Tips for Add-on Codes

Tips for Add-on Codes

All add-on codes are exempt from the “multiple procedure” concept, per CPT® instructions. As such, you never would append modifier 51 multiple procedures to a designated add-on code. Other important points to remember about add-on codes include:

  • They are denoted in CPT® with a “+” to the left of the code
  • The CPT® code descriptor will include some variation of the phrase, “list separately in addition to code for primary procedure”
  • They always should be used with a “primary” procedure (parent) code
  • They should never be listed as a primary procedure
  • Payment for these services should not be lowered as a multiple-surgery reduction

A complete list of add-on codes may be found in CPT® Appendix D, “Summary of CPT Add-on Codes.

John Verhovshek
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John Verhovshek, MA, CPC, is a contributing editor at AAPC. He has been covering medical coding and billing, healthcare policy, and the business of medicine since 1999. He is an alumnus of York College of Pennsylvania and Clemson University.

No Responses to “Tips for Add-on Codes”

  1. Ruth says:

    I have a procedure that the provider did a bilateral laminectomy at C4-5, 5-6 and 6-7. We billed 63045 for the primary procedure and 63048 and another 63048 for the 2 additional levels. The claim is getting held up by an edit asking for a modifier for the two 63048 procedures because they were both on the same date of service. Add on codes should not need a modifier, correct?? 63045 is for unilateral or bilateral so the add on codes 63048 should inherently also be unilateral or bilateral, correct? Should we have billed 63048 with 2 units instead of 2 lines? I just can not figure out what is catching this. Thanks so much for your input.