Review the CARIN BB IG (hl7.org/fhir/us/carin-bb) to locate the ExplanationOfBenefit Inpatient Institutional profile and understand its base constraints on the base FHIR EOB resource.
Populate required slices on EOB.type using codes from the X12 claim type value set and set the inpatient institutional category slice on EOB.item or EOB.adjudication as required by the profile.
Map UB-04 revenue codes to EOB.item.revenue, procedure codes (ICD procedure) to EOB.procedure, and diagnosis codes to EOB.diagnosis with appropriate type slices (principal, admitting, other).
Populate EOB.hospitalization with admission and discharge dates, set EOB.patient to a reference to a CARIN BB Patient profile, and set EOB.insurance referencing a CARIN BB Coverage.
Validate the resource using the FHIR $validate operation against the CARIN BB Inpatient Institutional profile canonical URL and resolve any must-support element failures.
Confirm the EOB is accessible via the Patient Access API endpoint with appropriate SMART on FHIR scopes (patient/ExplanationOfBenefit.read) and appears in the member's $everything or search results.
Known gotchas
The CARIN BB IG defines multiple EOB profiles (inpatient, outpatient, professional, pharmacy, oral) distinguished by EOB.type coding — using the wrong type code will fail profile validation even if all other elements are correct.
Revenue codes on EOB.item.revenue and DRG codes on EOB.supportingInfo must reference specific value sets defined in CARIN BB; generic FHIR code systems are not sufficient.
Must-support obligations in CARIN BB are layered on top of US Core — implementers must handle both layers; the IG distinguishes between 'mandatory' (1..* or cardinality) and 'must support' (which requires returning the element if known).
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