CurrentHumanaPolicy CP2017001

Anesthesia Services (Revised)

Humana Medicare Advantage application policy describing billing, reporting and reimbursement rules for professional anesthesia services (CPT 00100-01999) including time reporting, modifiers, unit calculations, qualifying circumstance and physical status modifiers, and rules for post-operative pain management and multiple procedures.

Policy Summary

PayerHumana

PolicyAnesthesia Services (Revised)

Policy CodePolicy CP2017001

Change TypeRevised (04/2026)

Effective Date

Next Review Date

Key ActionReport anesthesia services using a CPT code in the 00100-01999 range and follow Humana's time, modifier and documentation requirements for reimbursement.

SourceLink

POLICY UPDATE CHANGES

Policy revision date 04/2026 noted in header.

00100-01999Required CPT range

AA,QK,QX,QY,QZ,ADKey modifiers specified

99100,99116,99135,99140Qualifying add-on codes

Policy summary

This Humana Medicare Advantage policy (CP2017001) applies to professional anesthesia services and establishes billing and reimbursement rules for CPT codes 00100-01999, covering calculation of allowable payment using base units, time units and the conversion factor; requirements for reporting actual anesthesia time in one-minute increments; modifier usage and reimbursement percentages including special handling for AD (three base units with one additional unit only if supervising physician present at induction); treatment of qualifying circumstance and physical status modifiers (Medicare Advantage does not allow additional units for P1–P6 or qualifying circumstance add-on codes 99100, 99116, 99135, 99140); criteria and documentation requirements for separate reimbursement of post-operative pain management procedures (separate record, surgeon request, patient consent, append modifier 59, XE or XU, and time not included in intra-operative anesthesia time); rules for multiple procedures during a single anesthesia session (report only the code with the highest base units and report combined time); and non-reimbursable situations such as anesthesia services billed by the attending surgeon.

Coverage & reimbursement criteria

Reporting Anesthesia Services

Humana requires anesthesia services to be reported using a CPT code in the 00100-01999 range.

Report anesthesia services using a Current Procedural Terminology (CPT) code in the 00100 - 01999 range.

Anesthesia Reimbursement Calculation

Humana plans calculate reimbursement as follows for time-based anesthesia services:

Anesthesia reimbursement formula: (CMS Base Value Unit + Time Units + Anesthesia Physical Status Modifier Unit, if applicable) x Conversion Factor = Anesthesia Allowable

This calculation does not apply to anesthesia services that are not time-based.

Reporting Anesthesia Time

Requirements for reporting anesthesia time:

Report anesthesia time: Report actual anesthesia time in one-minute increments in the anesthesia minutes field.

Some anesthesia services are not time-based and are excluded from this requirement.

Multiple Procedures During Single Anesthesia Session

Reporting rule when multiple procedures performed during single anesthesia session:

Multiple procedures during single anesthesia session: Report only the anesthesia service code with the highest base unit value and report the combined time for all procedures with that code.

Non-Reimbursable Reporting

Humana does not reimburse certain anesthesia reporting situations:

Non-reimbursable reporting: Humana plans do not reimburse for anesthesia services reported by the attending surgeon.

Codes and modifiers

Anesthesia CPT range requiredCPTCovered

00100-01999

Anesthesia services CPT code range required to report anesthesia services

Qualifying Circumstance Add-on Codes (Commercial additional units allowed)CPTCovered

99100	Anesthesia for patient of extreme age (add-on)
99116	Anesthesia complicated by utilization of total body hypothermia (add-on)
99135	Anesthesia complicated by utilization of controlled hypotension (add-on)
99140	Anesthesia complicated by emergency conditions (add-on)

Monitored Anesthesia Care ModifiersModifier

G8	Monitored anesthesia care (MAC) for deep complex procedures
G9	Monitored anesthesia care for patient with severe cardio-pulmonary condition
QS	Monitored anesthesia care service

Anesthesia Service Modifiers Affecting Payment ShareModifier

AA	Anesthesia services performed personally by anesthesiologist (100%)
AD	Medical supervision by physician: more than four concurrent anesthesia procedures (special AD unit rules applied)
QK	Medical direction of 2-4 concurrent anesthesia procedures (50%)
QX	CRNA service: with medical direction by a physician (50%)
QY	Medical direction of one CRNA by an anesthesiologist (50%)
QZ	CRNA service: without medical direction by a physician (100%)

Physical Status ModifiersModifier

P1	Normal healthy patient
P2	Patient with mild systemic disease
P3	Patient with severe systemic disease
P4	Patient with severe systemic disease that is a constant threat to life
P5	Moribund patient not expected to survive without operation
P6	Declared brain-dead patient whose organs are being removed for donor purposes

Qualifying Circumstance Codes (Units Allowed)

Humana commercial vs Medicare Advantage handling of qualifying circumstance codes:

Qualifying circumstance codes are add-on codes and should be billed in addition to the primary anesthesia service code.

Medicare Advantage units: Medicare Advantage plans: No additional units for qualifying circumstance codes 99100, 99116, 99135, 99140.

