Related Terms

FHIR

Healthcare interoperability

 

See Also

HL7 feeds are one of the ways outside tools connect to a practice's records. See how EMR integrations work in practice.

EMR Integration

ABOUT THIS ENTRY

Category Core: EMR/EHR

Reading time: 1 min

Updated: Oct 2026

HL7

Definition

HL7 (Health Level Seven) is a set of international standards that sets how healthcare systems format and send clinical and admin data to each other, such as lab results, orders, and appointment updates.

Why the distinction matters

Health Level Seven International, a standards group founded in 1987, publishes HL7. The "Seven" refers to the seventh layer of the OSI network model, the application layer, where software trades data.

Most people who say HL7 mean HL7 version 2. It's the workhorse behind hospital and lab feeds: short, pipe-separated text messages sent over an interface. Each message has a type. ADT messages carry patient registration and visit events, ORU messages carry results, and SIU messages carry scheduling changes. If your EHR, lab, or imaging center has a live interface, there's a good chance HL7 v2 is on the wire.

Example

A patient books a follow-up at the front desk. The practice management system sends an SIU message saying the slot is filled. A connected reminder tool reads that message and queues a text for two days before the visit, with no one copying the date by hand.

Frequently Asked

  • Is HL7 the same as FHIR?

    They come from the same organization. FHIR is HL7's newer standard, built on web APIs, while HL7 v2 sends message files over a set interface. Many practices use both.

  • Is HL7 still used?

    Yes. HL7 v2 still runs a large share of lab, hospital, and scheduling interfaces today.

  • Does my practice need to know HL7 to connect software?

    Usually not. Your EHR vendor and the software vendor set up the interface. You'll mainly need to approve the connection and confirm which data flows each way.