Public surface / Payer Patient Access APIs

CMS Blue Button 2.0 (Medicare)

This endpoint declares a solid public surface with minor gaps.

Current grade B

Reachability100

Capability transparency100

Interop readiness60

Observed surface

Base URL: https://api.bluebutton.cms.gov/v2/fhir
Category: Payer Patient Access APIs
Availability: answered 14 of the last 14 daily checks (100%)
Vantage agreement: reachable from all 3 vantages, which are 3 hosts on one network (github-actions): one network's view sampled 3 times, not 3 independent networks

Interpretation

A grade describes two public discovery documents at one point in time. It does not inspect patient data, authenticated behavior, or clinical quality.

Read the scoring method →

Findings

Reachability100

Pass: /metadata answers with HTTP 2xx over HTTPS: reachable from all 3 vantages, which are 3 hosts on one network (github-actions): one network's view sampled 3 times, not 3 independent networksR1 Spec ↗
Pass: /metadata responded in 557 ms (median across 3 reachable vantages on one network)R2 Spec ↗

Capability transparency100

Pass: fhirVersion declared: '4.0.1' (expected 4.x)T1 Spec ↗
Pass: software name and version declaredT2 Spec ↗
Pass: 3 resource types declared (narrow but fully documented)T3 Spec ↗
Pass: 3/3 declared resources document their interactionsT4 Spec ↗

Interop readiness60

Needs attention: 3 profile canonical(s) declared in rest.resource.profile, none of them US Core, CARIN, or Da Vinci; also checked rest.resource.supportedProfile, instantiates, imports, meta.profileI1 Spec ↗
Pass: SMART discovery document present and completeI2 Spec ↗
Pass: OAuth/SMART security service declared in CapabilityStatementI3 Spec ↗

Declared capability changes

2026-08-07: software_version: '2.259.0' -> '2.260.0'
2026-08-12: software_version: '2.260.0' -> '2.262.0'
2026-08-19: software_version: '2.262.0' -> '2.264.0'

Registry provenance

How this entry was verified

live CapabilityStatement fetch; publisher confirmed via implementation description 'gov.cms.bfd:bfd-server-war' and software 'Blue Button API' (recorded 2026-08-04). Re-checked 2026-08-19: live CapabilityStatement re-fetch from the davis-ca residential vantage; fhirVersion 4.0.1, 3 resource types, publisher 'Centers for Medicare & Medicaid Services', software 'Blue Button API: Direct 2.264.0'.

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This is an observational snapshot of a public, unauthenticated surface. It is not an audit, a ranking of care quality, or a statement about anyone's regulatory compliance. See how we grade.