HL7 ADT_A45 (Move Visit Information - Visit Number) | Integration Soup HL7 Reference Guide

HL7 ADT_A45 Move Visit Information - Visit Number

A visit was filed under the wrong account or patient context and needs to move.

HL7 message structure ADT_A45 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

Segment	Name	Required	Repeatable
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
ADT_A45.MERGE_INFO	Merge Info group	Yes	Yes
MRG	Merge Patient Information	Yes	No
PV1	Patient Visit	Yes	No

ADT_A45 is a move event at the visit identifier level. It is used when records identified by a prior visit number or alternate visit ID need to move from an incorrect source account to the correct target account.

That makes A45 more specific than a patient merge. The patient identity may be known, but the visit-level filing is wrong.

A small A45 example

MSH|^~\&|MPI|CITYHOSP|EHR|CITYHOSP|20260715155500||ADT^A45^ADT_A45|ADT450001|P|2.5.1 EVN|A45|20260715155400 PID|1||123456^^^CITYHOSP^MR|||||||||||||||ACC0002^^^CITYHOSP^AN MRG|123456^^^CITYHOSP^MR||ACC0001^^^CITYHOSP^AN||VNOLD001^^^CITYHOSP^VN PV1|1|I|WARD1^101^1^CITYHOSP^^BED||||12345^Ng^Grace|||||||||||VN000345^^^CITYHOSP^VN

What systems do with it

The sender is usually registration correction, MPI, or a patient-accounting component. Receivers move visit-scoped data from the prior visit/account context in MRG to the target account and visit context carried in PID and PV1.

How to read the structure

The local structure has MSH, EVN, PID, optional PD1, and a repeating merge-info group with required MRG and required PV1. MRG-5 is the prior visit number, while PV1-19 carries the target visit number when a new visit number is part of the move.

Implementation traps

Do not move the whole patient when only a visit is being corrected. Also make sure all superior identifiers are populated consistently: patient identifier, account number, and visit number each have a different job here.

Reference notes

The HL7 v2+ ADT_A45 page describes moving records identified by MRG-5 prior visit number or MRG-6 prior alternate visit ID to the correct target account identifier.