Anesthesia and Pain Management

Anesthesia is the administration of a drug or gas to induce partial or complete loss of consciousness. Services involving administration of anesthesia should be reported by the use of the CPT anesthesia five-digit procedure code plus modifier codes. Surgery codes are not appropriate unless the anesthesiologist or qualified non-physician anesthetist is performing the surgical procedure.

Access the below anesthesia and pain management related information from this page.

Anesthesia Types


  • Beneficiary is drug-induced by mask or IV to a loss of consciousness and are not awakened, even by painful stimulation
  • Many functions of the body will slow down or need help to work effectively; a tube may be placed to assist the beneficiary with breathing
  • Heart rate, blood pressure, breathing and other vital signs are monitored
  • Services include:
    • Pre/post-operative visits
    • Administration of fluids and/or blood
    • Usual monitoring service (e.g., temperature, ECG, blood pressure, oximetry, capnography and mass spectrometry)


  • May be performed as a single injection or with a continuous catheter in which medication is given over a prolonged period (includes epidurals, spinals and other central nerve blocks)
  • Medication delivered to specific level of the spinal cord and/or peripheral nerves
  • Used when loss of consciousness is not desired by a sufficient loss of movement is required

Topical or Local

  • Drug application or injection or a combination of drugs
  • Stops or prevents painful sensation to specific area
  • Not payable by Medicare (bundled into service performed)

Analgesia/Deep Sedation

  • Analgesic drugs act in various ways on the peripheral and central nervous systems to give pain relief without losing consciousness
  • Patient-controlled analgesia not payable by Medicare
  • Airway intervention may be required
  • Non-anesthesia physicians can bill if credentialed, properly trained, etc.
  • Modifier G8 must be appended: Monitored anesthesia care for deep complex, complicated or markedly invasive surgical procedure

Monitored Anesthesia Care (MAC)

  • Drug-induced consciousness with no intervention required to maintain airways; however, cardiovascular is maintained
  • Beneficiary oxygenation, ventilation, circulation and temperature should be evaluated. Close monitoring is necessary to anticipate the need for general anesthesia administration or for the treatment of adverse physiologic reactions
  • By practitioner qualified to administer anesthesia defined by Code of Federal Regulations 42 CFR 482.52(a)
  • Deep sedation/analgesia included in MAC and beneficiary can still respond

Moderate Sedation

  • Drug-induced depression of consciousness where beneficiaries become relaxed and insensitive to pain but remain awake and able to respond to verbal instruction
  • No interventions are required to maintain airway; Cardiovascular function is usually maintained
  • Does not include deep or minimal sedation or MAC
  • Physician or a face-to-face supervised specially trained sedation nurse may perform
  • Must have independent trained observer, for example, Nurse Practitioner (NP), Physician Assistant (PA), Registered Nurse (RN), whose sole duty is to monitor beneficiary's level of consciousness and physiological status; must be present throughout entire diagnostic or therapeutic service; must be identified in notes with credentials
  • Time ends at conclusion of personal contact by physician providing sedation

Covered Providers

General, Regional, and Monitored Anesthesia

  • Anesthesiologist or MD, DO
  • Dentist, oral surgeon or podiatrist qualified to administer under State law
  • Certified Registered Nurse Anesthetist (CRNA) who is supervised by operating room practitioner or by anesthesiologist who is immediately available if needed
  • Anesthesiologist Assistant (AA) under supervision of anesthesiologist who is immediately available if needed
  • Not Covered: Locum tenens not allowed to replace AAs or CRNAs (only MDs); even in rural areas


  • Must meet all State guidelines and licensure to perform the following:
    • Insertion of arterial line
    • Swan-Ganz catheter for monitoring purposes
    • Central venous line
    • Place peripherally inserted central venous catheters (PICC) and central venous pressure (CVP) monitors
  • May perform services at hospitals, offices, free standing clinics and Ambulatory Surgical Centers (ASCs)
  • May supervise two concurrent cases involving student nurse anesthetists and must be present during pre- and post-anesthesia for both cases
  • May bill when providing teaching services for a student; Documentation should show CRNA was continuously present; Append modifier QZ (CRNA service; without medical direction by a physician)
  • Modifier QZ is not used by a CRNA when he/she is the non-physician anesthetist with medical direction by a physician, if performing monitored anesthesiology care or there is medical direction of one qualified non-physician anesthetist by an anesthesiologist

