http://hl7.org/fhir/us/core/StructureDefinition/us-core-encounter

http://hl7.org/fhir/us/core/ValueSet-us-core-encounter-type.html#us-core-encounter-type

What is included is: Include all codes defined in http://www.ama-assn.org/go/cpt

Is the intent to only allow the codes from the selected section for the CURRENT year to be used? Or would it need to be the codes from the selected section for the Date of Service (or begin date of service) being represented to be used. If all years, Please see:  http://hl7.org/fhir/R4/cpt.html

Per 4.3.9.6 Implicit Value Sets 

The value set URL http://hl7.org/fhir/ValueSet/cpt-all is a value set that includes all CPT codes.