ISA (Interchange Control Header Segment)

The ISA is a fixed record length segment and all positions within each of the data elements are required. The first element separator defines the element separator used through the entire interchange. The segment terminator used after the ISA defines the segment terminator to be used throughout the entire interchange.

The Input Data column below contains text in [bracketed italics], which indicates special input data dependent on sender, time, date, etc.

Elements  Size  Name  Input Data  Remarks     

ISA01  Authorization Information Qualifier  00  No Authorization Information Present.    

ISA02  10  Authorization Information  [Submitter-specific ID number, or ten-space placeholder]  If no Authorization Information number is present, simply enter10 spaces in this field.    

ISA03  Security Information Qualifier  00  No Security Information Present.    

ISA04  10  Security Information/Password  [Submitter-specific ID number, or ten-space placeholder]  If no Authorization
Information number is present, simply enter10 spaces in this field.    

ISA05  Interchange ID Qualifier/Trading Partner Qualifier  ZZ  Mutually Agreed.    

ISA06  15  Interchange Sender ID/ Trading Partner ID  [Tufts Health Plan Submitter ID]  Sender ID (Provided by Tufts
Health Plan).    

ISA07  Interchange ID Qualifier/Tufts Health Plan Qualifier  01  DUNS (Dun & Bradstreet).    

ISA08  15  Interchange Receiver ID/Tufts Health Plan ID  170558746  Tufts Health Plan DUNS.    

ISA09  Interchange Date  [Enter the date using the format YYMMDD; for example, January 1, 2012 would be entered as
120101]  Date of the interchange. 

ISA10  Interchange Time  [Enter the time using the format HHMM; for example, 1:30 PM would be entered as 1330]  Time of the interchange.   

ISA11  Repetition Separator  The repetition separator is a delimiter and not a data element; this field provides the delimiter used to separate repeated occurrences of a simple data element or a composite data structure; this value must be different than the data element separator, component element separator, and the segment terminator.    

ISA12  Interchange Control Version Number  Version Number.    

ISA13  Interchange Control Number/Last Control Number  [Sender-specific control number]  Assigned and maintained by the interchange sender, must be identical to the associated Interchange Trailer, IEA02.

Must increment by one number at the end of the value with each file submitted within the same business day (12:00 am to 11:59 pm).    

ISA14  Acknowledgement Request  [Enter either 0 or 1]  The 999 will be sent regardless of Input Data.    

ISA15  Interchange Usage Indicator/ Acknowledgment Test Indicator  [Enter either T or P]  T - Test Data,   P - Production Data. 

ISA16  Component Element Separator (Sub-Element)  [Enter any separator character, for example : or >]  Used to separate component data elements within a composite data structure; must be unique.

ASCII Value - Component element separator.


[[1] EDI X12 Structure: Interchange Control Header | EDI Blog (

[[2] ICS Interchange Control Structures (