denial rates.

Conclusion

CPT code 01464 is a precise code: it applies specifically to arthroscopic procedures of the ankle and/or foot, carries 3 base units, and reimburses differently depending on which modifier reflects the documented provider role. It is a distinct code from CPT 01400 (knee joint arthroscopy, 4 base units) and from its lower-leg neighbors 01462, 01470, and 01480 (each also 3 base units, but for different procedure types). The most common billing failures on this code come from three sources: incorrect modifier selection for the care arrangement, missing or incomplete documentation of medical direction conditions, and mismatched ICD-10-CM diagnosis codes.

Pabau’s claims management software helps anesthesia and surgical practices close those gaps by connecting clinical documentation to claim submission in one workflow. To see how it handles anesthesia code billing in practice, book a demo with the team.

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Frequently asked questions