# CMS Blue Button 2.0

**Canonical:** https://apis.io/providers/cms-blue-button/  
**Website:** https://bluebutton.cms.gov  
**APIs profiled:** 5

Blue Button 2.0 is the Centers for Medicare & Medicaid Services (CMS) API that lets Medicare beneficiaries share their Parts A, B, and D claims data with applications they trust. It is a FHIR R4 API conforming to the CARIN Blue Button Implementation Guide (CARIN Consumer Directed Payer Data Exchange), serving ExplanationOfBenefit, Patient, and Coverage resources for 60+ million people with Medicare. Access is patient-facing - each beneficiary authorizes an app through an OAuth 2.0 authorization-code flow (with mandatory PKCE) on Medicare.gov, choosing whether to share demographic data. A self-serve sandbox with synthetic enrollee data is open to everyone; production credentials are free but require CMS approval of the application.

## Kin Score — 41.9 / 100 (developing)

Scored 2026-08-24 under rubric 0.13.0. Trend: flat (-0.4 from 42.3).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 55.2 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 34.2 |
| Developer Ergonomics | 40.5 |
| Commercial Clarity | 39.5 |
| Access Clarity | 39.5 |

Regulatory layer — **Health**: 20.0 (matched via tags).

## Agent readiness — 28.7 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | na |
| MCP Server | no |
| Auth Clarity | negotiable |
| Idempotency | na |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | na |
| Delegated Identity | documented |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Access

Freemium · Self-serve signup — onboarding: self-serve, pricing: freemium, trial: no (confidence: high).

## APIs (5)

- **CMS Blue Button 2.0 Coverage API** — Medicare coverage resources, one per coverage type.
- **CMS Blue Button 2.0 ExplanationOfBenefit API** — Medicare Parts A, B, and D claims as CARIN Blue Button EOB profiles.
- **CMS Blue Button 2.0 Metadata API** — FHIR capability statement.
- **CMS Blue Button 2.0 Patient API** — Beneficiary demographic and administrative data.
- **CMS Blue Button 2.0 UserInfo API** — OpenID Connect userinfo for the authorizing beneficiary.

## Agentic access (1)

- **Cms Blue Button Agentic Access** — 8 operations

## Security (2)

- **Cms Blue Button Authentication** — oauth2 · 1 scheme
- **Cms Blue Button Domain Security** — TLSv1.3 · HSTS · DNSSEC · DMARC

## Plans (1)

- **Cms Blue Button Plans Pricing**

## Tags

Blue Button, CARIN, Medicare, FHIR, Claims Data, Patient Access, Healthcare, Government

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/cms-blue-button/). Scores are computed from the provider's own public artifacts under a published rubric.