CPT code 01200: Anesthesia for hip joint procedures 2026

Key Takeaways

CPT code 01200 covers anesthesia for all closed procedures involving the hip joint, as defined by the AMA CPT code set.

The code carries 4 base units per the ASA Relative Value Guide; reimbursement uses the formula (Base Units + Time Units + Modifying Units) x Conversion Factor.

Modifiers AA, QK, QX, and QZ apply depending on provider type; selecting the wrong modifier is one of the most common claim denial triggers for CPT 01200.

Pabau’s claims management software helps anesthesia practices track CPT codes, document start and stop times, and reconcile reimbursements against expected anesthesia rates.

CPT code 01200 is defined by the American Medical Association as: Anesthesia for all closed procedures involving the hip joint. “Closed” means the joint capsule is not opened during the procedure. In practice, the code applies to anesthesiologists and Certified Registered Nurse Anesthetists (CRNAs) providing general, regional, or monitored anesthesia care for qualifying hip procedures.

Common procedures coded under 01200 include closed reduction of a dislocated hip, hip fracture reduction, and manipulation under anesthesia for hip joint contracture — procedures typically performed by orthopedic surgeons and sports medicine practices. However, open hip procedures, hip scope (arthroscopy), and femoral shaft work fall outside this code’s scope and require codes from elsewhere in the 01200-01274 range.

Base units and the reimbursement formula for CPT code 01200

CPT code 01200 carries 4 base units as assigned by the American Society of Anesthesiologists (ASA) Relative Value Guide. In other words, base units reflect the complexity and risk of the anesthetic case independent of time.

Closed hip procedures rate lower than their open counterparts because the joint capsule is never entered, which reduces surgical time, blood loss risk, and the physical demands placed on the anesthesia team compared with an open approach.

Anesthesia reimbursement does not use a flat fee. Instead, the formula, set out in the CMS Physician Fee Schedule, combines three variables:

• Base units (B): fixed at 4 for CPT 01200 per the ASA RVG
• Time units (T): 1 unit per 15 minutes of anesthesia time (most payers; some use different intervals)
• Modifying units (M): qualifying circumstance add-on codes (see section below)

The calculation: (B + T + M) × Conversion Factor (CF). The CF is locality-specific and changes annually. For 2026, Medicare conversion factors vary by geographic area; therefore, verify the current rate for your locality using the CMS Physician Fee Schedule lookup tool.

Worked example: A hip fracture reduction under CPT 01200 lasting 90 minutes. Base units = 4. Time units = 90 / 15 = 6. No qualifying circumstances. Total = 10 units × locality CF = reimbursement. As a result, at a sample CF of $22.00 (example only; actual rates vary), that yields $220 before modifiers and payer contract adjustments.

Time unit documentation

Time units depend directly on documented start and stop times. In addition, CMS requires the anesthesia record to show the exact minute anesthesia was induced (start) and the minute the patient was transferred to post-anesthesia care (stop). Rounding to the nearest quarter-hour after the fact is not acceptable and is a primary audit trigger. Automated clinical documentation tools that capture real-time timestamps greatly reduce this exposure.

Medicare fee schedule and 2026 conversion factor context

Medicare does not publish a single national rate for CPT code 01200. Instead, reimbursement is set by multiplying total anesthesia units by the locality-specific Medicare Anesthesia Conversion Factor (ACF). For 2026, the ACF varies by MAC jurisdiction. Because of this, practices billing Medicare for CPT 01200 should pull their locality’s ACF from the CMS Physician Fee Schedule lookup each January when rates reset.

Commercial payer rates for CPT 01200 are worked out separately and typically exceed Medicare rates. Some payers contract on a per-unit basis using a different CF; others carve anesthesia into a flat case rate. However, verify your contract terms before assuming the Medicare formula applies to all payers.

For anesthesia practices managing reimbursement tracking across payers, practice management software that combines billing with payment matching helps surface shortfalls against expected rates per the contracted CF.

