# CARIN Blue Button Explained for Developers

CARIN Consumer Directed Payer Data Exchange, also called CARIN Blue Button, is a FHIR R4 implementation guide for sharing payer claims data with consumers. Flexpa's patient access documentation lists it alongside US Core for clinical data and SMART App Launch for authorization.

How it works: CARIN Blue Button -> FHIR R4 profiles -> Payer claims exchange. CARIN Blue Button describes consumer-directed payer data exchange.

## The guides that matter

| Guide | Covers |
|---|---|
| CARIN Blue Button | Claims and coverage from payers |
| US Core | Clinical data (USCDI) in FHIR R4 |
| SMART App Launch | OAuth 2.0-based authorization |

## Questions

**What is CARIN Blue Button?** CARIN Blue Button is the CARIN Consumer Directed Payer Data Exchange implementation guide. It defines FHIR R4 profiles for sharing payer claims data with consumers.

**Does Flexpa normalize payer differences?** Flexpa applies documented FHIR transforms to returned records and normalizes financial adjudication codes for supported payer endpoints. These transforms do not guarantee that every source supplies every field.

## More

- [Open-sourcing CARIN BB reference docs (blog)](https://www.flexpa.com/blog/open-sourcing-carin-bb-reference-documentation)
- [Patient access (docs)](https://www.flexpa.com/docs/consent/patient-access)
- [Understanding Flexpa's FHIR transforms (blog)](https://www.flexpa.com/blog/understanding-flexpas-fhir-transforms)

Last updated 2026-11-11.