HL7 SIU^S12 (New Appointment Booking)
SIU^S12 notifies systems of a new appointment booking. The SCH segment carries the appointment id, type, duration and timing; resource/location segments (RGS, AIL, AIS, AIP) describe what and who the appointment involves.
When is SIU^S12 sent?
Sent by a scheduling system when a new appointment is booked. Other SIU events (S13 reschedule, S15 cancel, S26 no-show) cover later changes.
Key segments
The segments below are the ones most relevant to SIU^S12. Real messages may carry additional optional segments depending on the sending system’s configuration.
| Segment | Usage | Role |
|---|---|---|
| MSH | Required | Message header: sending/receiving application & facility, message type, control id, version. |
| SCH | Required | Scheduling activity: appointment id, appointment type/reason, duration, and the start/end timing quantity. |
| PID | Required | Patient identification: identifiers (MRN), name, date of birth, sex, address, phone. |
| PV1 | Optional | Patient visit: patient class, assigned location, attending provider, admit/discharge details. |
| RGS | Optional | Resource group: groups the resource/location segments that follow. |
| AIL | Optional | Appointment information, location resource: the location/department for the appointment. |
Full message structure (v2.8.2)
Every segment and group the standard defines for SIU^S12, in order, straight from the machine-readable specification. Indented rows sit inside the repeating group above them. R is required, O optional, C conditional; ∞ means the group or segment may repeat without a defined limit.
| Segment / group | Usage | Repeats |
|---|---|---|
| MSH | R | 1 |
| SCH | R | 1 |
| TQ1 | O | ∞ |
| NTE | O | ∞ |
| PATIENT (group) | O | ∞ |
| PID | R | 1 |
| PD1 | O | 1 |
| PV1 | O | 1 |
| PV2 | O | 1 |
| OBX | O | ∞ |
| DG1 | O | ∞ |
| RESOURCES (group) | R | ∞ |
| RGS | R | 1 |
| SERVICE (group) | O | ∞ |
| AIS | R | 1 |
| NTE | O | ∞ |
| GENERAL_RESOURCE (group) | O | ∞ |
| AIG | R | 1 |
| NTE | O | ∞ |
| LOCATION_RESOURCE (group) | O | ∞ |
| AIL | R | 1 |
| NTE | O | ∞ |
| PERSONNEL_RESOURCE (group) | O | ∞ |
| AIP | R | 1 |
| NTE | O | ∞ |
Which HL7v2 versions changed SIU^S12?
SIU^S12 has been defined since v2.3. Consecutive versions sharing an identical structure are grouped, so a single row spanning several versions means nothing changed across them.
| Versions | What changed |
|---|---|
| v2.3 | First defined, with 23 segments and groups. |
| v2.3.1 - v2.4 | Added PD1. |
| v2.5 - v2.8.2 | Added TQ1. |
Example SIU^S12 message
A realistic, well-formed example. Segments are separated by carriage returns; fields by the pipe (|) delimiter.
MSH|^~\&|SCHED|HOSP|REC|REC|20240116090000||SIU^S12|MSGCTRL5555|P|2.5.1
SCH|APPT123^SCHED||||||CONSULT^Consultation|30|min|^^30^202402011400^202402011430|||||DOE^JOHN^A
PID|1||MRN12345^^^EPIC^MR||DOE^JOHN^A||19800101|M
PV1|1|O|CLINIC^A^1
RGS|1|A
AIL|1||CLINIC^Cardiology Clinic^DEPTMapping SIU^S12 to FHIR
See the full field-by-field mapping of SIU^S12 to a FHIR Appointment - including the transforms and gotchas - on the SIU^S12 → FHIR Appointment reference page. You can fork that template and run it in the Mapping Builder.
Frequently asked questions
What is an HL7 SIU^S12 message?
SIU^S12 is a scheduling information unsolicited message for a new appointment booking. The SCH segment describes the appointment and the AIS/AIL/AIP resource segments describe the service, location, and personnel involved.
What does the SCH segment contain?
SCH carries the appointment identifier, appointment reason/type, duration and units, and the appointment timing quantity (which includes the start and end date/time in its components).
How do I map SIU^S12 to a FHIR Appointment?
Set Appointment.status to booked, map SCH appointment id to identifier, SCH type to serviceType, the timing components to start/end, and the AIL location to a participant. The Interoperall template shows the full rule set.
How do I validate an SIU^S12 message?
Paste it into the HL7v2 validator to parse the SCH/RGS/AIL structure and verify it is well-formed, entirely in your browser.