HL7 ADT_A16 Pending Discharge

The patient is expected to leave, but the discharge has not happened yet.
HL7 message structure ADT_A16 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

SegmentNameRequiredRepeatable
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
ROL
 Role No Yes
NK1
 Next of Kin / Associated Parties No Yes
PV1
 Patient Visit Yes No
PV2
 Patient Visit - Additional Information No No
ROL
 Role No Yes
DB1
 Disability No Yes
OBX
 Observation/Result No Yes
AL1
 Patient Allergy Information No Yes
DG1
 Diagnosis No Yes
DRG
 Diagnosis Related Group No No
ADT_A16.PROCEDURE
 Procedure group No Yes
PR1
 Procedures Yes No
ROL
 Role No Yes
GT1
 Guarantor No Yes
ADT_A16.INSURANCE
 Insurance group No Yes
IN1
 Insurance Yes No
IN2
 Insurance Additional Information No No
IN3
 Insurance Additional Information, Certification No Yes
ROL
 Role No Yes
ACC
 Accident No No

ADT_A16 is a heads-up message. It tells systems that a discharge is planned so pharmacy, transport, care coordination, home health, billing, and downstream clinical systems can prepare before the patient actually leaves the facility.

The actual discharge/end-visit event is A03. A16 should prepare the workflow; it should not close the visit unless your local profile has made an explicit and unusual decision to do that.

A small A16 example

MSH|^~\&|ADT|CITYHOSP|CARECOORD|CITYHOSP|20260715130000||ADT^A16^ADT_A16|ADT160001|P|2.5.1 EVN|A16|20260715125900 PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L||19800314|F PV1|1|I|WARD1^101^1^CITYHOSP^^BED||||12345^Ng^Grace|||||||||||VN000345^^^CITYHOSP^VN PV2||||||||||||||||||||||||20260716100000

What systems do with it

The sender is usually the PAS/EHR, discharge planning module, or bed management system. Receivers may prepare discharge medications, schedule post-discharge appointments, stage transport, warn dietetics, or mark a bed as likely to become available.

Systems that cannot model pending discharge safely should usually log the message and wait for A03 rather than pretending the patient has already left.

How to read the structure

ADT_A16 has a broad admission-style structure. The reliable core is MSH, EVN, PID, and PV1. Optional segments such as NK1, AL1, DG1, PR1, GT1, and IN1 appear when the pending discharge feed is also feeding care coordination or billing context.

Implementation traps

Do not release the bed, stop medication workflows, or close orders just because an A16 arrived. Treat it as expected state and let A03 do the closing work. Also watch for profiles that cancel pending discharge separately; otherwise a patient can remain flagged for discharge after the plan changes.

Reference notes

The HL7 v2+ ADT_A16 page describes A16 as advance notification of a discharge plan, before the patient has left the healthcare facility.