This is the ValueSet that contains all the codes in Procedure Modifier Codes - AMA CPT - CMS HCPCS Value Set (http://hl7.org/fhir/us/carin-bb/ValueSet/AMACPTCMSHCPCSModifiers) and Procedure Modifier Codes - AMA CPT - CMS HCPCS Value Set (http://hl7.org/fhir/us/carin-bb/ValueSet/AMACPTCMSHCPCSModifiers). E.g. what you have to deal with if you get resources containing codes in either of them