X12 segment reference
GS — Functional Group Header
Learn the X12 GS segment: functional ID codes, application sender/receiver, group control numbers, and version identifiers.
GS segment facts
- GS01 functional ID code determines which transaction family the enclosed ST segments belong to.
- GS06 group control numbers are echoed in 997 AK1 segments when partners acknowledge or reject a functional group.
- GS08 version must match the implementation guide your partner certified — retail 005010 differs from HIPAA 005010X222A1.
What the GS segment does
GS groups related transaction sets (for example all purchase orders in one batch). GS01 functional ID tells parsers whether the group carries PO, invoice, or acknowledgement traffic.
Key elements
| Element | Name | Description |
|---|---|---|
| GS01 | Functional ID code | PO for 850 groups, SH for 856, IN for 810, FA for 997. |
| GS02 | Application sender code | Often mirrors your ISA sender but at application level. |
| GS06 | Group control number | Referenced by GE and by 997 AK1 when partners acknowledge the group. |
| GS08 | Version / release | 005010 for most retail; 005010X222A1 for HIPAA 837. |
Example GS segment
GS*PO*SENDER*RECEIVER*20250609*1200*1*X*005010~
Parse and validate samples with the free EDI validator or send JSON via the JSON→X12 mapping guide.
Related reference
FAQ
Frequently asked questions
PO = purchase order group, SH = ship notice/ASN group, IN = invoice group, FA = functional acknowledgement group.