Determine the capability of the receiving public health agency or intermediary — many agencies and routing platforms (such as the AIMS platform used in the U.S.) accept CDA eICR today, while FHIR-based eCR is being phased in; verify the current accepted formats with the receiving entity.
Use CDA eICR when your trading partner or the jurisdiction mandates CDA-based reporting, or when your EHR natively generates CDA documents and the public health routing infrastructure is CDA-centric.
Use FHIR eCR (per the HL7 eCR FHIR IG) when your environment is FHIR-native, the receiving infrastructure supports FHIR document exchange, or when regulatory or IG requirements specify FHIR.
Review the eCR FHIR IG to understand the mapping between CDA eICR sections/entries and FHIR Composition sections/resources, as the two standards carry equivalent clinical content through different syntaxes.
Consider the EHR's native export capability — many certified EHRs generate CDA eICR as part of ONC certification requirements; a FHIR translation layer may be needed if downstream systems require FHIR.
Monitor HL7, the CDC eCR program, and jurisdiction-specific guidance for the transition timeline from CDA to FHIR eCR, as requirements are evolving.
Known gotchas
Assuming universal FHIR eCR support at public health agencies is premature — confirm receiver capability before committing to FHIR-only submission.
CDA and FHIR eICR are not byte-for-byte equivalent; clinical content mappings between the two formats require careful validation to avoid data loss.
Some routing intermediaries accept one format and transcode to the other — understand whether transcoding occurs and what fidelity is maintained.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp