{description: Codes to represent the drug tier of a particular medication in a health plan.  Base set are examples.  Each plan may have its own controlled vocabulary., package_name: hl7.fhir.us.davinci-drug-formulary, name: DrugTierCS, type: null, package_version: 1.2.0, class: unknown, kind: null, url: 'http://hl7.org/fhir/us/davinci-drug-formulary/CodeSystem/usdf-DrugTierCS', version: 1.2.0}