This is the way the EHR is designed. We have “billing” data (CPT4 codes) and “encounter” data (giant, unwieldy, ambiguous tables to run the business of seeing patients). Two separate things that aren’t linked. It’s messy stuff. And we do our best to de-duplicate or merge all that we can, but sometimes it’s not possible. Visits are especially hard because the EHR contains many visits which are not patient-provider interactions and there is not a reliable flag. Every time someone at the healthcare system enters something into a person’s electronic chart, it must be linked to an encounter in the person’s chart. And if there isn’t an appropriate encounter to link, then an encounter is created. A person fills out a document, encounter record created. MRI is faxed over from another institution, another encounter. Labs reviewed by the RN, another encounter. Different domains within the EHR differ in granularity and ability to establish a link between billing and encounter data. Messy stuff we can discuss over a beer, or two, possibly 3 beers because it’s a long conversation 
Messy EHR data aside, I’m still arguing for inclusion on these CPT4 codes in the Observation table. Since these are observations: