This article explains anesthesia billing with guidelines and official definitions.
The following services are included in general anesthesia administration;
- administration of fluids and blood;
- preoperative and postoperative visits;
- usual monitoring (for example, blood pressure, ECG, temperature, oximetry, mass spectrometry, or capnography) as defined by ASA (American Society of Anesthesiologists) and/or CPT coding guidelines; and
- anesthesia care during the procedure.
Click on a link to go to the section of the article.
- Payment Calculation Information
- How To Fill Out Anesthesia Claims
- Modifiers For Anesthesiologists
- Modifier For CRNAs
- Basics Of Payment And Reimbursement
- Post-Operative Pain Management
- Anesthesia CPT Codes
- Anesthesia Modifiers
Below are the most common terms used for anesthesia billing.
Meaning: Anesthesia is the introduction of a substance into the body by external or internal means that causes loss of sensation (feeling) without or wirth the loss of consciousness.
Meaning: An anesthesiologist is a physician (M.D. or D.O.) specializing in anesthesiology.
Anesthesiologists are medical doctors who complete an additional three years of specialized training in an accredited anesthesiology residency program after obtaining their medical degree and completing their internship.
They are certified by the American Board of Anesthesiology. Medical doctors have a wide range of knowledge about medications, medical care for diseases, how the human body works, and how it responds to the stress of surgery.
1.3 Anesthesia Specialists
Meaning: Anesthesia specialists are responsible for making informed medical decisions to provide comfort and maintain vital life functions while receiving anesthesia and in recovery.
Anesthesia specialists include anesthesiologists and qualified nurses or dental anesthetists.
Meaning: Most anesthetists are nurses who have graduated from an accredited nurse anesthetist program and have been certified by the American Association of Nurse Anesthetists to become certified registered nurse anesthetists (CRNA).
Nurse anesthetists are advanced practice nurses with specialized skills in anesthesia administration. A nurse anesthetist is usually supervised by an anesthesiologist or a surgeon, although law and practice may vary by state.
1.5 Certified Registered Nurse Anesthetist (CRNA)
Meaning: A registered nurse is licensed by the state where the nurse practices. The CRNA must be certified by the Council on Certification of Nurse Anesthetists or the Council on Re-certification of Nurse Anesthetists.
The CRNA must have graduated within the past 24 months from a nurse anesthesia program that meets the standards of the Council on Accreditation of Nurse Anesthesia Educational Programs and be awaiting initial certification.
1.6 Concurrent Medically Directed Anesthesia Procedures
Meaning: Concurrency is defined as the maximum number of procedures the physician medically directs within a single procedure and whether these other procedures overlap.
The physician can medically direct two, three, or four concurrent procedures involving qualified CRNAs.
1.7 Medical Direction
Meaning: Medical direction occurs when an anesthesiologist is involved in two, three, or four concurrent anesthesia procedures or a single anesthesia procedure with a qualified CRNA.
1.8 Medical Supervision
Meaning: Medical Supervision occurs when an anesthesiologist is involved in five or more concurrent anesthesia procedures.
1.9 Personally Performed Anesthesia
Meaning: The applicable allowable charge is determined by the base unit for the anesthesia code and one time unit per 15 minutes of anesthesia time (unless otherwise stated) if:
- the physician personally performed the entire anesthesia service alone;
- the physician is continuously involved in a single case involving a student nurse anesthetist; or;
- the physician and the CRNA are involved in one anesthesia case, and each service is found to be medically necessary upon appeal. Documentation must be submitted by both the CRNA and the physician to support payment of the full fee for each of the two providers through our appeal process. The physician reports modifier AA, and the CRNA reports the QZ modifier for a nonmedically directed case.
2. Payment Calculation Information
The following information includes payment calculation information such as time and base units.
3.1 Time Units
Time units will be determined by using the total time in minutes spent performing the procedure. Fifteen minutes is the equivalent of 1 time unit. Time units will be rounded to the tenth.
