ADT^A30 — Merge Person Information
Merge two MPI identities. PID carries the surviving identity, MRG carries the identifiers being absorbed. A30 operates at Person level (no visit), A40 at Patient ID level.
Purpose
A30 merges two MPI identities: duplicates identified after the fact by a probabilistic matching algorithm or by manual review. The surviving identity is carried by PID, the absorbed identity by MRG.
Segment structure
Structure ADT_A39 shared with A30, A34, A35, A36, A39, A40, A41, A42,
A43, A44, A45, A46, A47, A48, A49, A50, A51. MSH, EVN, PID, MRG.
Real-world example
Merge of MR100201 (duplicate) into MR100200 (survivor) for Marie Dupont:
MSH|^~\&|MPI|HOSP01|EHR|CLINIC02|20260518100000||ADT^A30^ADT_A39|MSG00030001|P|2.5.1|||AL|NE
EVN|A30|20260518100000|||MPI001^Manager^Merger^^^MS.|MERGE DUPLICATE PERSONS
PID|1||MR100200^^^HOSP^MR||DUPONT^MARIE^^^MS.||19800615|F|||10 RUE DE LA PAIX^^PARIS^^75002^FRA||+33145001234
MRG|MR100201^^^HOSP^MRAcknowledgment (ACK)
MSH|^~\&|EHR|CLINIC02|MPI|HOSP01|20260518100001||ACK^A30^ACK|ACK00030001|P|2.5.1
MSA|AA|MSG00030001Common errors
- Inverted MRG: PID must carry the survivor, MRG carries the absorbed. Inverted, data is lost.
- A30 on identity with active visits: some receivers require A40 (Merge Patient ID) which propagates to visits. A30 is Person only.
- No AuditEvent: every merge must be traced for regulatory traceability.
Related ADT events
| Code | Trigger event | Description |
|---|---|---|
| A30 | Merge Person Information | This page. |
| A39 | Merge Person — Patient ID | Variant impacting Patients. |
| A40 | Merge Patient — Patient ID | Merge at Patient ID level (with visits). |
| A18 | Merge Patient Information | Legacy variant (v2.3 and earlier). |