The American Medical Association (AMA) added a new CPT® appendix, effective April 1, 2022. The appendix lists codes you may use to report audio-only services with modifier 93 (Synchronous Telemedicine Service Rendered Via Telephone or Other Real-Time Interactive Audio-Only Telecommunications System) appended.
On Codify by AAPC, you will find this information in Appendix U: CPT® Codes That May Be Used for Synchronous Real-Time Interactive Audio-Only Telemedicine Services. Look for appendices on the left menu of the Codify by AAPC home page or the search results page under Coding/CPT®/Appendices.