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 58 of the last 58 daily checks (100%)
Last answered: 2026-10-03 (answered on this run)
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

What each vantage saw

reached from 3 of 3 reporting vantages, on 1 network
Vantage	Result	What it saw	Condition
`github-actions/macos-latest`	reached	answered in 376 ms	HTTP 200
`github-actions/ubuntu-latest`	reached	answered in 306 ms	HTTP 200
`github-actions/windows-latest`	reached	answered in 1000 ms	HTTP 200

Vantages on one network are one network’s view sampled several times. A rule applied to that network’s address space reaches every one of them at once and reads exactly like agreement.

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 →

This endpoint's full report: what was observed, what was not, and what would change it →

What its CapabilityStatement declares, resource by resource →

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 376 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'
2026-08-28: software_version: '2.264.0' -> '2.265.0'
2026-08-29: software_version: '2.265.0' -> '2.266.0'
2026-09-04: software_version: '2.266.0' -> '2.267.0'
2026-09-11: software_version: '2.267.0' -> '2.268.0'
2026-09-22: software_version: '2.268.0' -> '2.269.0'
2026-09-29: software_version: '2.269.0' -> '2.270.0'
2026-09-30: software_version: '2.270.0' -> '2.271.0'
2026-10-01: software_version: '2.271.0' -> '2.272.0'

Declared app-to-server access

What the endpoint's own documents declare about app-to-server access, observed on this run. Nothing here was requested or exercised, and none of it is graded. An absent field is reported as absent, not as a refusal: a document that does not mention a field has not said anything about it.

What the SMART discovery document and the CapabilityStatement declare about SMART Backend Services and Bulk Data
Question	Answer	What the document says	Where it is declared
Declares private_key_jwt client authentication at the token endpoint	not declared: the field is absent	the document has no token_endpoint_auth_methods_supported	SMART discovery: token_endpoint_auth_methods_supported
Declares the client_credentials grant, which SMART Backend Services uses	not listed	grant_types_supported lists 1 and not client_credentials	SMART discovery: grant_types_supported
Declares the client-confidential-asymmetric capability	not listed	capabilities lists 8 and not client-confidential-asymmetric	SMART discovery: capabilities
Declares system-level scopes	not listed	none of 9 scopes_supported is a system/ scope	SMART discovery: scopes_supported
Declares an export operation	not listed	0 operations are declared and none is named export	CapabilityStatement: rest.operation and rest.resource.operation
Instantiates the Bulk Data Access implementation guide	not listed	0 canonicals are instantiated and none is Bulk Data's	CapabilityStatement: instantiates

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.

Every observation on record for this endpoint, with the dates it answered and the dates it did not.