openapi: 3.1.0
info:
  title: Cigna Drug Formulary Bulk Data Observation 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: Observation
paths:
  /Observation:
    get:
      operationId: searchObservation
      summary: Retrieve clinical observations for the authenticated member
      tags:
      - Observation
      responses:
        '200':
          description: FHIR Bundle of Observation resources
externalDocs:
  description: Cigna Service APIs
  url: https://developer.cigna.com/docs/service-apis