HL7 ADT_A11 Cancel Admit/Visit Notification

The earlier admit or visit notification should be backed out.
HL7 message structure ADT_A09 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

SegmentNameRequiredRepeatable
MSH
 Message Header Yes No
SFT
 Software Segment No Yes
EVN
 Event Type Yes No
PID
 Patient Identification Yes No
PD1
 Patient Additional Demographic No No
PV1
 Patient Visit Yes No
PV2
 Patient Visit - Additional Information No No
DB1
 Disability No Yes
OBX
 Observation/Result No Yes
DG1
 Diagnosis No Yes

ADT_A11 cancels an earlier admit or visit notification, usually an A01 or A04. It is sent when the original event was entered in error or the decision changed before the visit should stand as active in receiving systems.

On the wire, A11 commonly uses ADT^A11^ADT_A09. That can look odd at first, but it is normal HL7: A11 is the business event, while ADT_A09 is the shared tracking-style structure. The structure panel below shows that backing structure.

A small A11 example

MSH|^~\&|REG|CITYHOSP|EHR|CITYHOSP|20260715084500||ADT^A11^ADT_A09|ADT110001|P|2.5.1 EVN|A11|20260715084400|||REGCLERK^Riley^Morgan PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L||19800314|F PV1|1|O|ED^TRIAGE^1^CITYHOSP||||12345^Careful^Clara|||||||||||VST440001^^^CITYHOSP^VN

What systems do with it

The sender is usually the same ADT/registration source that created the original visit. Receivers use PID and PV1 to find the patient and encounter to cancel. The expected action is usually to restore the patient or visit state to what it was before the canceled A01 or A04.

That restoration might mean closing a pending visit, undoing an active encounter, removing a census row, suppressing downstream notifications, or canceling pending ancillary context. It should not normally mean deleting all patient history. Most receivers need an audit trail that a visit was created and then canceled.

How to read the structure

The ADT_A09 backing structure is compact: MSH, EVN, PID, optional PD1, required PV1, optional PV2, disability, observations, and diagnosis. A11 does not need the full insurance/procedure/billing-heavy shape of ADT_A01 because it is mainly identifying the visit to unwind.

The visit number in PV1 is the anchor. If the original A01 or A04 created a visit number, send the same one in A11. If the receiver cannot identify the visit, the safest behavior is an application error rather than canceling the wrong encounter.

Implementation traps

A11 is not a discharge. A discharge says the visit happened and has ended. A cancel admit or cancel visit says the original admit/visit event should not stand. Mixing those two creates messy downstream history, especially for bed tracking and billing.

Also be careful with resend behavior. If an A11 is replayed after a timeout, the receiver should be able to answer consistently without trying to cancel a different active visit for the same patient.

Reference notes

Caristix's IHE France PAM reference and IHE Patient Encounter Management mappings published by Oracle describe A11 as canceling an admit or visit notification and show ADT^A11^ADT_A09 as the message type and structure pairing. The IHE reference says the receiver should reset patient status to the value that existed before the admit or visit notification.