CPT Code 01340: Anesthesia for closed distal femur procedures

Key Takeaways

CPT Code 01340 covers anesthesia for all closed (non-surgical) procedures on the lower one-third of the femur only — it does not cover the knee joint, the popliteal area, or any open or arthroscopic surgery.

The code carries 4 anesthesia base units per the ASA Relative Value Guide, which forms the starting point for reimbursement calculations.

Reimbursement is calculated as (Base Units + Time Units) x Conversion Factor; missing time-unit documentation is the leading cause of 01340 claim denials.

Practice management software like Pabau helps anesthesia and surgical billing teams track and manage claims from submission through payment, cutting down the manual work behind chasing denials.

CPT Code 01340 is an anesthesia code for closed, non-surgical treatment of the lower one-third of the femur, such as closed reduction of a distal femur fracture. It excludes the knee joint, the popliteal area, and any open or arthroscopic procedure.

CPT Code 01340: Definition and anatomical scope

CPT Code 01340 has the following official AMA description: Anesthesia for all closed (non-surgical) procedures on the lower one-third of the femur.

“Closed” is the operative word: the code applies only when the fracture or bone segment is treated without a surgical incision, such as closed reduction or closed manipulation of the distal femur. It does not extend to the knee joint, the popliteal area, or any open or arthroscopic surgical procedure.

The lower one-third of the femur is the distal segment of the thigh bone, just above the knee joint — the region involved in supracondylar, transcondylar, and distal shaft fractures.

CPT 01340 covers anesthesia for closed treatment in that region only: closed reduction, closed manipulation, or the application of traction, all without opening the fracture site.

As soon as a surgeon opens the fracture (an ORIF, for example) or the procedure involves the knee joint itself, a different code in the same anesthesia series applies. See the comparison table further down this page.

Procedures covered under CPT Code 01340

The word “closed” in the AMA descriptor is the key restriction. CPT Code 01340 applies only to anesthesia for non-surgical treatment of the distal femur — procedures where the fracture is reduced or manipulated without opening the surgical site.

These procedures show up more often in orthopedic trauma and emergency settings than in elective practice, though sports medicine practices treating acute fractures bill it too.

• Closed treatment of femoral shaft fracture, with manipulation – CPT 27502; may include skin or skeletal traction
• Closed treatment of femoral shaft fracture, without manipulation – CPT 27500
• Closed treatment of supracondylar or transcondylar femoral fracture, with manipulation – CPT 27503; the most common pairing with 01340
• Closed treatment of supracondylar or transcondylar femoral fracture, without manipulation – CPT 27501
• Closed treatment of distal femoral fracture (medial or lateral condyle), with manipulation – CPT 27510
• Closed treatment of distal femoral fracture (medial or lateral condyle), without manipulation – CPT 27508
• Closed treatment of distal femoral epiphyseal separation, with manipulation – CPT 27517; typical for Salter-Harris Type II fractures in pediatric patients
• Closed treatment of distal femoral epiphyseal separation, without manipulation – CPT 27516; typical for Salter-Harris Type I fractures

The underlying surgical CPT code is billed by the operating surgeon. The anesthesiologist or CRNA bills CPT Code 01340 separately on their own claim. These are distinct, non-conflicting lines.

Anesthesia base units for CPT Code 01340

CPT 01340 carries 4 anesthesia base units as assigned by the American Society of Anesthesiologists (ASA) Relative Value Guide (RVG). Base units represent the complexity and risk associated with the anatomical site and typical procedures, independent of time spent.

For context, higher-complexity anesthesia codes (such as cardiac or thoracic procedures) carry base units ranging from 8 to 25. A base unit value of 4 reflects the moderate complexity of closed fracture management, which typically takes less time and carries lower risk than open surgery on the same anatomical region.

The base unit is the fixed starting value in every reimbursement calculation for this code.

How anesthesia reimbursement is calculated for CPT Code 01340

The Medicare anesthesia payment formula is: (Base Units + Time Units) x Conversion Factor = Reimbursement. Each component is defined precisely, and errors in any one of them cause underpayment or denial.

