All Resources

CPT for ENT: Utilizing Unlisted CPT Codes

CPT for ENT: Utilizing Unlisted CPT Codes

Q: When should I use an unlisted code?
A: An unlisted code should be used to report a procedure when no Category I or III CPT code exists to describe the procedure.

Q: When shouldn’t I use an unlisted code?
A: When a valid CPT code exists to describe the procedure. Unlisted codes should not be utilized as an attempt to obtain increased reimbursement in cases where a CPT code exists, but the reimbursement for the existing CPT code is low.

Q: Are there steps I should take to increase the likelihood my unlisted code will be paid?
A: Yes, best practices for using unlisted codes include, but are not limited to, the following:

  • Obtain prior authorization or certification for elective cases.
  • Learn what the carrier needs to process the unlisted code; many request the following: Submit your claim on a CMS 1500 claim form with an operative note and cover letter outlining how you are using the unlisted code and how you’ve selected your base code. Access the Academy’s  sample unlisted code cover letter here:
  • Select a base code that is SIMILAR to the procedure you performed. The code should represent surgery on the same area of the body and utilize a similar approach and exposure to the procedure you performed.
  • In your cover letter list 2-3 things that make the unlisted procedure more or less difficult than the comparator CPT code.
  • List the RVUs of the similar code to be sure it reflects a fair value for the work you have performed. If it does not, select a different base code.
  • Use your normal fee for the comparison code. Note that the payer will then adjust this up or down from their fee schedule, not your charge.

Q: Are there any other areas to be cautious about, or to avoid?
A: Yes, keep the following in mind when using unlisted codes:

  • As is the case with all claims, do not unbundle procedures that are included in a global surgery;
  • Do not use modifier 22 on unlisted procedure codes;
  • Do not report more than one unlisted procedure code per operative session;
  • Payment delays are likely, as the payer may perform a more detailed review of your claim when an unlisted code is submitted.
  • Make certain your documentation is fully supportive of the service and clearly describes the work performed, especially if it deserves a significantly higher reimbursement than the base code.

Revised October 2023
Published August 2013



Important Disclaimer Notice
CPT for ENT articles are a collaborative effort between the Academy’s team of CPT Advisors, members of the Physician Payment Policy (3P) workgroup, and health policy staff. Articles are developed to address common coding questions received by the health policy team, as well as to clarify coding changes and correct coding principles for frequently reported ENT procedures. These articles are not intended as legal, medical, or business advice and are not a guarantee of reimbursement. The information is also not meant to serve as the definitive or sole authority on billing and coding issues. The applicability of AAO-HNS billing and coding guidance for a particular procedure, must be determined by the responsible physician in light of all the circumstances presented by the individual patient. You should consult with your own advisors as well as Medicare or private carriers in making any decisions about how to bill and code particular services or procedures.
Save the Date for the AAO-HNSF 2024 Annual Meeting & OTO EXPOLearn More