POST /Measure/{id}/$evaluate-measure with reportType=subject-list and a Group subject reference covering the target population, along with periodStart and periodEnd
Receive a MeasureReport of type 'subject-list'; each group.population element includes a subjectResults reference to a contained List resource
Dereference the contained List resources to obtain Patient references for each population stratum (initial-population, denominator, numerator, exclusions)
Use the patient lists to drive downstream workflows such as gap notifications or supplemental data collection
Confirm that the server's CapabilityStatement advertises support for the subject-list reportType before invoking, as it is optional in the DEQM IG
Known gotchas
subject-list MeasureReports can be very large when population sizes are high; servers may cap response size or time out — consider paginating via Group-level Bulk Data export instead for large cohorts
Contained List resources inside the MeasureReport are transient and not independently retrievable by ID; copy patient references out before discarding the MeasureReport
Not all FHIR servers implement subject-list; a server may return 501 Not Implemented or silently fall back to population type — check measureReport.type in the response
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