HL7 version 2 messaging
We support HL7 v2 messaging through Care, retaining acknowledgements so your team can review the agreed interface and the responses returned by the receiving system.
Set by HL7 International
Subject type: technical format. HL7 version 2 is a messaging standard published by HL7 International. This page lists what Care builds and what activation needs.
What Care builds
- Messages follow HL7 v2.5.1 and travel over MLLP.
- Registration and updates (ADT A28, A04 and A08), admissions (A01) and discharges (A03).
- Appointments (SIU S12, S13, S15 and S26).
- Results (ORU R01) for laboratory, radiology and vital signs.
- Medication orders (OMP O09), dispenses (RDS O13) and administrations (RAS O17).
- Immunisations (VXU V04), problems (PPR PC1 to PC3) and referrals (REF I12 to I14).
- Acknowledgements (AA accepted, AE error, AR rejected) are read and stored with the message.
Direction, transport and versions
Messages go from Care to a health information exchange over MLLP. This page covers those outbound messages. Inbound HL7 interfaces, such as one from a laboratory analyser, are scoped separately. Version 2.5.1 is the version built, so any other version is a scoping question. No universal interface compatibility or automatic acceptance is claimed.
Responsibilities and activation
NextHealth builds the messages, configures the transport and retries a failed message a limited number of times. Your facility completes the exchange’s onboarding, which can include agreements, ports, address allow-listing and a provider code. The exchange provides test access, representative messages are tested, and the exchange decides when a facility goes live. A test mode records the message and a placeholder acknowledgement until then.
Illustrative example: an accepted message and a rejected one
This example uses synthetic data. Care sends a registration message (ADT A28) for a synthetic patient. The receiving system returns an acknowledgement with code AA, and Care stores the message and the acknowledgement and marks the exchange acknowledged. In a second case, a synthetic result message comes back with AE or AR. The exchange record shows the error or rejection and is not marked acknowledged, so the team investigates with the exchange before sending it again.
Official source
HL7 International. HL7 publishes the version 2 standard and its product briefs.
What we claim, precisely
The system holds the evidence; the facility's accountable person attests. Nothing here asserts that a facility is compliant.
Common questions
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No. Each interface needs agreement on message types, fields, receiving requirements and testing. A general messaging capability is not evidence that a particular system connection is already configured.
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Care builds version 2.5.1 messages over MLLP: registration, admission and discharge, appointments, results, medication, immunisation, problem and referral messages. Another version, or a message not listed here, is a scoping question.
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Care stores the acknowledgement. An accepted message is marked acknowledged. An error or a rejection is not, and the team investigates with the exchange. What each error means is agreed with the exchange during testing.
Not answered here? Contact the team
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