If the procedure lasts 49 minutes, the time units in this example would be 3.26 or 3.3-time units.
The units field 24G of the HCFA form should reflect the number of minutes the provider spent on the procedure.
Anesthesia time begins when the provider of services physically prepares the patient for induction of anesthesia in the operating room (or equivalent) and ends when the provider of services is no longer in constant attendance. The patient may safely be placed under postoperative supervision.
3.2. Base Units
The basis for determining the base units for anesthesia CPT codes is the Relative Value Guide published by the American Society of Anesthesiologists (ASA). HMO Blue Texas and Blue Cross and Blue Shield of Texas shall implement any yearly update of the Relative Value Guide within 60 days of receipt.
The exception to this will be Covered Services provided on dates between the receipt of the Relative Value Guide published by ASA and implementation of the updated material. Claims incurred during the exception period will be priced based on the Relative Value Guide on December 1st of the prior calendar year.
Newly established codes will be paid at HMO Blue Texas and Blue Cross and Blue Shield of Texas determined rates until the annual update is implemented.
Physical status modifiers can be billed by anesthesiologists and/or CRNAs:
- No base units for Modifier P1 (a normal healthy person)
- No base units for modifier P2 (a patient with mild systemic disease)
- One base unit for modifier P3 (a patient with severe systemic disease)
- Two base units for modifier P4 (a patient with severe systemic disease that is a constant threat to life)
- Three base units for modifier P5 (a moribund patient who is not expected to survive without the operation)
- No base units for modifier P6 (a declared brain-dead patient whose organs are being removed for donor purposes)
3. How To Fill Out Anesthesia Claims
Anesthesia services by anesthesiologists or CRNAs must be filed using the appropriate anesthesia CPT code (beginning with zero). One of the modifiers for anesthesia must be submitted with each service billed.
Failure to submit one of the modifiers will result in a returned or rejected claim. The allowable charge for medically necessary anesthesia services will be determined based on the applicable anesthesia conversion factor and the modifier submitted on the claim.
The applicable anesthesia modifier will determine the percentage of the anesthesia conversion factor to be applied to each claim without regard to the order in which claims are received for both CRNAs and anesthesiologists.
If there are groups from which a CRNA and an anesthesiologist work together on a case, continue the single claim records to contain multiple line items for anesthesia services.
Individual claims are accepted for every portion of the anesthesia service performed if more than one provider was involved.
Every line item must indicate which provider performed the service by identifying the corresponding provider’s NPI on the CMS-1500 claim form in block 24J (or the equivalent field on electronic claims).
CRNAs and Anesthesiologists must include the following to ensure reimbursement when billing for anesthesia services;
- procedure anesthesia codes;
- one of the required anesthesia modifiers;
- the minutes of administration; and
- identification by including any performing provider/provider’s NPI on the claim form.
Anesthesia for multiple surgical procedures in the same anesthesia session must be billed on one claim line using the most appropriate anesthesia code with the total anesthesia time spent reported in Item 24G on the claim form.
The only secondary procedures not to be billed in this manner are tubal ligations and hysterectomies.
Anesthesia claims with a total anesthesia time of fewer than 10 minutes or greater than 224 minutes must be submitted in hard copy with the appropriate anesthesia graph attached.
Anesthesia claims for multiple but separate operative services performed on the same recipient on the same date of service must be submitted in hard copy, with a cover letter indicating the above.
The anesthesia graphs from the surgical procedures should be included, and the claim with attachments should be submitted to Unisys at the address below.
When anesthesia claims deny with error codes 749 (delivery billed after hysterectomy was done) or 917 (lifetime limits for this service have been exceeded), a new claim must be submitted to Unisys at the address below with a cover letter describing the situation.
4. Modifiers For Anesthesiologists
The following modifiers can be reported for anesthesia services provided by an anesthesiologist.
