Health Samurai Blog

FHIR has no $unmerge operation. We built one that reverses a merge using Provenance + History API and lets the client decide what to do with data added between the merge and unmerge.

We analyzed 7 million records in the NPI Registry and found thousands of providers with multiple NPIs. Explore the duplicates yourself with our interactive tool.

FHIR's Patient/$merge assumes the server knows how to merge. Two decades of MPI vendor configs, EHR vendor divergence, and national registry policy show why one algorithm cannot serve every organization.

How duplicate patient records silently corrupt healthcare analytics — inflating population metrics, fragmenting clinical histories, skewing cohort construction, and biasing ML models — and why identity resolution upstream is the structural fix.

FHIR R5's Patient/$merge is a start, but production MDM needs more. We built a resource-agnostic $merge with client-driven plans, atomic audit trails, and a generic $referencing operation.