SIU^S13 — Notification of Appointment Rescheduling

The message that announces the reschedule of an existing appointment to a new date/time. Broadcast to the EHR, the practitioner calendar, the patient portal and the SMS reminder module.

Purpose

S13 fires when a patient (or their assistant) asks to move an appointment from D to D+15 (for example). Unlike S12 (new booking) or S15 (cancellation), S13 keeps the same appointment identifier — only date/time change. Consumer systems must match on SCH-1 to update their calendar, and emit a refreshed SMS reminder.

Segment structure

SIU_S13
  MSH                    Message Header
  SCH                    Scheduling Activity Information
  [ { NTE } ]            Notes
  [ { PID                Patient Identification (1..*)
    [ PD1 ]              Patient Additional Demographics
    [ { PV1 } ]
    [ { PV2 } ]
    [ { OBX } ]
    [ { DG1 } ]
  } ]
  { RGS                  Resource Group Segment (1..*)
    { AIS | AIG | AIL | AIP }
    [ { NTE } ]
  }

Real-world example

Reschedule of an appointment from 20/05 to 01/06 with Dr Jones:

MSH|^~\&|SCHED|HOSP01|EHR|HOSP01|20260516130000||SIU^S13^SIU_S13|MSG-SIU-S13-001|P|2.5.1|||AL|NE
SCH|APP2026-042||APPT2026-042||1^Routine||CONS^Consultation||30|min|^^^20260601100000^20260601103000|||||DRJONES^Jones^Sarah^^^DR.|+33142000000^^WORK||||DRJONES^Jones^Sarah^^^DR.|||||Booked
PID|1||MRN567890^^^HOSP^MR||DOE^JOHN^A^^MR.||19720515|M
PV1|1|O|CARDIO^^^HOSP01|||||DRJONES^Jones^Sarah^^^DR.
RGS|1|A
AIS|1|A|99213^Office visit, level 3^CPT||20260601100000|||||1800
AIL|1|A|CARDIO-101^^Cardiology Room 101^Cardiology Floor^^HOSP01
AIP|1|A|DRJONES^Jones^Sarah^^^DR.|RP^Responsible Provider^HL70443|20260601100000

• SCH-1 = APP2026-042 (preserved identifier of the initial appointment).
• SCH-11 = new date 20260601100000.
• AIS-5 / AIP-5 = new date replicated.

Acknowledgment (ACK)

MSH|^~\&|EHR|HOSP01|SCHED|HOSP01|20260516130001||ACK^S13^ACK|ACK-SIU-S13-001|P|2.5.1
MSA|AA|MSG-SIU-S13-001

Common errors

• SCH-1 modified: appointment ID must stay stable. Changing it creates a new appointment instead of rescheduling the existing one.
• No patient notification: upon receipt, the portal / SMS system must notify the patient. Without contact for notification, S13 is ineffective.
• Resource (AIG / AIL) unchanged when it should be: if the new slot is not the same room, update AIL.
• S13 without prior S12: S13 reschedules an existing appointment; if the original appointment was never created (no S12), emit an S12 instead.
• Filling status not updated: SCH-25 Filling Status must reflect the new state (Booked vs Rescheduled per the convention).

Related messages

See also: SIU^S12 — new appointment and FHIR Appointment.