HL7v2 Message Types
A reference directory of common HL7 version 2 message types. Each page explains the trigger event, when the message is sent, its key segments, and includes a realistic example plus one-click links to validate the message and map it to FHIR.
ADT messages
- ADT^A01 - Admit / Visit Notification
- ADT^A02 - Transfer Patient
- ADT^A03 - Discharge / End Visit
- ADT^A04 - Register a Patient
- ADT^A05 - Pre-admit a Patient
- ADT^A08 - Update Patient Information
- ADT^A11 - Cancel Admit
- ADT^A28 - Add Person Information
- ADT^A31 - Update Person Information
- ADT^A06 - Change an Outpatient to an Inpatient
- ADT^A12 - Cancel Transfer
- ADT^A13 - Cancel Discharge
- ADT^A34 - Merge patient information - patient id only
- ADT^A40 - Merge Patient - Patient Identifier List
- ADT^A44 - Move Account Information - Patient Account Number
- ADT^A60 - ADT Message
ORU messages
SIU messages
VXU messages
- VXU^V04 - Unsolicited Vaccination Record Update
MDM messages
ORM messages
- ORM^O01 - General Order Message
RDE messages
- RDE^O11 - Pharmacy/Treatment Encoded Order
OML messages
- OML^O21 - Laboratory Order Message
ORL messages
- ORL^O22 - General Laboratory Order Acknowledgment Message
RDS messages
- RDS^O13 - Pharmacy/Treatment Dispense Message
RAS messages
- RAS^O17 - Pharmacy/Treatment Administration
RGV messages
- RGV^O15 - Pharmacy/Treatment Give
SRM messages
- SRM^S01 - Request New Appointment Booking
SRR messages
- SRR^S01 - Response to New Appointment Booking Request
VXQ messages
- VXQ^V01 - Query for vaccination record
DFT messages
- DFT^P03 - Detail Financial Transaction
BAR messages
MFN messages
QRY messages
- QRY^A19 - Patient query
ADR messages
- ADR^A19 - Patient query
QBP messages
- QBP^Q11 - Query By Parameter
RSP messages
- RSP^K11 - Segment Pattern Response
Related tools
HL7v2 Validator - parse and validate any message in your browser. HL7v2 → FHIR mappings - field-by-field mapping references.