Multiple Anesthesiologists

When multiple anesthesiologists provide services, the anesthesiologist who either started the case or who spent the most time with the beneficiary providing services will submit a claim for the entire case. The time for all anesthesia procedures must be combined and be sure the documentation contains all physicians involved.
When a teaching facility is involved, only the physician who started the case may submit a claim.

Provider Interaction

Medical Direction

Medical direction is a billing distinction describing a higher level of physician involvement in a case than medical supervision. To bill for medical direction, the physician would medically direct qualified providers (e.g., CRNAs, AAs, interns, residents or combinations of these individuals) in two, three or four concurrent cases and perform the following:

  1. Pre-anesthetic exam and evaluation;
  2. Prescribes anesthesia plan;
  3. Personally participates in anesthesia procedures; including induction and emergence;
  4. Ensures procedures in anesthesia plan that he/she does not perform are performed by qualified anesthetist;
  5. Monitors course of anesthesia frequently;
  6. Remains physically present and available for immediate diagnosis and treatment of emergencies; and
  7. Provides any indicated post-anesthesia care.

Medical Supervision

Medical supervision occurs when the anesthesiologist is involved in more than four concurrent cases and when not all seven services under medical direction are performed.


Teaching occurs when the anesthesiologist is training resident in up to two concurrent cases or training a resident in one case, while medically directing in another case. Medicare may reimburse an anesthesiologist when providing teaching services.

The anesthesiologist documents his/her presence during the key and critical portions of the service and append modifier GC (service performed in part by a resident under direction of a teaching physician) following the anesthesia modifier. A physician's presence during only the pre- and post-operative care is not sufficient to receive Medicare payment. The teaching physician must be immediately available if needed to furnish anesthesia during the entire procedure.


Calculation of allowed amounts is based on three factors

  1. Time Units
    • Begin with patient preparation time and end when provider is no longer furnishing anesthesia services. Time is a continuous period from start to finish. Any interrupted time is removed from total time of service
    • Calculated by dividing total number of minutes by 15. Number of units is billed in Item 24G of claim form or electronic equivalent
  2. Base Units
  3. Conversion Factor

Basic formula: Allowable = (Base Unit + Time Unit) x Conversion Factor


  • 00xxx QY (medical supervision by MD)
    • 321 minutes (5 hours, 21 minutes)
  • Search 00xxx QX = 13 base units
    • 321 divided by 15 minutes = 21.4 time units
    • 21.4 plus+ 13.0 base = 34.4 total units
    • 34.4 x CF 2018 $30.89 (Alaska) = $1062.62
  • Both MD (QY) and CRNA (QX) allow at 50%
    • $1062.62 x 50% = $531.31


CPT Codes

  • Head (00100 - 00222)
  • Spine (00600 - 00670)
  • Abdomen-upper/lower (00700 - 00882)
  • Pelvis (01112 - 01190)
  • Knee (01320 - 01444)
  • Forearm/wrist/hand (01810 - 01860)
  • Other (01990 - 01999)

Moderate Sedation

  • 99151 - 99153 (same provider)
    • When moderate sedation is performed in a facility setting (e.g., outpatient hospital, ASC) by the operating surgeon/endoscopist, one unit of 99152 is allowed, but the operating surgeon/endoscopy may not bill 99153, since 99153 is a "technical only" code and Medicare considers that the independent trained observer represents an expense to the facility and may only be billed by the facility.
  • 99155 - 99157 (different provider)
  • G0500 (GI endoscopic; initial 15 minutes)
    • No longer bundled
    • Used with endoscopy codes (43xxx, 453xx and G0105/G0121)


For a listing of anesthesia modifiers and descriptions, see the Modifiers webpage. Some modifiers affect payment (list is not all-inclusive).

