CurrentPremera BluecrossPolicy N/A

Anesthesia Guidelines

Defines how Premera Blue Cross calculates and reimburses anesthesia base and time units, required modifiers, special rules for obstetrical anesthesia, qualifying circumstance codes, moderate/conscious sedation, related E&M inclusion, and modifier-specific reimbursement adjustments across applicable Premera/LifeWise lines of business.

Policy Summary

PayerPremera Bluecross

PolicyAnesthesia Guidelines

Policy CodePolicy N/A

Change TypeModifier and reimbursement updates

Effective DateSee individual changes (e.g., 2024-11-24, 2026-03-06)

Next Review Date

Key ActionAppend an appropriate anesthesia HCPCS modifier to each anesthesia service code (00100-01992, 01999); claims submitted without a modifier will be denied.

SourceLink

POLICY UPDATE CHANGES

Added Modifier 23 details; Modifier 23 policy archived effective April 2, 2026.

Added reimbursement statement for modifier QZ: effective 2026-03-06 reimbursement will change from 100% to 85% of provider's applicable Fee Schedule allowed amount.

Effective November 24, 2024, procedure code 01996 does not require an anesthesia modifier.

Added modifier specific details from archived Anesthesia modifier policy and removed archived Anesthesia Modifier policy from cross reference section.

2026-03-06QZ reimbursement change

2024-11-2401996 modifier exception

6Physical status modifiers listed

Scope: This policy defines how Premera Blue Cross calculates anesthesia reimbursement using ASA-established base units plus time units (time begins at anesthesiologist attendance for induction and ends when patient leaves the OR/delivery room; recovery-room time is included in base units), the standard time unit calculation (total minutes ÷ 15, rounded to the nearest hundredth with .5+ rounded up and ≤.4999 rounded down), special obstetrical anesthesia calculation for code 01967 (standard base units allowed; labor management = 3 time units for initial hour and 2 time units for each additional hour; OB units = first 60 minutes ÷ 20, remaining minutes ÷ 30, combine and round per the same rounding rules), modifier requirements and effects (an appropriate anesthesia HCPCS modifier is required on codes 00100–01992 and 01999 or claims will be denied; modifier-specific reimbursement adjustments apply), qualifying circumstance codes (99100–99140) are identified as Medicare Status B and are not eligible for reimbursement, and rules for moderate/conscious sedation (use 99151/99152/99153 if sedation provided by same physician; 99155/99156/99157 if provided by a different clinician; timed in 15-minute increments and require >8 minutes to report).

Scope and Key Thresholds

Effective date

Last review03/12/26

Next review

Policy statusCURRENT

Anesthesia time unit calculation (standard)total minutes ÷ 15; rounded to nearest whole hundredth; .5+ round up; ≤.4999 round down

OB anesthesia calculation (01967)first 60 minutes ÷ 20; remaining minutes ÷ 30; combine and round to nearest whole hundredth; .5+ round up; ≤.4999 round down

Moderate sedation minimum time to report>8 minutes (more than half of 15-minute increment)

QZ reimbursement change effective date2026-03-06 (reimbursement changes from 100% to 85%)

Anesthesia coverage & calculation criteria

Definition of anesthesia attendance/time units

Definition of anesthesia attendance/time units — covered when ALL of the following are met:

The period of time on which anesthesia time units are based begins when the anesthesiologist is first in attendance with the patient for the purpose of induction of anesthesia and ends when the patient leaves the operating room or delivery room. Time spent in the recovery room is included in anesthesia base units and no additional benefits are provided.

For a procedure to be considered 'anesthesia attendance' and not standby, ALL of the following must occur: the service is requested by the attending physician; the anesthesiologist documented presence for the entire procedure and provided all usual services except actual administration of anesthetic agent; and anesthesia attendance must be medically necessary for the patient's surgical procedure and condition.

American Society of Anesthesiologists (ASA) base units are used to establish base units. For time-based anesthesia reimbursements (unless otherwise noted), total anesthesia units are calculated based on a four-unit hour. Total anesthesia minutes are divided by 15 and rounded to the nearest whole hundredth decimal point using standard rounding methodology: .5 unit or more is rounded up to the next whole unit; .4999 units or less is rounded down to the next whole unit.

