Normal, Uncomplicated Anesthesia Modifiers - P1, ZE,ZA

All anesthesia claims require a modifier.  Failure to use the applicable modifier will result in the claim being returned to the provider for correction. 

    Modifier P1 must be billed with the appropriate five-digit CPT-4 anesthesia code to identify a normal, uncomplicated anesthesia provided by a physician.

    Modifier ZE must be billed with the appropriate five-digit CPT-4 anesthesia code to identify a normal, uncomplicated anesthesia provided by a Certified Registered Nurse Anesthetist (CRNA).


Prone Position or Surgical Field Avoidance Modifier

Anesthesia modifier ZA (prone position or surgical field avoidance) should be used only for procedures that have a base value of three (3) units.  These techniques are included in the anesthesia base value of surgical procedures with a base value of more than three.


Services Included In Basic Rate

Medi-Cal does not separately reimburse anesthesiologists for equipment necessary to render anesthesia or the interpretation of laboratory findings (such as blood gases or ECG) normally used by them in administering anesthesia.  Reimbursement for these services is included in the reimbursement for the basic rate.

The complete evaluation routinely performed prior to the administration of anesthesia also is included in the basic rate.  When billing consultation services (CPT-4 codes 99241 – 99275) and anesthesia services for the same recipient, by the same provider, for the same date of service, providers must state that the service was an actual consultation and not the complete pre-anesthesia evaluation in the Remarks field (Box 80)/Reserved for Local Use field (Box 19) of the claim or as an attachment.