Anesthesia and Fee Calculation

by  Christine Woolstenhulme, QMC QCC CMCS CPC CMRS
Jan 29th, 2018 - Reviewed/Updated Dec 7th

Fees for anesthesia services are not calculated or reported the same as for other types of procedures, we have identified some of the most common rules used for reporting anesthesia in this article. Please refer to your MAC Carrier, third-party payer, and the AMA guidelines for more detailed information. 

Conscious Sedation

If conscious sedation is being provided by the same physician doing the procedure refer to codes 99151-99153. 

If another physician is administering the moderate conscious sedation with a separate physician performing the procedure in a facility setting, the other physician may report codes 99155-99157 NOTE: These are not reported for services in a physician's office or freestanding imaging center, for services in the office, home, hospital or consult see the Evaluation Management section 99202-99499. 

Multiple Procedures

When multiple procedures are performed at the same time under the same anesthesia, code the most complex procedure and add the total time for all procedures during the same encounter. 

Status Code

If you are not getting the desired fees, be sure to check the status code and payment indicators (Located under Additional Code Information - PURPLE tab). For example, a CPT code with a "J" status code indicates the following;

There are four elements to consider when calculating anesthesia fees. Medicare accepts base units and time units; however, depending on the third-party payer, they may or may not accept physical status units and/or qualifying circumstances units.

1. Base Unit (of the CPT code)
2. Time (in 15-minute increments)
3. Physical Status (P1, P2, P3, P4, P5, P6)
4. Qualifying Circumstances (four CPT add-on code options, used in addition to Anesthesia Codes: 99100, 99116, 99135, 99140)

NOTE: Read the CPT guidelines for anesthesia for more detailed information (found on each code information page under CPT Chapter/Section Guidelines & Notes). 

FindACodes fee calculator for Anesthesia units can be found on the code information page on the code you need pricing for.  Open the Green bar under FEES>Anesthesia Fee Information. The calculator uses Medicare conversion factors based on geographical location and calculates fees from the base unit and amount of time reported, which may or may not include physical status modifiers and qualifying circumstances.

Note: The calculator uses the location set at the top of your page, this can be changed at any time, using the drop-down arrow. 

Example:  (conversion factor is from 2023 National Unadjusted)

Physical Status Modifiers

Physical Status Modifiers are a classification system under the classifications and guidelines used for more than 60 years by the American Society of Anesthesiologists to communicate a patient's pre-anesthesia medical co-morbidities, Physical status modifiers are also used in determining anesthesia fees. 

For example, 

• A Normal Healthy Patient is a P1
• A patient with mild systemic disease is a P2
• A patient with a severe systemic disease is a P3
• A patient with severe systemic disease that is a constant threat to life is a P4

If the private payer accepts Physical Status (PS) and/or Qualifying Circumstances (QC) as units, these may also be included as part of the fee calculation. Below, the general value of units is shown with each PS Modifier or QC add-on code. Assigning these modifiers and CPT codes may affect payment, for example, according to Moda Health and UnitedHealthcare, they follow the standard Anesthesia Formula below

• P3 modifier is equal to 15 minutes or 1 base unit.
• P4 modifier is equal to 30 minutes or 2 base units
• P5 is equal to 45 Minutes or 3 Base units 

NOTE: Medicare does not recognize Physical status modifiers, Always check the payer policies to see if these rules apply and if the unit values are different:

REF: "Using Physical Status Modifiers with Anesthesia Codes"

Qualifying Circumstances for Anesthesia

Other Modifiers

CMS and other payers require the use of the following modifiers, these are used by qualified non-physician anesthetists when billing for anesthesia services:

These MUST be billed in the first position:

• AA – Anesthesia services performed personally by an anesthesiologist.
• QK – Medical direction by a physician of two, three, or four concurrent anesthesia procedures.
• AD – Medically supervised by a physician, more than four concurrent anesthesia procedures.
• QS – Monitored anesthesia care services
• QY – Medical direction of one CRNA/AA (Anesthesiologist's Assistant) by an anesthesiologist.
• QX – CRNA/AA (Anesthesiologist's Assistant) service with medical direction by a physician.
• QZ – CRNA service without medical direction by a physician.

REF: Anesthesia Documentation Modifiers CMS Pub-100 

Additional Modifiers used with anesthesia codes may include: 

• G8 Monitored anesthesia care (mac) for deep complex, complicated, or markedly invasive surgical procedure
• G9 Monitored anesthesia care for patient who has history of severe cardio-pulmonary condition 

NOTE: The QS modifier can be used by a physician or a qualified non-physician anesthetist and is for informational purposes. Providers must report actual anesthesia time and one of the payment modifiers on the claim.

For more information on CMS billing with modifiers and Anesthesia Billing see the Pub 100-04 Medicare Claims Processing Manual.

Find-A-Code recently added Fees for anesthesia using the applicable Base Units from CMS, UCR, and ACA.  This information can be found on the Anesthesia code information page under Fees and Anesthesia Fee information. To change from CMS to UCR simply select the down arrow next to the Anesthesia Base Units.