Anesthesia modifiers for CPT code 01200

Modifier selection decides which provider type is being billed and directly affects reimbursement percentage. As a result, choosing the wrong modifier on CPT code 01200 is the single most common cause of claim denial and post-payment audit exposure. The AMA coding resources and CMS Medicare Claims Processing Manual Chapter 12 govern these rules.

Requirements for billing modifier QK

Medical direction under QK requires the anesthesiologist to meet seven specific conditions for each concurrent case, per the Medicare Claims Processing Manual (Pub. 100-04, Ch. 12, §50):

• Perform the pre-anesthesia exam and evaluation
• Prescribe the anesthesia plan
• Personally participate in the most demanding procedures, including induction and emergence
• Ensure any procedures not personally performed are done by a qualified individual
• Monitor the course of anesthesia at frequent intervals
• Remain physically present and available for immediate diagnosis and treatment of emergencies
• Provide indicated post-anesthesia care

In addition, a separate rule caps medical direction at four concurrent cases. Exceeding that limit converts the claim to supervision under modifier AD rather than medical direction. Failure to document any one of the seven conditions above converts a QK claim to an unallowable supervision claim.

Qualifying circumstances add-on codes for CPT code 01200

Qualifying circumstances codes may be billed alongside CPT code 01200 when the clinical situation adds complexity beyond the base procedure. However, each code has specific clinical criteria; billing without meeting them is a compliance risk under the National Correct Coding Initiative (NCCI).

Code 99100 is frequently applicable to hip fracture cases, which disproportionately affect patients over 70. Similarly, code 99140 applies to emergent hip fracture repairs where delay would worsen outcome. Therefore, both require documented clinical justification in the anesthesia record. Supporting this with digital clinical forms that capture patient age, emergency status, and provider sign-off reduces audit exposure.

Similarly, the same qualifying-circumstance logic applies to other anesthesia procedures: 01962, anesthesia for urgent postpartum hysterectomy, uses its own add-on codes tied to comparable emergency criteria.

ICD-10 diagnosis codes used with CPT code 01200

Every CPT 01200 claim requires a linked ICD-10-CM diagnosis code establishing medical necessity. The most common pairings, verified against current CDC/NCHS ICD-10-CM classifications, are listed below. These codes are valid for FY 2026; therefore, verify annually as ICD-10-CM updates each October 1.

Use the most specific laterality code available. In addition, bilateral hip procedures on the same date require separate line items with modifiers 50, LT, and RT as appropriate. The same level-of-detail principle applies across orthopedic ICD-10 coding generally: as with M15.9, an unspecified code invites a medical necessity denial where a more specific one would clear.

Patients recovering from hip fracture reduction or manipulation under anesthesia typically move into physical therapy within days of discharge. As a result, practices that also run physical therapy EMR software can track functional recovery milestones against the same patient record used for the anesthesia and surgical documentation, instead of starting a new chart in a separate system.

Related anesthesia CPT codes in the 01200-01274 range

CPT code 01200 is one of 15 codes covering anesthesia for the hip and upper leg. Selecting the wrong sibling code, particularly confusing closed hip procedures with open or hip scope cases, is a common unbundling error. Therefore, the AAPC CPT code lookup can help confirm descriptions when the operative note is ambiguous about technique.

Note that total hip arthroplasty performed as an open procedure uses 01214 (8 base units), not 01200. For example, this distinction is frequently missed when the operative note describes the procedure generically as “hip replacement.” Therefore, review the technique description, not just the procedure name, before coding.

Similarly, sibling-code distinctions apply in ADHD screening CPT codes and coaching CPT codes, where adjacent codes share surface-level descriptions but carry different billing rules.

Documentation requirements for CPT 01200 claims

CMS Medicare Claims Processing Manual Chapter 12 specifies that anesthesia claims must be supported by a complete anesthesia record. In fact, missing documentation is the second most common denial driver after modifier errors. Pabau’s compliance management tools support structured capture of the required elements across outpatient and inpatient settings.

