HL7 BAR_P01 Add Patient Account

Open a billing account without pretending the patient just arrived.
HL7 message structure BAR_P01 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
BAR_P01.VISIT
 Visit group Yes Yes
PV1
 Patient Visit No 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
BAR_P01.PROCEDURE
 Procedure group No Yes
PR1
 Procedures Yes No
ROL
 Role No Yes
GT1
 Guarantor No Yes
NK1
 Next of Kin / Associated Parties No Yes
BAR_P01.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
UB1
 UB82 No No
UB2
 UB92 Data No No

BAR_P01 is a billing account record message used to establish a patient account in a patient accounting or financial system. It is usually sent from registration, ADT, or another administrative source to billing when the financial account needs to exist independently of a simple admit or visit notification.

That distinction is the reason BAR exists. An ADT_A01 can tell systems a patient arrived and may also create account context, but BAR_P01 says "create this account" without necessarily changing patient location, census, or clinical availability.

A small BAR_P01 example

MSH|^~\&|REG|CITYHOSP|BILLING|CITYHOSP|20260715110000||BAR^P01^BAR_P01|BAR010001|P|2.5.1 EVN|P01|20260715105500 PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L||19800314|F||||||||||ACC000789^^^CITYHOSP^AN PV1|1|O|CLINIC^12^1^CITYHOSP||||12345^Careful^Clara|||||||||||VN000345^^^CITYHOSP^VN GT1|1|G12345|Smith^Jane||12 High Street^^Auckland^^1010^NZ^H IN1|1|PLAN-A|INS001|City Health Plan

What systems do with it

The sender is commonly an ADT/registration system. The receiver is usually patient accounting, accounts receivable, claims, or revenue-cycle software. The receiver creates the account shell, links it to the patient and visit context, and records guarantor, insurance, diagnosis, procedure, accident, or UB billing data when the sender supplies it.

Use BAR_P01 when the account start is the business event. If the patient demographics changed, send the appropriate ADT update. If the account already exists, use an account update workflow rather than opening another account with a new P01.

How to read the structure

The core is MSH, EVN, and PID. The repeating visit group can carry PV1, PV2, DG1, PR1, GT1, NK1, IN1, ACC, UB1, and UB2. That breadth lets a financial receiver create a usable account without waiting for several separate messages.

Implementation traps

Do not use P01 as a generic account refresh. From HL7 v2.3 onward, P01 is for adding an account that did not exist before. Duplicate account creation is one of those problems that looks harmless in a test feed and turns ugly in claims, statements, and reconciliation.

Also make sure the account identifier, visit number, and patient identifier are not treated as the same thing. PID-18 account number and PV1-19 visit number carry different meanings in most billing systems.

Reference notes

The HL7 v2+ BAR_P01 page describes P01 as establishing a billing/accounts receivable record and notes that P05 should update existing accounts while P06 should close accounts. The iNTERFACEWARE BAR overview gives the same practical framing: BAR messages add or change patient billing account information.