How Patient Records Move Between Providers
Behind a simple click — "pull this patient's history" — sits a chain of message standards, document formats and identity checks. Here is how a record actually travels across the exchange, step by step.
The languages records are written in
Three standards do most of the work
Clinical information moves in well-defined formats so that a system that did not create the data can still read it. HL7 v2 messages — such as ADT (admit, discharge, transfer) and ORU (observation results, e.g. lab values) — carry real-time events and results. C-CDA (Consolidated Clinical Document Architecture) packages a care summary as a structured document. FHIR (Fast Healthcare Interoperability Resources) exposes the same kinds of data through modern RESTful web APIs (JSON or XML over HTTP). Many organizations run HL7 v2 for internal real-time workflows and FHIR for external API access at the same time.
A record's journey, end to end
From an event at one provider to a usable record in front of another clinician.
1. An event is generated
A patient is admitted, a lab result is finalized, or a visit summary is produced. The source system emits an HL7 v2 message (ADT for the encounter, ORU for results) or assembles a C-CDA document.
2. Identity is resolved
The exchange's master patient index (MPI) matches the incoming data to the correct person, reconciling demographics across systems so the record attaches to one patient — not a near-duplicate.
3. Push or pull is determined
In directed exchange the information is pushed to a known recipient (a referral or discharge summary). In query-based exchange the data is held available so another provider can pull it when needed.
4. A clinician queries or receives
At the point of care, a provider either receives the pushed document or queries the exchange. A FHIR API or document query returns the available records the patient's other providers have shared.
5. The record is rendered in context
The receiving system presents the history — prior diagnoses, medications, allergies, recent results — alongside the clinician's own data, supporting reconciliation rather than a blind start.
Standards are what make the data portable
None of this works if every system speaks its own dialect. Shared standards — HL7 v2, C-CDA and FHIR — are the reason a record created in one EHR is legible in another. They are the load-bearing layer of every claim about "connected care." When the standard is followed and identity is resolved correctly, exchange reduces duplicate testing and supports safer medication reconciliation.
How is access controlled?
Moving a record safely depends on consent. See how opt-in, opt-out and sensitive-data rules govern who can pull what.