openapi: 3.1.0
info:
  title: Cigna Drug Formulary 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
externalDocs:
  description: Cigna Service APIs
  url: https://developer.cigna.com/docs/service-apis
servers:
  - url: https://fhir.cigna.com/DrugFormulary/v1
    description: Cigna Drug Formulary Production
tags:
  - name: InsurancePlan
  - name: MedicationKnowledge
  - name: Basic
paths:
  /metadata:
    get:
      operationId: getCapabilityStatement
      summary: Retrieve the FHIR capability statement
      tags: [InsurancePlan]
      responses:
        '200':
          description: FHIR CapabilityStatement
  /InsurancePlan:
    get:
      operationId: searchFormularyPlan
      summary: List drug formulary plans offered by Cigna
      tags: [InsurancePlan]
      parameters:
        - name: status
          in: query
          schema:
            type: string
      responses:
        '200':
          description: FHIR Bundle of InsurancePlan formulary resources
  /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