Obstetrical anesthesia time calculation

Obstetrical anesthesia time calculation — covered when ALL of the following are met:

Standard base units are allowed for obstetrical delivery epidural anesthesia (CPT 01967). Labor management is allowed 3 time units for the initial hour of the block and 2 time units for each additional hour.

To calculate OB anesthesia units: divide the first 60 anesthesia minutes by 20 and divide remaining minutes by 30; combine the resulting units and round to the nearest whole hundredth decimal point using standard rounding methodology: .5 unit or more rounds up; .4999 or less rounds down.

When applying the OB-specific calculation, include the documented anesthesia attendance time that begins when the anesthesiologist is first in attendance for induction/placement and ends when the patient leaves the delivery room; time in recovery is included in base units and not paid separately.

Obstetrical daily hospital management exception

Obstetrical daily hospital management exception — covered when ALL of the following are met:

The Plan recognizes an exception for obstetrical daily hospital management modifier (CPT 01996) when appropriately documented. When modifier 01996 is reported, follow modifier and documentation rules to determine allowance; ensure the modifier is supported by medical record documentation.

Provider must append an appropriate anesthesia provider modifier (e.g., AA, QK, QX, QY, QZ, AD) to each anesthesia service including obstetrical services; anesthesia services submitted without a modifier will be denied reimbursement.

Related care / E&M inclusion

Related care / E&M inclusion — covered when ALL of the following are met:

Evaluation and management (E&M) services submitted one day preoperatively, on the same date of service, or one day postoperatively are included with any anesthesia procedure assigned a global day period of 'XXX' per CMS; these E&M services are considered part of the global anesthesia service and are not separately payable in that window.

A pre-anesthesia evaluation by the anesthesiologist when the procedure is delayed is considered an integral part of the subsequent anesthesia services and is not separately payable. A pre-anesthesia evaluation when surgery is canceled may be covered at the level of care rendered (hospital or office visit) if documented.

Local anesthesia is considered an integral part of the surgical procedure and no additional benefits are provided. Nerve blocks reimbursed on relative value units only do not require anesthesia time for additional time-based reimbursement.

Per ASA billing criteria

Per ASA billing criteria — covered when ALL of the following are met:

When multiple surgical procedures are performed during a single anesthetic, report the anesthesia procedure code with the highest base units as the primary anesthesia code. Base units for additional procedures performed during the same anesthetic are not reported separately.

Total anesthesia time for a single anesthetic that includes multiple procedures is combined into one continuous anesthesia time calculation beginning when the anesthesiologist first attends the patient for induction of anesthesia and ending when the patient leaves the operating or delivery room. Use this combined time to calculate time units (divide total minutes by 15 and round per policy unless OB-specific calculation applies).

For increased anesthesia service due to additional work, additional time units should be billed instead of modifier 22; physical status modifiers (P1–P6) may be added when warranted and additional unit values may be allowed per ASA Relative Value Guide. Qualifying circumstance codes (99100–99140) may be applied when indicated and documented but are identified as Medicare Status B and are not eligible for reimbursement.

If more than one anesthesia provider level is involved (e.g., medical direction of CRNAs), append the appropriate anesthesia HCPCS modifier (AA, QK, QX, QY, QZ, AD). Reimbursement may be adjusted based on modifier; anesthesia services without a provider-level modifier will be denied.

Coding groups and modifiers

Obstetrical AnesthesiaCPT/HCPCSCovered

01967	Neuraxial labor analgesia/anesthesia for planned vaginal delivery (includes repeat subarachnoid needle placement, drug injection and/or replacement of epidural catheter during labor)
01996	Daily hospital management of epidural or subarachnoid continuous drug administration (does not require an anesthesia modifier effective 2024-11-24)

Anesthesia procedure codes rangeCPT/HCPCSCovered

00100-01992	Anesthesia procedure codes — modifiers required to identify provider level
01999	Anesthesia procedure code (other)