Time units are calculated by dividing total anesthesia time (in minutes) by 15. One time unit equals 15 minutes of anesthesia time under standard Medicare billing rules, per the CMS Physician Fee Schedule. Some commercial payers use different intervals (10-minute or 12-minute units); confirm with each payer before submitting.

The conversion factor varies by Medicare Administrative Contractor (MAC) locality. A practice in Manhattan will receive a higher locality-adjusted rate than one in rural Mississippi.

Always verify the current-year conversion factor and geographic adjustment factor (GAF) through the AMA’s CPT coding resources or your MAC’s published fee schedule.

Medicare fee schedule and reimbursement rates for CPT Code 01340

Medicare reimbursement for CPT Code 01340 is not a flat published rate. It is calculated using the formula above, with the conversion factor varying by locality and updated annually. The national base Medicare anesthesia conversion factor for 2026 is $20.4976 per anesthesia unit, subject to geographic adjustment.

CPT 01340 fee schedule by payer

Commercial payers set their own conversion factors and base unit values, which frequently differ from Medicare. Some payers accept the ASA RVG base unit of 4; others have proprietary relative value schedules.

For current Medicare locality rates, enter code 01340 into the CMS Physician Fee Schedule lookup tool and select the applicable MAC jurisdiction to retrieve the locality-specific conversion factor and anesthesia rate.

Modifiers used with CPT Code 01340

Anesthesia modifier selection is not optional. Medicare and most commercial payers require a modifier on every anesthesia claim to indicate who performed the service and under what supervision arrangement. Missing or incorrect modifiers are among the top denial triggers for CPT 01340 claims.

When modifier AA is billed, the anesthesiologist receives 100% of the allowable. QK paired with QX splits reimbursement: the directing physician receives 50% and the CRNA receives 50%. These split-billing rules apply to Medicare; commercial payer policies vary.

Physical status modifiers (P1-P6)

Physical status modifiers describe patient health status at the time of anesthesia. They are appended after the provider modifier on anesthesia claims. Medicare does not pay additional amounts for physical status modifiers P1 through P6. Some commercial payers do assign incremental base unit adders, typically +1 for P3, +2 for P4, and +3 for P5.

CRNA and medical direction billing for CPT Code 01340

CRNAs may independently bill CPT Code 01340 under Medicare when functioning without physician medical direction. In those cases, modifier QZ is appended and the CRNA receives 100% of the Medicare allowable.

This applies in states that have opted out of the federal physician supervision requirement, as well as in states where the opt-out has not occurred but the CRNA is practicing within state scope laws.

When a physician anesthesiologist directs a CRNA, both providers submit separate claims with complementary modifiers: the directing physician uses QK (or QY for a single CRNA), and the CRNA uses QX. Each receives 50% of the Medicare allowable.

Practices that also offer physical therapy services for post-fracture rehab need these billing splits documented clearly across both specialties.

Medical direction requires the anesthesiologist to fulfill seven specific CMS requirements during the procedure (including pre-anesthesia evaluation, being present at induction, monitoring at critical moments, and being immediately available throughout).

Failure to document any of these steps converts the claim from medical direction (QK/QX) to medical supervision (AD), which pays significantly less.

ICD-10 diagnosis codes commonly linked to CPT Code 01340

Every CPT Code 01340 claim must be supported by an ICD-10-CM diagnosis code that establishes medical necessity. The diagnosis code is billed on the surgical claim by the operating physician; the anesthesia claim should reflect the same primary diagnosis, such as S72.91XH for unspecified femur fractures.

Always confirm ICD-10 laterality (right vs. left) matches the operative report. A right-leg procedure billed with a left-leg diagnosis code is a common data-entry denial that delays payment by 30 to 60 days. The same laterality risk applies to adjacent lower-extremity fractures, such as S82.61XN.

Related CPT codes in the anesthesia series

CPT Code 01340 belongs to the 01000-01999 anesthesia series, organized by anatomical site. Codes that sit closest to 01340 in the CPT manual cover very different scopes: the knee joint, the popliteal soft tissue, the upper femur, or the same femur segment treated with open surgery instead of closed.

