Chiming in here, since I have a related post where the re-classification of CPT codes from Procedure to Visit caused our ETL and an ongoing health equity analysis to break.
We don’t use HCPCS or CPT codes to create visits, since we have EHR data that provides an easier ETL path to create visit_occurrence and visit_detail.
However, we do use CPT E&M codes in some of our analyses. For example, we are studying potential delay in diagnosis and referral of patients with CKD (based upon GFR values), and one of the outcome cohorts is new patient office visits to nephrologists. We use the CPT codes 99202-99205 to identify new patient visits (rather than using the first visit to a nephrologist with a long preceding clean period). We have also been planning other analyses of treatment variability where we needed easy access to CPT codes within Atlas cohorts.
The January changes to the vocabulary stack caused our ETL to delete all such E&M codes, so we had to revert to and older vocabulary stack; and I haven’t seen clarity from the community yet on where E&M codes should live (Observations, Procedures, other?) so that we can include them in Atlas cohorts in the new environment since the January '23 vocabulary release.