HL7 GT1 Segment: Guarantor: Complete Guide

The GT1 segment identifies the guarantor - the person or organization financially responsible for the patient's bill. It carries the guarantor's name, relationship to the patient, address and contact details, employer, and a range of financial and demographic attributes. GT1 may repeat when more than one party shares financial responsibility.

Purpose

GT1 conveys who pays: the guarantor's identity (GT1-2/GT1-3), their relationship to the patient (GT1-11), employer and employment status, and financial flags used by billing. It is the billing counterpart to the clinical demographic segments.

Used in

GT1 appears in patient-administration and financial messages: ADT (registration/admit events), DFT (detailed financial transactions), and BAR (billing/account). See ADT and DFT.

Field-by-field reference

Source: HAPI HL7v2 v2.5.1 javadocs (GT1) for sequence, name, data type, and repetition. Length is not published in the javadocs (-); Required and Table # are filled from the HL7 v2.5.1 standard where well-established.

Seq	Name	Data Type	Length	Req	Repeat	Table #	Description
GT1-1	Set ID - GT1	SI	-	R	-	-	Sequence number; `1` for the first guarantor.
GT1-2	Guarantor Number	CX	-	O	Y	-	Guarantor account/identifier.
GT1-3	Guarantor Name	XPN	-	R	Y	-	Guarantor's name.
GT1-4	Guarantor Spouse Name	XPN	-	O	Y	-	Spouse name.
GT1-5	Guarantor Address	XAD	-	O	Y	-	Guarantor address.
GT1-6	Guarantor Ph Num - Home	XTN	-	O	Y	-	Home phone.
GT1-7	Guarantor Ph Num - Business	XTN	-	O	Y	-	Business phone.
GT1-8	Guarantor Date/Time Of Birth	TS	-	O	-	-	Date of birth.
GT1-9	Guarantor Administrative Sex	IS	-	O	-	HL70001	Sex.
GT1-10	Guarantor Type	IS	-	O	-	HL70068	Type of guarantor.
GT1-11	Guarantor Relationship	CE	-	O	-	HL70063	Relationship to patient.
GT1-12	Guarantor SSN	ST	-	O	-	-	Social security number.
GT1-13	Guarantor Date - Begin	DT	-	O	-	-	Guarantor effective begin date.
GT1-14	Guarantor Date - End	DT	-	O	-	-	Guarantor end date.
GT1-15	Guarantor Priority	NM	-	O	-	-	Priority among guarantors.
GT1-16	Guarantor Employer Name	XPN	-	O	Y	-	Employer (person) name.
GT1-17	Guarantor Employer Address	XAD	-	O	Y	-	Employer address.
GT1-18	Guarantor Employer Phone Number	XTN	-	O	Y	-	Employer phone.
GT1-19	Guarantor Employee ID Number	CX	-	O	Y	-	Employee id.
GT1-20	Guarantor Employment Status	IS	-	O	-	HL70066	Employment status.
GT1-21	Guarantor Organization Name	XON	-	O	Y	-	Guarantor organization.
GT1-22	Guarantor Billing Hold Flag	ID	-	O	-	HL70136	Billing hold (Y/N).
GT1-23	Guarantor Credit Rating Code	CE	-	O	-	-	Credit rating.
GT1-24	Guarantor Death Date And Time	TS	-	O	-	-	Death date/time.
GT1-25	Guarantor Death Flag	ID	-	O	-	HL70136	Deceased (Y/N).
GT1-26	Guarantor Charge Adjustment Code	CE	-	O	-	HL70218	Charge adjustment.
GT1-27	Guarantor Household Annual Income	CP	-	O	-	-	Household annual income.
GT1-28	Guarantor Household Size	NM	-	O	-	-	Household size.
GT1-29	Guarantor Employer ID Number	CX	-	O	Y	-	Employer id number.
GT1-30	Guarantor Marital Status Code	CE	-	O	-	HL70002	Marital status.
GT1-31	Guarantor Hire Effective Date	DT	-	O	-	-	Hire effective date.
GT1-32	Employment Stop Date	DT	-	O	-	-	Employment stop date.
GT1-33	Living Dependency	IS	-	O	-	HL70223	Living dependency.
GT1-34	Ambulatory Status	IS	-	O	Y	HL70009	Ambulatory status.
GT1-35	Citizenship	CE	-	O	Y	HL70171	Citizenship.
GT1-36	Primary Language	CE	-	O	-	HL70296	Primary language.
GT1-37	Living Arrangement	IS	-	O	-	HL70220	Living arrangement.
GT1-38	Publicity Code	CE	-	O	-	HL70215	Publicity/disclosure code.
GT1-39	Protection Indicator	ID	-	O	-	HL70136	Protection indicator (Y/N).
GT1-40	Student Indicator	IS	-	O	-	HL70231	Student status.
GT1-41	Religion	CE	-	O	-	HL70006	Religion.
GT1-42	Mother's Maiden Name	XPN	-	O	Y	-	Mother's maiden name.
GT1-43	Nationality	CE	-	O	-	HL70212	Nationality.
GT1-44	Ethnic Group	CE	-	O	Y	HL70189	Ethnic group.
GT1-45	Contact Person's Name	XPN	-	O	Y	-	Contact person name.
GT1-46	Contact Person's Telephone Number	XTN	-	O	Y	-	Contact phone.
GT1-47	Contact Reason	CE	-	O	-	-	Reason for contact.
GT1-48	Contact Relationship	IS	-	O	-	HL70063	Contact relationship.
GT1-49	Job Title	ST	-	O	-	-	Job title.
GT1-50	Job Code/Class	JCC	-	O	-	-	Job code/class.
GT1-51	Guarantor Employer's Organization Name	XON	-	O	Y	-	Employer organization name.
GT1-52	Handicap	IS	-	O	-	HL70295	Handicap.
GT1-53	Job Status	IS	-	O	-	HL70311	Job status.
GT1-54	Guarantor Financial Class	FC	-	O	-	HL70064	Financial class.
GT1-55	Guarantor Race	CE	-	O	Y	HL70005	Race.
GT1-56	Guarantor Birth Place	ST	-	O	-	-	Birth place.
GT1-57	VIP Indicator	IS	-	O	-	HL70099	VIP indicator.

