How to bill anesthesia

Medi-Cal has not adopted the “qualifying circumstances” codes (99100 – 99140).  Claims submitted with these codes will be denied or returned to the provider for correction.


Billing Anesthesia Services

Anesthesia services (CPT-4 codes 00100 – 01999) are reimbursed when medically necessary.  To bill for anesthesia services, use the five-digit CPT-4 code applicable to the procedure with the appropriate modifier. 

Billing in 15-Minute Incrementsof Anesthesia Time

To bill anesthesia time units, enter the number of 15-minute increments of anesthesia time in the Service Units/Days or Units box on the claim form, using the same billing line as the procedure code.  Each 15-minute increment equals one time unit.  Increments of time less than five minutes are not reimbursable except when the total anesthesia time being billed is less than five minutes.  For more information, see the “Total Anesthesia Time Unit:  Less Than Five Minutes” section.

Total Anesthesia Time Unit:More Than Five Minutes

The last anesthesia time increment rendered may be rounded up to a whole unit if it equals or exceeds five minutes.  If the last anesthesia time increment provided is less than five minutes, it may not be billed as an additional anesthesia time unit. 


Time Unit Billing Examples


•    For 49 minutes of anesthesia time actually spent with the patient, enter 3 in the Service Units/Days or Units box. 
(The four-minute increment is not reimbursable.)
•    For 80 minutes of anesthesia time actually spent with the patient, enter 6 in the Service Units/Days or Units box. 
(The five-minute increment is reimbursable.)

    Note:    Do not include the base units for the procedure performed since the base unit payment is automatically included in the reimbursement rate.  Billing for the base units could be considered a fraudulent billing practice.