Commercial units: Commercial plans: 99100 = 1 additional unit; 99116 = 5 additional units; 99135 = 5 additional units; 99140 = 2 additional units.

Anesthesia Physical Status Modifiers (Units Allowed)

Humana commercial vs Medicare Advantage handling of P1-P6:

Medicare Advantage physical status units: Medicare Advantage plans: No additional units for physical status modifiers P1-P6.

Commercial physical status units: Commercial plans: P1 = No additional units; P2 = No additional units; P3 = 1 additional unit; P4 = 2 additional units; P5 = 3 additional units; P6 = No additional units.

Reporting order for physical status modifiers: Physical status modifiers should be reported after modifier AA, AD, QK, QX, QY or QZ.

Billing, modifier and documentation rules (actionable)

Billing Rule

Use CPT 00100-01999 for anesthesia services

Report anesthesia services using CPT codes in the 00100-01999 range. For anesthesia professional services, report CPT codes within 00100-01999 only.

00100-01999

Billing Rule

Report anesthesia time in one-minute increments

Report actual anesthesia time in one-minute increments in the anesthesia minutes field. Do not apply this time-reporting rule to anesthesia services that are not time-based.

Billing Rule

Append appropriate anesthesia modifiers

Append modifier AA, AD, QK, QX, QY or QZ to the anesthesia service code as appropriate. If the service is monitored anesthesia care, append the monitored anesthesia care modifier (G8, G9 or QS) after the AA/AD/QK/QX/QY/QZ modifier.

Billing Rule

Modifier-specific reimbursement rules

Humana applies modifier-specific reimbursement: AA and QZ are reimbursed at 100% of the provider's contracted rate or base maximum amount; QK, QX and QY are reimbursed at 50%. For modifier AD, Humana calculates reimbursement using three base units regardless of the procedure’s base units; one additional unit is allowed only when documentation confirms the supervising physician was present at induction. Additional units for length of time, qualifying circumstance codes or physical status modifiers are not allowed with AD.

AD — special handling: calculated with 3 base units; +1 unit if supervising physician present at induction
QK — 50% reimbursement
QX — 50% reimbursement
QY — 50% reimbursement
AA — 100% reimbursement
QZ — 100% reimbursement

Documentation Required

Documentation for separate reimbursement of post-operative pain management

To qualify for separate reimbursement of a post‑operative pain management procedure, maintain medical record documentation separate from the anesthesia record that confirms the procedure was for post‑operative pain management, documents procedure details, confirms the surgeon requested the anesthetist perform it, and confirms patient consent. The time to place/administer the post‑operative pain management procedure must not be included in intra‑operative anesthesia time. Append modifier 59, XE or XU to indicate a distinct procedural service.

Append modifiers: 59, XE, XU
Separate medical record (distinct from anesthesia record)
Documentation that procedure was for post‑operative pain management and intra‑op anesthesia adequacy is not dependent on it
Procedure details, surgeon request, patient consent
Exclude placement/administration time from intra‑operative anesthesia time

Billing Rule

Multiple procedures during single anesthesia session

When multiple procedures occur during a single anesthesia session, report only the anesthesia service code with the highest base unit value and report the combined time for all procedures with that single code.

Denial Risk

Nonpayment for surgeon-reported anesthesia

Humana plans do not reimburse anesthesia services reported by the attending surgeon. Submitting anesthesia services on a surgeon’s claim risks denial of payment.

Post-operative pain management — separate reimbursement criteria

Reimbursement for Post-Operative Pain Management Procedures (Separate Reimbursement Criteria)

A post-operative pain management anesthesia procedure may be reimbursed separately when ALL of the following are satisfied:

Separate medical record: Medical record documentation of the post-operative pain management procedure must be separate from the anesthesia record.

Confirm purpose and independence from intra-operative anesthesia: Documentation must confirm the procedure was for post-operative pain management and the adequacy of the intra-operative anesthesia is not dependent on the epidural injection or nerve block.

Procedure details: Documentation must include details about the procedure itself.

Surgeon request: Documentation must confirm the surgeon requested the anesthetist administer the procedure.

Patient consent: Documentation must confirm the patient consented to the post-operative pain management plan and procedure.

Time exclusion: The time spent placing or administering a post-operative pain management procedure cannot be included in the intra-operative anesthesia time.

Modifier 59/XE/XU: Append modifier 59, XE or XU to the post-operative pain management procedure code to indicate a distinct procedural service was performed.

Timing allowed: Post-operative pain management procedures may be administered pre-operatively, intra-operatively or post-operatively.

Not reimbursed when same physician reports surgical charge: Post-operative pain management procedures are not separately reimbursed when reported by the same physician reporting the procedure or surgical charge.

Note

OpenPayer

Anesthesia Services (Revised)

Policy summary

Coverage & reimbursement criteria

Codes and modifiers

Billing, modifier and documentation rules (actionable)

Key terms and definitions

Post-operative pain management — separate reimbursement criteria

Policy changes