Arizona's Statewide HIE, "The Network", Explained
A plain-language explainer of what a statewide health information exchange is, who takes part, how directed and query-based exchange differ, and why the master patient index is the quiet workhorse that makes any of it safe.
What a statewide HIE actually is
Shared infrastructure, not a single database
A health information exchange (HIE) is the shared infrastructure that lets unaffiliated organizations locate, request and share a patient's clinical information electronically. A statewide HIE extends that reach across an entire state, so a record created in one community is reachable when the same patient is treated somewhere else. It is best understood as connective tissue between many systems rather than as one giant database that owns the data.
The Office of the National Coordinator for Health IT (ONC) frames exchange around two complementary modes, described below. A neutral statewide exchange supports both.
Two modes of exchange
Most real-world care needs both. They answer different clinical questions.
Directed exchange (push)
The sender initiates: a referral, a discharge summary, or a lab result is pushed straight to a known recipient. Often automated and used to coordinate planned transitions of care.
Read moreQuery-based exchange (pull)
A clinician searches for and retrieves records other providers have made available. Essential for unplanned and emergency care, where the treating team does not already hold the history.
Read moreThe master patient index (MPI)
An exchange is only as trustworthy as its ability to know that two records describe the same person. The master patient index is the component that resolves identity across many source systems — reconciling names, dates of birth, addresses and identifiers so that a query returns one patient's history, not a stranger's. Get the MPI wrong and you risk either a fragmented record or, far worse, a wrong-patient match. It is foundational, not optional.
Frequently asked questions
01Does the HIE own my medical records?
No. The exchange is infrastructure that helps authorized providers find and share information held in their own systems. Participation, access and consent are governed by policy and by law — see our consent and data-sharing explainer.
02What is the difference between an HIE and an EHR?
An electronic health record (EHR) is the system a single organization uses to document care. An HIE is the connective layer between many organizations' systems, so a record can travel beyond the walls where it was created.
03Why does a neutral, statewide exchange matter?
Because patients cross organizational and vendor boundaries. A neutral statewide exchange means continuity of care does not depend on whether two providers happen to use the same EHR vendor.
Keep going
Next, see exactly how a record travels from one provider to another across the exchange.