HIE stands for health information exchange, the system that allows doctors, nurses, pharmacists, and other providers to electronically access and share a patient’s medical information across different organizations. Rather than relying on faxes, phone calls, or patients carrying paper records between appointments, HIE moves vital data like lab results, medication lists, and discharge summaries through secure digital channels. As of 2025, 96% of U.S. hospitals electronically send care records and 93% receive them, making HIE one of the most widely adopted tools in modern healthcare.
How HIE Works in Practice
At its simplest, health information exchange solves a coordination problem. Your primary care doctor, your specialist, your local emergency room, and your pharmacy may all use different electronic health record systems that don’t naturally talk to each other. HIE bridges those gaps so that when you show up at an urgent care clinic in another city, the provider there can pull up your allergy list, current medications, and recent test results instead of starting from scratch.
There are three main forms of HIE, each serving a different clinical need:
- Directed exchange works like secure email for medical data. One provider sends a specific document, such as a referral note, lab order, or discharge summary, directly to another provider. This is the digital replacement for faxing and mailing records, and it’s commonly used during care transitions when you’re referred to a specialist or discharged from a hospital.
- Query-based exchange lets a provider search for and request your records from other organizations. This is especially useful in unplanned care. If you arrive at an emergency room unconscious, the ER team can query connected systems to find your medical history, spot medication conflicts, and avoid repeating tests you’ve already had.
- Consumer-mediated exchange puts you in control of your own data. Through patient portals and health apps, you can view your records, add information, and share data with providers of your choosing. About one in five patient portal users transmitted their health data to an outside provider or app in 2020, a seven-percentage-point increase from just three years earlier.
The Technology Behind It
For HIE to work, different electronic health record systems need a common language. That’s where standards like FHIR come in. Developed by the standards organization Health Level 7, FHIR (Fast Healthcare Interoperability Resources) is an application programming interface that defines how health data is structured and exchanged. Think of it as a universal translator: it breaks a patient’s record into modular building blocks called “resources,” each representing a specific type of data like a medication, a lab result, or a diagnosis. Because FHIR is built on the same web technology that powers everyday apps, it lets developers create tools that can read and write health data across otherwise incompatible systems.
Federal rules finalized in 2020 under the 21st Century Cures Act now require certified health IT developers to adopt these standards-based interfaces. The goal is to prevent “information blocking,” where organizations deliberately make it hard to share data, and to ensure patients can access their records through smartphone apps of their choice.
How Providers Connect
Most health information exchange happens through regional, state, or national networks. These organizations act as intermediaries, connecting hospitals, clinics, labs, and pharmacies within a geographic area or across the country. At the federal level, a framework called TEFCA (Trusted Exchange Framework and Common Agreement) is building a nationwide network of networks. The Office of the National Coordinator for Health IT has designated seven Qualified Health Information Networks under TEFCA so far, including CommonWell Health Alliance and Kno2, with the list expected to grow.
Hospital adoption has climbed steadily. In 2025, 94% of U.S. hospitals could electronically search for patient information held by other organizations, and 79% could integrate outside records directly into their own systems. The share of hospitals engaged in all four interoperability domains (sending, receiving, finding, and integrating records) reached 76%.
Clinical and Financial Benefits
The most tangible benefit of HIE is reducing redundant care. When an emergency physician can see that you had a CT scan two days ago at another hospital, there’s no reason to order a second one. Studies in Indianapolis and Milwaukee found average savings of $26 to $29 per emergency department visit when clinicians queried an HIE during care. In Memphis, HIE use in emergency departments generated roughly $1.1 million in community-wide savings, with 97.6% of those savings coming from avoided hospital admissions. One health plan reported a direct return on investment of more than 2:1.
Beyond cost savings, query-based exchange helps providers catch medication discrepancies. When your records are aggregated from multiple sources into a single view, a pharmacist or doctor can spot conflicting prescriptions or dangerous drug interactions that would be invisible if each provider only saw their own slice of your history. Directed exchange, meanwhile, speeds up referrals and care transitions. Instead of waiting days for a faxed discharge summary, your follow-up provider can receive a structured care document within minutes.
Privacy and Your Consent
How your data enters an HIE depends on where you live. States use one of two consent models. In opt-out states like Alabama and Arkansas, your records are automatically included in the exchange, but you can request removal at any time. Providers in these states are responsible for informing you of your right to opt out and documenting your decision. If you haven’t opted out, participating providers can assume your information is available.
In opt-in states like California, New York, and Massachusetts, your records aren’t shared through the HIE unless you provide written authorization. New York, for example, requires a signed consent before any qualified entity can give a participating provider access to your information. Nevada similarly requires that consent be obtained before retrieving records from an exchange. The opt-in model gives patients more direct control, though it can mean providers have less complete information available during unexpected visits.
Regardless of the model, HIE data is protected under federal privacy rules. Only authorized providers involved in your care can access your information, and the exchange itself uses encryption and identity verification to prevent unauthorized access.
Barriers That Still Exist
Despite high adoption numbers, HIE isn’t seamless everywhere. The most commonly cited problems among providers are incomplete information, disrupted workflows, and exchanged records that don’t meet their clinical needs. Practically, this can look like a provider logging into a separate portal with a different password, scrolling through pages of data that aren’t organized in a useful way, and ultimately finding the record they need is missing entirely.
Patient matching remains a persistent technical challenge. Without a universal patient identifier in the U.S., systems rely on name, date of birth, and other demographic details to link records to the right person. Misspellings, name changes, and inconsistent data entry can cause mismatches. Competition between health systems also plays a role. Some hospitals remain hesitant to share data with rival organizations out of concern that easier data flow could lead patients to seek care elsewhere. And while the gap between sending and integrating data is narrowing, 79% integration versus 96% sending shows that receiving a record and actually making it useful inside a provider’s workflow are two different things.