Add-on Codes

Add-on codes are procedure codes that indicate additional work associated with another primary procedure. Add-on codes can be reimbursed when reported with the primary procedure code by the same practitioner.

Add-on codes may be identified in three ways:

1. The code is listed as a Type 1, Type 2, or Type 3 add-on code.
2. In the Physician Fee Schedule Lookup Tool, add-on codes generally have a global surgery period of “ZZZ.”
3. In the current year CPT Manual, an add-on code is designated by the symbol “+.” The code descriptor of an add-on code generally includes phrases such as “each additional” or “(List separately in addition to primary procedure).” This information will also be listed in Appendix D.

There are three types of add-on codes:

• Type 1: Eligible for payment if billed with an appropriate primary code for the same practitioner for the same patient on the same date of service. Type 1 add-on codes are only reimbursed when submitted with an acceptable primary code.
• Type 2: These codes are not associated with a specific list of primary procedure codes.
• Type 3: These codes are associated with some specific primary procedure codes identified in the CPT Manual. In addition to the primary codes with which they are payable, they may also be reimbursed if they are submitted with other primary procedure codes, if documentation in the patient’s medical record supports the medical necessity of the add-on code.

The add-on code listing which includes the types and process for determination are available at Medicare National Correct Coding Initiative Add-on Code Edits.

Posted 3/3/2025