Moderate/Conscious Sedation CodesCPTCovered

99151	Moderate sedation by same physician - initial 15 minutes, patient <5 years
99152	Moderate sedation by same physician - initial 15 minutes, patient ≥5 years
99153	Add-on each additional 15 minutes for same physician
99155	Moderate sedation by other physician - initial 15 minutes, patient <5 years
99156	Moderate sedation by other physician - initial 15 minutes, patient ≥5 years
99157	Add-on each additional 15 minutes for other physician

Qualifying Circumstances (not reimbursed)CPTNot Covered

99100	Anesthesia for patient of extreme age (<1 yr or >70) — add-on; Medicare Status B; not eligible for reimbursement
99116	Anesthesia complicated by utilization of total body hypothermia — add-on; not eligible for reimbursement
99135	Anesthesia complicated by utilization of controlled hypotension — add-on; not eligible for reimbursement
99140	Anesthesia complicated by emergency conditions — add-on; not eligible for reimbursement

Anesthesia ModifiersModifier

23	Unusual Anesthesia
AA	Anesthesiology services performed personally by an anesthesiologist
AD	Medical supervision by a physician: >4 concurrent anesthesia procedures
QK	Medical direction of 2-4 concurrent anesthesia procedures
QX	CRNA service: with medical direction by a physician
QY	Medical direction of one CRNA by an anesthesiologist
QZ	CRNA service: without medical direction by a physician; reimbursement change to 85% effective 2026-03-06
P1	Physical Status Modifier P1
P2	Physical Status Modifier P2
P3	Physical Status Modifier P3

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Modifier requirements and effects

Modifiers required to identify provider level and may affect reimbursement:

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title':'Modifier requirements and effects'

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Modifier-specific rules and reimbursement adjustments

Recognized modifiers and special reimbursement rules:

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title':'Modifier-specific rules and reimbursement adjustments'

_done_

Qualifying circumstances codes

Qualifying circumstances may apply but are not eligible for reimbursement per policy:

Qualifying circumstances codes not reimbursed: Qualifying circumstance codes (99100-99140) may be applied when indicated and documented; these codes are identified as Medicare Status B codes and are not eligible for reimbursement

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title':'Qualifying circumstances codes'

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Billing, documentation & operational actions

Billing Rule

Append anesthesia modifier to anesthesia service codes

An appropriate anesthesia HCPCS modifier must be appended to each anesthesia service code (00100-01992, 01999); claims submitted without a modifier will be denied.

Affected codes: 00100-01992, 01999
Claims submitted without a modifier will be denied reimbursement

Billing Rule

Use special OB calculation for 01967

When billing 01967, calculate units using first 60 minutes ÷20 and remaining minutes ÷30, combine and round per policy rules.

Calculation steps: first 60 minutes ÷ 20; remaining minutes ÷ 30
Rounding rule: .5 unit or more rounded up; .4999 units or less rounded down

Billing Rule

01996 modifier exception

Do not append an anesthesia modifier to code 01996 effective 2024-11-24.

Effective date: 2024-11-24

Billing Rule

QZ reimbursement adjustment effective date

For QZ (CRNA without medical direction), adjust reimbursement to 85% of applicable Fee Schedule for dates of service on and after 2026-03-06.

Modifier: QZ
Effective date: 2026-03-06
Reimbursement change: 85% of provider's applicable Fee Schedule allowed amount

Billing Rule

Use time units for increased anesthesia service instead of modifier 22

For increased anesthesia service, bill additional time units rather than modifier 22, or bill with physical status modifiers to identify additional work.

Documentation Required

Document anesthesia attendance for non-standby services

Document that service was requested by attending physician, anesthesiologist was present for entire procedure and provided usual services (except actual administration if applicable), and medical necessity for anesthesia attendance.

The service is requested by the attending physician
The anesthesiologist documented presence for the entire procedure and provided all usual services except actual administration of anesthetic agent
Anesthesia attendance must be medically necessary for the patient's surgical procedure and condition

Billing Rule

Report only highest base anesthesia code when multiple procedures

When multiple surgical procedures occur during single anesthetic, report only the anesthesia code with highest base value and combine total anesthesia time for all procedures.

OpenPayer

Anesthesia Guidelines

Policy overview

Anesthesia coverage & calculation criteria

Coding groups and modifiers

Billing, documentation & operational actions

Moderate / Conscious Sedation reporting

Key definitions

Policy changes & effective dates