Internal Medicine Coding Alert

Question: We get denials from several insurance companies, stating that modifier 33 is invalid. Are we reporting something we shouldn't?

Connecticut Subscriber

Answer: Modifier 33 (Preventive service) went into effect January 1, 2011, but isn't in the 2011 CPT® book because of publishing deadlines. Payers might be unfamiliar with the modifier and haven't yet built it into their systems.

Some insurers, such as Excellus BlueCross BlueShield, have information regarding modifier 33 on their websites. For example, Excellus shares several guidelines for reporting modifier 33, including:

• CPT® modifier 33 is applicable to preventive services that do not have a unique code for such services (e.g., E&M codes such as, 99401 would not require modifier 33 as this code already indicates a preventive medicine service. However, code 99213 would require modifier 33 when the provider indicates that the service was preventive).

• If multiple preventive medicine services are provided on the same day, then the modifier is appended to the codes for each preventive service rendered on that day.

• Modifier 33 should be used when only preventive services were rendered on that date, not when combined with other non-preventive services.

• CPT® codes identified as inherently preventive, (e.g., screening mammography) should not be appended with modifier 33.

Sometimes, we must educate the payers just like we sometimes must educate ourselves and our physicians. Check for information about modifier 33 on other payer websites or through the AMA website - http://www.ama-assn.org/resources/doc/cpt/new-cptmodifier-for-preventive-services.pdf - that you can share with your payers in question.