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HL7 v2Segment⏱ 9 min read

HL7 GT1 Segment: Guarantor

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.

SeqNameData TypeLengthReqRepeatTable #Description
GT1-1Set ID - GT1SI—R——Sequence number; 1 for the first guarantor.
GT1-2Guarantor NumberCX—OY—Guarantor account/identifier.
GT1-3Guarantor NameXPN—RY—Guarantor's name.
GT1-4Guarantor Spouse NameXPN—OY—Spouse name.
GT1-5Guarantor AddressXAD—OY—Guarantor address.
GT1-6Guarantor Ph Num - HomeXTN—OY—Home phone.
GT1-7Guarantor Ph Num - BusinessXTN—OY—Business phone.
GT1-8Guarantor Date/Time Of BirthTS—O——Date of birth.
GT1-9Guarantor Administrative SexIS—O—HL70001Sex.
GT1-10Guarantor TypeIS—O—HL70068Type of guarantor.
GT1-11Guarantor RelationshipCE—O—HL70063Relationship to patient.
GT1-12Guarantor SSNST—O——Social security number.
GT1-13Guarantor Date - BeginDT—O——Guarantor effective begin date.
GT1-14Guarantor Date - EndDT—O——Guarantor end date.
GT1-15Guarantor PriorityNM—O——Priority among guarantors.
GT1-16Guarantor Employer NameXPN—OY—Employer (person) name.
GT1-17Guarantor Employer AddressXAD—OY—Employer address.
GT1-18Guarantor Employer Phone NumberXTN—OY—Employer phone.
GT1-19Guarantor Employee ID NumberCX—OY—Employee id.
GT1-20Guarantor Employment StatusIS—O—HL70066Employment status.
GT1-21Guarantor Organization NameXON—OY—Guarantor organization.
GT1-22Guarantor Billing Hold FlagID—O—HL70136Billing hold (Y/N).
GT1-23Guarantor Credit Rating CodeCE—O——Credit rating.
GT1-24Guarantor Death Date And TimeTS—O——Death date/time.
GT1-25Guarantor Death FlagID—O—HL70136Deceased (Y/N).
GT1-26Guarantor Charge Adjustment CodeCE—O—HL70218Charge adjustment.
GT1-27Guarantor Household Annual IncomeCP—O——Household annual income.
GT1-28Guarantor Household SizeNM—O——Household size.
GT1-29Guarantor Employer ID NumberCX—OY—Employer id number.
GT1-30Guarantor Marital Status CodeCE—O—HL70002Marital status.
GT1-31Guarantor Hire Effective DateDT—O——Hire effective date.
GT1-32Employment Stop DateDT—O——Employment stop date.
GT1-33Living DependencyIS—O—HL70223Living dependency.
GT1-34Ambulatory StatusIS—OYHL70009Ambulatory status.
GT1-35CitizenshipCE—OYHL70171Citizenship.
GT1-36Primary LanguageCE—O—HL70296Primary language.
GT1-37Living ArrangementIS—O—HL70220Living arrangement.
GT1-38Publicity CodeCE—O—HL70215Publicity/disclosure code.
GT1-39Protection IndicatorID—O—HL70136Protection indicator (Y/N).
GT1-40Student IndicatorIS—O—HL70231Student status.
GT1-41ReligionCE—O—HL70006Religion.
GT1-42Mother's Maiden NameXPN—OY—Mother's maiden name.
GT1-43NationalityCE—O—HL70212Nationality.
GT1-44Ethnic GroupCE—OYHL70189Ethnic group.
GT1-45Contact Person's NameXPN—OY—Contact person name.
GT1-46Contact Person's Telephone NumberXTN—OY—Contact phone.
GT1-47Contact ReasonCE—O——Reason for contact.
GT1-48Contact RelationshipIS—O—HL70063Contact relationship.
GT1-49Job TitleST—O——Job title.
GT1-50Job Code/ClassJCC—O——Job code/class.
GT1-51Guarantor Employer's Organization NameXON—OY—Employer organization name.
GT1-52HandicapIS—O—HL70295Handicap.
GT1-53Job StatusIS—O—HL70311Job status.
GT1-54Guarantor Financial ClassFC—O—HL70064Financial class.
GT1-55Guarantor RaceCE—OYHL70005Race.
GT1-56Guarantor Birth PlaceST—O——Birth place.
GT1-57VIP IndicatorIS—O—HL70099VIP 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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