openapi: 3.1.0
info:
  title: Cigna Drug Formulary Bulk Data MedicationKnowledge API
  description: Public FHIR-based Drug Formulary API exposing Cigna's covered drug lists, formulary tiers, prior authorization, step therapy, and quantity limits. Implements the HL7 Da Vinci PDex US Drug Formulary IG required by the CMS Interoperability and Patient Access rule.
  version: '1.0'
  contact:
    name: Cigna Developer Support
    url: https://developer.cigna.com/support
servers:
- url: https://fhir.cigna.com/DrugFormulary/v1
  description: Cigna Drug Formulary Production
tags:
- name: MedicationKnowledge
paths:
  /MedicationKnowledge:
    get:
      operationId: searchMedicationKnowledge
      summary: Search covered drugs and formulary tier, step therapy, and prior auth
      tags:
      - MedicationKnowledge
      parameters:
      - name: code
        in: query
        schema:
          type: string
        description: RxNorm or NDC code
      - name: DrugPlan
        in: query
        schema:
          type: string
        description: InsurancePlan id of the formulary
      responses:
        '200':
          description: FHIR Bundle of MedicationKnowledge resources
externalDocs:
  description: Cigna Service APIs
  url: https://developer.cigna.com/docs/service-apis