Modifier Fee Schedule Allowable
AA 100%
AD 100% - special reimbursement formula
G8, G9* Informational only
QK Limits payment to 50%
QS Informational only
QX Limits payment to 50%
QY Limits payment to 50%
QZ 100%

Physician status (P1-P6) - not recognized by Medicare

Modifier PT is recognized when billed with 10000-69999 (procedure codes), G0500 and 99153 (moderate sedation) and effective January 1, 2018, anesthesia code 00811 only. Modifier 33 is only recognized with Advance Care Planning (ACP) codes 99497-99498.

Bundled (Never Bill Medicare or Beneficiary)

  • Never covered and Advance Beneficiary Notice of Noncoverage (ABN) not allowed: IV starts, Q pain pump, blood gas monitoring and intubation
  • Not separately payable: Drugs, supplies or materials

Discontinued Anesthesia

If a beneficiary has been given anesthesia and the surgeon cancels the surgery (e.g., issue with leaking water on floor in operating room), the code would be allowed based on time.

Anesthesia Overlaps Days

If a surgery and anesthesia overlap days, follow this billing example:

  • Surgery begins at 11:15 p.m. on February 10
  • Surgery ends at 1 a.m. on February 11
  • Do not use date span
  • Bill with start date and total number of minutes

Anesthesia Not Covered

Anesthesia is not covered if the procedure is not covered (e.g., cosmetic surgery).

Anesthetic drugs such as Lidocaine and Marcaine, etc., when administered for chronic pain are not covered.

Part A

If anesthesia is provided in the inpatient hospital or Ambulatory Surgical Center (ASC), reimbursement is provided by Part A Medicare.

Multiple Procedures

A physician bills for the anesthesia services associated with multiple bilateral surgeries by reporting the anesthesia procedure with the highest base unit value. The total time for all procedures is reported in the line item with the highest base unit value.

If the same anesthesia CPT code applies to two or more of the surgical procedures, billers enter the anesthesia code and the number of surgeries to which the modified CPT code applies.

Payment can be made under the fee schedule for anesthesia services associated with multiple surgical procedures or multiple bilateral procedures. Payment is determined based on the base unit of the anesthesia procedure with the highest base unit value and time units based on the actual anesthesia time of the multiple procedures.

Noridian automatically adds modifier 51, when applicable.

Endoscopy and Teaching Physician

If a beneficiary has Esophagogastroduodenoscopy (EGD) and a screening colonoscopy on the same day, Medicare will pay based on endoscopy rules and multiple procedure rules. Both records should be fully documented. To bill Medicare for endoscopic procedures, the teaching physician must be present during the entire viewing (starts at time of insertion of the endoscope and ends at time of removal of the endoscope). Viewing of the entire procedure through a monitor in another room does not meet the teaching physician presence requirement. In most instances, the EGD will use the anesthesia CPT 00813 for the same day.

Anesthesia and Colonoscopy

CPT Modifier Colonoscopy Type CPT/HCPCS Deductible/Coinsurance
00811 PT Screening becomes diagnostic Diagnostic (45378, 45380) Only deductible waived
00812 No modifier needed Screening regardless of findings Screening (G0105, G0121) Both waived
  • Others include 00731, 00732 and 00813
  • CMS Change Request (CR)10181, effective January 1, 2018: 00810 and 00740 deleted


Medical records should include:

  • Clear indication of beneficiary name, date of birth and date of service
  • Must support diagnoses code billed
  • Pre-anesthetic exam and evaluation
  • Detailed exam with pain history and symptoms severity
  • Intra-operative report with anesthesia time (beginning of services, any time spent away from beneficiary and discontinuance of services)
  • Complete operative report
  • Post anesthesia report
  • Imaging reports
  • Activities of Daily Living (ADLs)
  • Conservative treatment such as outpatient therapies or medications
  • What or when does beneficiary feel better or worse

Clearly show number of concurrent services supervised by physician or CRNA


Last Updated Feb 08 , 2024

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