• Pre-anesthesia evaluation: documented assessment of the patient’s physical status, airway, relevant history, and planned anesthetic technique, completed before the procedure begins
• Intraoperative anesthesia record: continuous record of vital signs, drug administration, and provider attestation at defined intervals
• Start and stop times: exact minute-level timestamps for when anesthesia was induced and when the patient was transferred to PACU; required for time unit calculation
• Provider credentials: the record must identify whether an anesthesiologist, CRNA, or both provided care, supporting the modifier billed
• Post-anesthesia note: a note documenting the patient’s status at discharge from anesthesia care, typically the same day as the procedure
• Qualifying circumstance justification: if 99100, 99116, 99135, or 99140 are billed, the chart must document the clinical basis (patient age, emergency status, total body hypothermia, or controlled hypotension)

For practices managing anesthesia documentation across multiple surgical locations, multi-location management tools help standardize record capture so the same compliance criteria are met at every site. Similarly, the same principle holds across specialties: clinical documentation software that prompts for the required fields at the point of care is what actually decides whether a claim is billable.

Common billing errors and denial reasons for CPT code 01200

Anesthesia claims for CPT code 01200 are denied more often than most surgical anesthesia codes because the modifier rules and time documentation requirements interact with payer-specific policies in unpredictable ways. As a result, the errors below account for the majority of avoidable denials, according to patterns documented in CMS anesthesia billing guidance and NCCI policy.

• Wrong modifier: billing AA when QK/QX applies (or QZ when medical direction was provided) is the most-audited error; it triggers both denial and potential False Claims Act exposure
• Missing time documentation: submitting claims without start/stop times, or with times rounded to the hour rather than the exact minute
• Confusing hypothermia and hypotension codes: billing 99135 (controlled hypotension) when the anesthesia record documents total body hypothermia instead, which is billed as 99116
• Wrong code for open THA: coding 01200 (closed, 4 base units) for a case that used an open approach requiring 01214 (8 base units)
• Missing ICD-10 laterality: submitting M16.1 instead of M16.11 (right) or M16.12 (left), triggering medical necessity edit failures
• Billing qualifying circumstances without clinical justification: adding 99100 for a 72-year-old without documenting age in the anesthesia record

Ultimately, systematic billing error prevention is easier when clinical documentation, coding, and HIPAA-compliant record management are handled within a single platform rather than across disconnected tools.

How Pabau supports anesthesia billing workflows

Anesthesia billing requires a tighter feedback loop between clinical documentation and claims submission than most surgical specialties. Because of this, the interaction between time units, modifier selection, and qualifying circumstance codes means that missing a single documentation field can cascade into a denial, audit, or recoupment across a batch of claims.

Pabau’s claims management software supports structured CPT code tracking across cases, helping anesthesia groups verify that base units, modifiers, and qualifying circumstances are captured consistently before claims are submitted.

Pabau’s digital forms provide configurable pre-anesthesia evaluation templates that prompt providers to document the specific fields CMS requires, including exact start and stop times and qualifying circumstance clinical basis. In addition, for practices wanting to track reimbursements against expected anesthesia rates per the contracted conversion factor, Pabau’s reporting tools surface shortfalls before accounts receivable ages.

Conclusion

CPT code 01200 is a modifier-sensitive, time-documented anesthesia code where billing accuracy depends on three interlocking decisions: selecting the right modifier for the provider type, calculating time units from exact start and stop timestamps, and pairing the claim with the correct ICD-10 diagnosis code at the right level of detail.

Notably, the distinction between 01200 (closed procedures) and 01214 (open total hip arthroplasty) is the most consequential code-selection error in this range and deserves a specific review step in every anesthesia coding workflow.

Ultimately, for practices where documentation and billing are handled separately, Pabau’s integrated approach connects clinical notes directly to claim submission for anesthesia and surgical practices.

Explore how Pabau helps streamline billing and documentation compliance for anesthesia and surgical practices. Book a demo to see the workflow firsthand.

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