HL7 ADT^A11 (Cancel Admit)
ADT^A11 cancels a prior admit (A01). It tells receivers to reverse the admission, for example when an A01 was sent in error.
When is ADT^A11 sent?
Sent to undo an admission notification before the patient is actually admitted, or to correct an erroneous A01.
Key segments
The segments below are the ones most relevant to ADT^A11. 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. |
| EVN | Required | Event type: the trigger event code and the date/time the event occurred. |
| 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. |
Full message structure (v2.8.2)
Every segment and group the standard defines for ADT^A11, 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 |
| SFT | O | ∞ |
| UAC | O | 1 |
| EVN | R | 1 |
| PID | R | 1 |
| PD1 | O | 1 |
| PV1 | R | 1 |
| PV2 | O | 1 |
| DB1 | O | ∞ |
| OBX | O | ∞ |
Which HL7v2 versions changed ADT^A11?
ADT^A11 has been defined since v2.1. Consecutive versions sharing an identical structure are grouped, so a single row spanning several versions means nothing changed across them.
| Versions | What changed |
|---|---|
| v2.1 | First defined, with 5 segments and groups. |
| v2.2 | Added OBX, PV2. |
| v2.3 - v2.5.1 | Added DB1, PD1. |
| v2.6 | Added SFT, UAC. |
| v2.7 - v2.8.2 | Removed DG1. |
Example ADT^A11 message
A realistic, well-formed example. Segments are separated by carriage returns; fields by the pipe (|) delimiter.
MSH|^~\&|EPIC|HOSP|REC|REC|20240115094500||ADT^A11|MSGCTRLA11|P|2.5.1
EVN|A11|20240115094500
PID|1||MRN12345^^^EPIC^MR||DOE^JOHN^A||19800101|M|||123 MAIN ST^^CITYTOWN^WA^98101||555-555-0100
PV1|1|I|ICU^101^AFrequently asked questions
What is an HL7 ADT^A11 message?
ADT^A11 is an ADT (Admit, Discharge, Transfer) message with trigger event for cancel admit. It carries patient demographics (PID) and usually visit details (PV1) so downstream systems stay in sync with the patient's state.
Which segments does ADT^A11 contain?
At minimum MSH (header), EVN (event), and PID (patient identification). Most ADT^A11 messages also include PV1 (patient visit). Additional segments such as NK1, AL1, DG1 or IN1 may follow depending on the sending system's configuration.
How do I convert ADT^A11 to FHIR?
Map the PID demographics to a FHIR Patient (and PV1 to an Encounter). Identifiers need a real system URI, dates need ISO-8601 reformatting, and coded values like sex need a value-set lookup. You can do this with the Interoperall mapping tools.
How do I validate a ADT^A11 message?
Paste the raw message into the HL7v2 validator to parse each segment, check the structure, and get a compliance score. It runs entirely in your browser, so PHI never leaves your device.