The upper femur has its own code, 01220, and it’s easy to confuse with 01340 when a fracture spans both segments.

The distinction between 01340 and 01360 is the one billing teams most often get wrong. Both apply to the lower one-third of the femur, but 01340 is for closed (non-surgical) treatment and 01360 is for open surgical treatment of the same anatomical segment.

If the operative report describes an incision, hardware placement, or an open reduction, the case belongs under 01360 or a knee-specific code, not 01340. Verify with the operative report before selecting any code in this table.

Documentation and medical necessity requirements for CPT Code 01340

Anesthesia records must contain enough detail to support both the CPT Code 01340 selection and the reimbursement calculation. Auditors and payers look for specific data points that many anesthesia teams record in the OR but fail to transfer accurately to the billing claim.

For a broader overview of HIPAA compliance for medical offices, including documentation retention requirements, see Pabau’s compliance guide.

• Anesthesia start and stop times – exact times (not estimated ranges); this is the basis for all time-unit calculations
• Procedure performed – surgical CPT code and anatomical site must match the selected anesthesia code
• Provider credentials and role – document whether services were provided by an MD/DO, CRNA, or AA, and the supervision arrangement
• Pre-anesthesia evaluation – documented history and physical, ASA physical status classification, and anesthesia plan
• Intraoperative monitoring records – vital signs, airway management, drugs administered
• Post-anesthesia care notes – recovery phase documentation confirming safe patient handoff
• Medical direction checklist – all seven CMS criteria, each time-stamped, when QK or QY modifier is used

The AAPC and CMS both emphasize that anesthesia time must be documented continuously from the moment the anesthesia provider begins preparing the patient for induction through the moment the provider is no longer present in personal attendance.

Rounding time to the nearest procedure block (for example, always billing 45 minutes for a closed reduction without chart support) is a compliance risk that can trigger recoupment on audit. For reference, see AAPC’s CPT code lookup and coding guidelines.

Common billing errors and denial reasons for CPT Code 01340

Claim denials for CPT Code 01340 cluster around a predictable set of errors. Most are preventable with a pre-submission billing checklist. Practices that use claims management software to track and review claims before submission catch the majority of these issues before the claim leaves the system.

• Missing provider modifier – submitting 01340 without AA, QZ, QK, or QY causes automatic rejection on Medicare claims
• Wrong time units – transcription errors converting minutes to units (e.g., billing 6 units for 45 minutes instead of 3) are among the most common arithmetic errors in anesthesia billing
• ICD-10 laterality mismatch – right femur surgical code paired with a left femur diagnosis; resolved by cross-checking the operative report before submission
• Incorrect code selection – billing 01340 for a procedure that turns out to be open surgery, knee-joint work, or a total knee arthroplasty; each of those belongs under a different code (01360, 01380/01400, or 01402)
• QK/QX without medical direction documentation – the medical direction criteria (7 CMS requirements) are not documented in the anesthesia record; claim downcodes to AD rates
• Physical status modifier mismatch – appending P4 or P5 on a Medicare claim expecting a unit adder; Medicare does not pay P modifier adders
• Duplicate billing – when both the anesthesiologist and CRNA bill under QK/QX for the same procedure without complementary modifiers; triggers coordination of benefits review
• Time reporting inconsistency – anesthesia start time in the record differs from the time on the claim form

Documentation requirements are similar for other femur anesthesia codes, including 01234 for radical femur resection. Additional CPT and ICD-10 coding resources are available through the CMS ICD-10 codes page.

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Billing CPT Code 01340 correctly

CPT Code 01340 covers a narrower scope than its neighbors in the CPT manual: closed, non-surgical treatment of the lower one-third of the femur, and nothing beyond that. The four-base-unit value is fixed.

The reimbursement, however, depends on selecting the right code in the first place, plus accurate time documentation, correct modifier selection, and ICD-10 laterality that matches the operative record. Each of those touchpoints is a potential denial.

Practice management software like Pabau helps anesthesia and surgical billing teams track, submit, and monitor claims from a single system. To see how it handles anesthesia billing for orthopedic and surgical practices, book a demo.

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