Most-used fields

GT1-2 Guarantor Number and GT1-3 Guarantor Name identify the responsible party; GT1-3 is required.
GT1-11 Guarantor Relationship ties the guarantor to the patient (self, spouse, parent).
GT1-15 Guarantor Priority orders multiple guarantors; GT1-21 names an organizational guarantor.

Version differences (2.3 to 2.8.2)

2.3/2.4: core guarantor fields present; coded fields used CE.
2.5: demographic fields (GT1-33 to GT1-57) added, mirroring PID demographics.
Later versions retain GT1 largely unchanged; receivers ignore trailing fields they do not support.

Common mistakes

Treating GT1 as non-repeating - multiple guarantors are valid and ordered by GT1-15.
Reading GT1-3 as a simple string and losing XPN name components.
Confusing the guarantor (GT1) with the insured/subscriber (IN1).

Examples

Minimal valid GT1:

GT1|1||DOE^JOHN^Q

Fully-populated GT1:

GT1|1|G55||DOE^JOHN^Q||100 MAIN ST^^METROPOLIS^IL^60601||(555)555-0100||19800101|M|SE|SEL^Self^HL70063|999-99-9999

Annotated breakdown of the fully-populated example (selected fields):

GT1                       ← segment ID
1                         ← GT1-1  Set ID
G55                       ← GT1-2  Guarantor Number
DOE^JOHN^Q                ← GT1-3  Guarantor Name
100 MAIN ST^^METROPOLIS…  ← GT1-5  Guarantor Address
19800101                  ← GT1-8  Date of Birth
M                         ← GT1-9  Administrative Sex
SE                        ← GT1-10 Guarantor Type
SEL^Self^HL70063          ← GT1-11 Guarantor Relationship
999-99-9999               ← GT1-12 Guarantor SSN

In-context inside an ADT^A01 (admit):

MSH|^~&|REG|MERCYGEN|EHR|MERCYGEN|20260610090000||ADT^A01^ADT_A01|MSG901|P|2.5.1
PID|1||MR12345^^^MERCYGEN^MR||DOE^JOHN^Q||19800101|M
PV1|1|I|3WEST^301^A
GT1|1|G55|DOE^JOHN^Q||100 MAIN ST^^METROPOLIS^IL^60601|||19800101|M||SEL^Self^HL70063

In-context inside a DFT^P03 (financial transaction):

MSH|^~&|ADT|MERCYGEN|FIN|MERCYGEN|20260610120000||DFT^P03^DFT_P03|MSG902|P|2.5.1
PID|1||MR12345^^^MERCYGEN^MR||DOE^JOHN^Q||19800101|M
GT1|1|G55|DOE^JOHN^Q
FT1|1||||20260610|20260610|CG|99213^Office Visit^CPT

FHIR mapping

No segment-level ConceptMap is published in the v2-to-FHIR IG for GT1. Conceptually the guarantor maps to Account.guarantor referencing a RelatedPerson (or Patient/Organization), with financial-class details informing Coverage. Implementations define this mapping locally.

Engine considerations

Required in practice: GT1-1 and GT1-3; billing interfaces also expect GT1-11 (relationship).
Preserve repeating GT1 segments and the GT1-15 priority ordering.
Distinguish GT1 (who pays) from IN1 (insurance coverage) when routing to billing.

How Vorro parses and produces GT1

Vorro preserves repeating GT1 segments and their priority order, decomposes XPN/XAD/XTN components, and maps the guarantor to the account's responsible party on the FHIR side, keeping it distinct from insurance coverage derived from IN1.

IN1 - insurance coverage, the companion financial segment.
PID - the patient the guarantor is responsible for.
ADT messages - where GT1 accompanies registration.

Sources

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HL7 GT1 Segment: Guarantor