Modifier AA: Anesthesia services personally performed by the anesthesiologist
Modifier AD: Supervision of more than four procedures
Modifier QK: Medical Direction of two, three, or four concurrent anesthesia procedures
Modifier QY: Medical Direction of one CRNA by an anesthesiologist
5. Modifier For CRNAs
The following modifiers can be billed for anesthesia services provided by CRNAs.
Modifier QX: Anesthesia, CRNA medically directed.
Modifier QZ: Anesthesia, CRNA not medically directed.
6. Basics Of Payment & Reimbursement
Three base units per procedure are allowed when the anesthesiologist is involved in rendering more than four procedures concurrently or is performing other services while directing the concurrent procedures.
An additional time unit can be recognized if the physician can document he/she was present at induction. Modifier AD is appropriate when anesthesia service is medically supervised.
The fee schedule allowance for anesthesia services is based on a calculation that includes the anesthesia base units assigned to each anesthesia code, the anesthesia time involved, and the appropriate area conversion factor.
The fee schedule payment for personally performed procedures is based on the full base unit and time units (one for every fifteen minutes) of service if the physician personally performed the entire procedure.
Modifier AA can be reported when the anesthesia services are personally performed.
6.1 Payment At Medically Directed Rate
A Payment for each anesthesia service is 50% of the allowance when the anesthesia provider is medically directing a qualified anesthetist (Anesthesiologist, CRNA, or an assistant). The provider can medically direct two, there, or four procedures.
Medically directed anesthesia services are to be billed as:
- The physician can bill modifier QY for the medical direction of one CRNA by a physician or QK.
- The assistant, CRNA, or anesthesiologist bills the physician’s modifier QX.
6.2 Payment At Non-Medically Directed Rate
Full payment for the anesthesia service provider by each provider is allowed if it is medically necessary for the CRNA/Assistant and the anesthesiologist and to be fully involved during an anesthesia procedure.
Submitted the following documentation for each provider for reimbursement:
- Bill modifier AA and modifier 22 with attached supporting documentation if the anesthesia services are personally performed by an anesthesiologist.
- Bill modifier QZ and modifier 22 with documentation for CRNA/Anesthesiologist Assistant services without medical direction by a physician.
6.3 Anesthesia Formula
The allowance for anesthesia services is based on the following formula: (Time Units + Base Units) X Conversion Factor = Allowance.
The following formulas are used to determine payment for anesthesia services:
- The participating physician is not medically directing: (Base Units + Time Units) x Participating Conversion Factor = Allowance.
- The non-participating physician is not medically directing: (Base Units + Time Units) x Non-Participating Conversion Factor=Allowance.
- The participating physician is medically directing: (Base Units + Time Units) x Participating Conversion Factor = Allowance x 50%.
- The non-participating physician is medically directing: (Base Units + Time Units) x Non-Participating Conversion Factor = Allowance x 50%
- Non-medically directed CRNA: (Base Units + Time Units) x Participating Conversion Factor = Allowance
- CRNA medically directed: (Base Units + Time Units) x Participating Conversion Factor = Allowance x 50%
7. Post-Operative Pain Management
When billing for surgical anesthesia (00 series CPT codes) and for post-operative pain management, the codes must appear on the same claim. If billed separately, the claim for the post-operative pain management will be denied due to no preauthorization being on file.
8. Anesthesia CPT Codes
CPT codes for anesthesia services should be billed under the rendering providers NPI number using CPT code range 00100 – 01999; there is no separate payment for the supervision of a CRNA .
Click here for a complete list with anesthesia CPT codes and base units.
9. Anesthesia Modifiers
Anesthesia modifiers are required by CMS. Claims without the following appropriate modifier will be returned.
Modifier AA: Anesthesia services performed personally by anesthesiologist.
Modifier QX: CRNA with medical direction by a physician.
Modifier QZ: CRNA without medical direction by a physician
Click here for the complete list of anesthesia modifiers with guidelines.