All termsProtocols
HL7 ADT
An HL7 v2 message conveying Admission, Discharge, and Transfer events — the backbone of patient identity and location updates.
When to use it
Whenever downstream systems need to stay in sync with registration, movement, and merges.
In plain terms
The hospital-wide announcement that a patient arrived, moved, or left.
Common gotchas
- ADT is the usual patient-identity feed — merges (A40) and updates (A08) must be handled or IDs drift.
- Event types (A01 admit, A03 discharge, A08 update…) each need mapping.
- High volume; a backlog here ripples everywhere.