ADT^A03 is always paired with a prior ADT^A01 (or A04 for outpatients). When a patient is discharged, the ADT system fires A03 to close the visit in every downstream system — lab stops accepting orders, billing finalizes charges, and bed management marks the bed available.
What is ADT^A03?
The A03 event marks the end of a patient visit. The message carries the discharge date/time, disposition code (where the patient went — home, SNF, expired), and the final DRG assignment for billing.
When is ADT^A03 triggered?
- Inpatient discharge — patient formally discharged by physician order
- Death in hospital — discharge disposition 20 (Expired)
- Transfer to another facility — discharge from current facility
- Outpatient visit end — clinic appointment or ED visit closed
Message Flow
Segments in this Message
Cardinality: [X] optional · {X} repeating · [{X}] optional & repeating
| Segment | Name | Required | Description |
|---|---|---|---|
MSH | Message Header | Required | MSH-9 = ADT^A03^ADT_A03. |
EVN | Event Type | Required | EVN-1 = A03. EVN-2 = recorded discharge date/time. |
PID | Patient Identification | Required | PID-3 MRN is the key used to match and close the encounter downstream. |
PV1 | Patient Visit | Required | PV1-36 = discharge disposition (01=Home, 20=Expired). PV1-44 = admit date, PV1-45 = discharge date/time. |
DG1 | Diagnosis | Optional | Final discharge diagnoses (type F = Final). Multiple DG1 segments for principal + secondary. |
DRG | Diagnosis-Related Group | Optional | DRG-1 = MS-DRG code. Required for inpatient billing. DRG-7 = outlier type. |
HL7 Message Example
MSH|^~&|EPIC|MERCY|BILLING|MERCY|20240117163500||ADT^A03^ADT_A03|MSG20240117009|P|2.5.1
EVN|A03|20240117163500
PID|1||MRN-78234^^^MERCY^MR||SMITH^JOHN^ROBERT^^MR||19800315|M
PV1|1|I|MICU^2B^01^MERCY||||1234^JONES^DAVID^R^^DR|||01^Discharged to home^HL70112|||||||||||IP-78234^^^MERCY^VN|||||||||||||||||||20240115083000|20240117160000
DG1|1||I10^Essential (primary) hypertension^I10||20240117|F
DG1|2||J18.9^Pneumonia, unspecified^I10||20240117|F
DRG|470^Major joint replacement^MS-DRG|20240117||2FHIR Mapping
| Segment | FHIR | Notes |
|---|---|---|
| PV1-36 (disposition) | Encounter.hospitalization.dischargeDisposition | HL70112 codes |
| PV1-45 (discharge date) | Encounter.period.end | status → finished |
| DG1 final diagnoses | Condition resources | Multiple Conditions linked to Encounter |
Common Errors & Pitfalls
- PV1-36 (discharge disposition) missing — required for billing. Use HL70112 code table.
- PV1-45 (discharge date) missing — needed for LOS calculation and billing.
- DRG not populated — often sent later via A08 update. Coordinate with revenue cycle.
- No matching A01 found — use visit number (PV1-19) for matching, not just MRN.
Vorro matches A03 to the originating A01 using PID-3 (MRN) + PV1-19 (visit number). If no open encounter is found, the message is held in a review queue. Configure automatic DRG enrichment by linking Vorro to your grouper service.
