CMS Blue Button 2.0 website screenshot

CMS Blue Button 2.0

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.

CMS Blue Button 2.0 publishes 5 APIs on the APIs.io network, including Coverage API, ExplanationOfBenefit API, Metadata API, and 2 more. Tagged areas include Blue Button, CARIN, Medicare, FHIR, and Claims Data.

CMS Blue Button 2.0’s developer surface includes authentication, documentation, sandbox, getting-started guide, and 8 more developer resources.

41.9/100 developing ▬ flat Agent 29/100 agent ready Full breakdown ↓
scored 2026-08-24 · rubric v0.13.0
AccessFreemiumSelf serve⚡ Free to try
5 APIs
Blue ButtonCARINMedicareFHIRClaims DataPatient AccessHealthcareGovernment

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-24 · rubric v0.13.0
Composite quality — 41.9/100 · developing
Contract Quality 11.7 / 21
Developer Ergonomics 6.9 / 17
Access Clarity 6.7 / 17
Operational Transparency 3.8 / 11
Contract Governance 0.0 / 10
Discoverability 6.3 / 9
Regulatory Posture 3.0 / 15
Agent readiness — 29/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
Documented Reversibility 6 / 6
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 4 / 4
Regulatory Posture applies to this provider. Its tags matched the Health regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/cms-blue-button: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 5

Individual APIs this provider publishes, each with its own machine-readable definition.

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.

Open Collections 7

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

CMS Blue Button 2.0 API

OPEN COLLECTION

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Rate Limits 1

Documented rate limits and quota policies.

Cms Blue Button Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Cms Blue Button Authentication

oauth2 · 1 scheme

SECURITY

Cms Blue Button Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Cms Blue Button Agentic Access

8 operations

8 operations · 0 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Documentation 1

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 1

The organization behind the API

Source (apis.yml)

apis.yml Raw ↑
aid: cms-blue-button
url: https://raw.githubusercontent.com/api-evangelist/cms-blue-button/refs/heads/main/apis.yml
name: CMS Blue Button 2.0
kind: government
description: 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.
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/cms-blue-button.png
tags:
- Blue Button
- CARIN
- Medicare
- FHIR
- Claims Data
- Patient Access
- Healthcare
- Government
created: '2026-07-11'
modified: '2026-07-11'
specificationVersion: '0.23'
apis:
- aid: cms-blue-button:cms-blue-button-coverage-api
  name: CMS Blue Button 2.0 Coverage API
  description: Medicare coverage resources, one per coverage type.
  humanURL: https://bluebutton.cms.gov/api-documentation/calling-the-api/
  baseURL: https://api.bluebutton.cms.gov/v2/fhir
  tags:
  - Coverage
  properties:
  - type: OpenAPI
    url: openapi/cms-blue-button-coverage-api-openapi.yml
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/
  - type: APIReference
    url: https://bluebutton.cms.gov/data/understanding-the-data/
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/authorization/
- aid: cms-blue-button:cms-blue-button-explanationofbenefit-api
  name: CMS Blue Button 2.0 ExplanationOfBenefit API
  description: Medicare Parts A, B, and D claims as CARIN Blue Button EOB profiles.
  humanURL: https://bluebutton.cms.gov/api-documentation/calling-the-api/
  baseURL: https://api.bluebutton.cms.gov/v2/fhir
  tags:
  - ExplanationOfBenefit
  properties:
  - type: OpenAPI
    url: openapi/cms-blue-button-explanationofbenefit-api-openapi.yml
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/
  - type: APIReference
    url: https://bluebutton.cms.gov/data/understanding-the-data/
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/authorization/
- aid: cms-blue-button:cms-blue-button-metadata-api
  name: CMS Blue Button 2.0 Metadata API
  description: FHIR capability statement.
  humanURL: https://bluebutton.cms.gov/api-documentation/calling-the-api/
  baseURL: https://api.bluebutton.cms.gov/v2/fhir
  tags:
  - Metadata
  properties:
  - type: OpenAPI
    url: openapi/cms-blue-button-metadata-api-openapi.yml
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/
  - type: APIReference
    url: https://bluebutton.cms.gov/data/understanding-the-data/
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/authorization/
- aid: cms-blue-button:cms-blue-button-patient-api
  name: CMS Blue Button 2.0 Patient API
  description: Beneficiary demographic and administrative data.
  humanURL: https://bluebutton.cms.gov/api-documentation/calling-the-api/
  baseURL: https://api.bluebutton.cms.gov/v2/fhir
  tags:
  - Patient
  properties:
  - type: OpenAPI
    url: openapi/cms-blue-button-patient-api-openapi.yml
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/
  - type: APIReference
    url: https://bluebutton.cms.gov/data/understanding-the-data/
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/authorization/
- aid: cms-blue-button:cms-blue-button-userinfo-api
  name: CMS Blue Button 2.0 UserInfo API
  description: OpenID Connect userinfo for the authorizing beneficiary.
  humanURL: https://bluebutton.cms.gov/api-documentation/calling-the-api/
  baseURL: https://api.bluebutton.cms.gov/v2/fhir
  tags:
  - UserInfo
  properties:
  - type: OpenAPI
    url: openapi/cms-blue-button-userinfo-api-openapi.yml
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/
  - type: APIReference
    url: https://bluebutton.cms.gov/data/understanding-the-data/
  - type: Documentation
    url: https://bluebutton.cms.gov/api-documentation/authorization/
common:
- type: AgenticAccess
  url: agentic-access/cms-blue-button-agentic-access.yml
- type: DomainSecurity
  url: security/cms-blue-button-domain-security.yml
- type: Authentication
  url: authentication/cms-blue-button-authentication.yml
- type: Website
  url: https://bluebutton.cms.gov
- type: Documentation
  url: https://bluebutton.cms.gov/api-documentation/
- type: GitHubOrganization
  url: https://github.com/CMSgov
- type: Sandbox
  url: https://sandbox.bluebutton.cms.gov
- type: GettingStarted
  url: https://bluebutton.cms.gov/production-access/
- type: TermsOfService
  url: https://bluebutton.cms.gov/terms/
- type: Plans
  url: plans/cms-blue-button-plans-pricing.yml
- type: RateLimits
  url: rate-limits/cms-blue-button-rate-limits.yml
- type: FinOps
  url: finops/cms-blue-button-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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