Part B Insider (Multispecialty) Coding Alert

Question: Do you have any information on the correct use of modifiers ZA and ZC? I was told these can be used for prone position (ZA) and extracorporeal circulation (ZC), but am not sure about details.

Answer: Modifiers ZA and ZC are anesthesia modifiers specifically used for Medi-Cal insurance prior to March 1, 2011. Services after that date should be reported with appropriate Healthcare Common Procedure Coding System (HCPCS) modifiers, according to their conversion table available at http://files.medi-cal.ca.gov/pubsdoco/newsroom/newsroom_11675_3.asp. 

• Modifier ZA = Modifier 22 (Anesthesia procedures complicated by unusual position or surgical field avoidance) should only be reported in conjunction with anesthesia codes that have a base value of three or fewer units. Unusual position and field avoidance are included in the base value of anesthesia codes with more than three base units. Modifier 22 is defined by Medi-Cal as – “Increased procedural services”.
• Modifier ZC = Physical Status modifier P4 (Anesthesia complicated by extracorporeal circulation) is defined by Medi-Cal as “A patient with severe systemic disease that is a constant threat to life.” Medi-Cal guidelines state that you should also include ICD-9-CM diagnosis code 998.89 (Other specified complications of procedures, not otherwise classified) on any claim with modifier P4 to indicate extracorporeal circulation.