May 2, 2019
Add-on codes represent an additional service associated with a primary or parent procedure code. For most of the primary/parent codes and their respective add-on codes, the code pair combinations are from the same provider on the same date of service.
In the 2019 CPT Codebook, there are new add-on code combinations that can be billed on the same or different dates of service as noted in the parenthetical note after the add-on code entry. CPT and HCPCS add-on codes can be identified by key phrases in the code description which include, but are not limited to the following:
- List separately in addition to primary procedure
- Each additional
- Done at time of other major procedure
Submitting an add-on code by itself without its designated primary or parent code will cause an edit and be denied reimbursement. Add-on codes are tied to the status of the primary/parent code. If the primary or parent code is denied reimbursement, the add-on code will also be denied reimbursement. Add-on codes and their respective parent/primary codes can be found in the industry sources below:
American Medical Association CPT Professional Codebook:
- Add-on codes are identified by the plus symbol “+” notation next to the procedure code
- Appendix D in the same codebook also lists a summary of add-on codes in the codebook
- The primary/parent procedure code(s) associated with these add-on codes are found in the codebook in a parenthetical instruction after each add-on code indicating which primary codes should accompany the add-on code
- When there is a specific primary/parent code listed in the codebook, the add-on code must not be reported with a procedure code(s) other than that which is listed as the primary/parent code(s).
CMS Add-On Code Listing:
- CMS maintains a listing of add-on CPT and HCPCS codes
- Add on codes are also identified in the National Physician Fee Schedule with a “Global Days Indicator” code of “ZZZ”
- Some add-on codes with the Global Days Indicator code of “ZZZ” are classified as Medicare Status B codes on the CMS National Physician Fee Schedule. These codes will not be reimbursed even if billed with an appropriate primary/parent code
Review the payment policy “Add-On Codes” for additional information on correct billing of add-on codes.