ANSI X12 837P - 4010 ISA & IEA Interchange Control Header and Trailer
September 21, 2025
The ISA (Interchange Control Header) and IEA (Interchange Control Trailer) segments are the opening and closing “envelope” of an X12 837 (4010) professional claim file. Together, they define the start and end of the interchange and ensure that the data between them is processed as a single unit. The ISA establishes sender/receiver details, control numbers, delimiters, and usage indicators, while the IEA closes the interchange and provides the count of functional groups inside.
The ISA/IEA pair is mandatory and always appears exactly once per interchange. Because the ISA segment is fixed length, each data element must be padded to its required length (for example, ISA06 and ISA08 must be exactly 15 characters). Any mismatch between ISA13 and IEA02 or incorrect padding will cause interchange rejections.
Sample 837P (4010) – ISA / IEA Interchange Control Envelope
- ISA*00* *00* *ZZ*SENDERID *ZZ*RECEIVERID *250918*0535*U*00401*000000011*1*P*:~
-
GS*HC*SENDERCODE*RECEIVERCODE*20250918*0535*10022*X*004010X098A1~
- ST*837*0001~
- ... (claims detail segments) ...
- SE*39*0001~
GE*1*10022~ - IEA*1*000000011~
In this example:
- ISA13 – Interchange Control Number is
000000011, which matches IEA02 at the end. - IEA01 – Contains the count of functional groups (GS/GE pairs) in this interchange (here,
1). - IEA02 – Must exactly match ISA13, forming a control pair to validate file integrity.
Reminder: The ISA/IEA envelope should always properly match. Many clearinghouses will reject an entire interchange if the control number sequence is out of sync or if IEA01 does not reflect the correct count of GS segments.
HIPAA Guide – 837P [4010]
[Mandatory]
| Segment | Field | Name | Definition | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ISA | 01 | Authorization Information Qualifier |
Usually 00 when not used.
|
||||||||||||||||||||
| ISA | 02 | Authorization Information | 10 characters; blank-padded when not used. | ||||||||||||||||||||
| ISA | 03 | Security Information Qualifier |
|
||||||||||||||||||||
| ISA | 04 | Security Information | 10 characters; blank-padded when not used. | ||||||||||||||||||||
| ISA | 05 | Interchange ID Qualifier (Sender) |
Qualifier for ISA06 (Sender ID).
|
||||||||||||||||||||
| ISA | 06 | Interchange Sender ID | 15 characters, left-justified and space-padded. | ||||||||||||||||||||
| ISA | 07 | Interchange ID Qualifier (Receiver) |
Qualifier for ISA08 (Receiver ID).
|
||||||||||||||||||||
| ISA | 08 | Interchange Receiver ID | 15 characters, left-justified and space-padded. | ||||||||||||||||||||
| ISA | 09 | Interchange Date | Date the file was created, format YYMMDD (e.g., 250918). | ||||||||||||||||||||
| ISA | 10 | Interchange Time | Time the file was created, format HHMM (e.g., 0535). | ||||||||||||||||||||
| ISA | 11 | Interchange Control Standards Identifier |
|
||||||||||||||||||||
| ISA | 12 | Interchange Control Version Number | 00401 for X12 4010. | ||||||||||||||||||||
| ISA | 13 | Interchange Control Number | 9-digit control number; must match IEA02 exactly. | ||||||||||||||||||||
| ISA | 14 | Acknowledgment Requested |
|
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| ISA | 15 | Usage Indicator |
|
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| ISA | 16 | Component Element Separator | Single character used to separate sub-elements (e.g., :). | ||||||||||||||||||||
| IEA | 01 | Number of Included Functional Groups | Count of GS/GE pairs within the interchange (e.g., 1). | ||||||||||||||||||||
| IEA | 02 | Interchange Control Number | Must equal ISA13 to confirm envelope integrity (e.g., 000000011). |
Note: The ISA and IEA segments form a matched pair. ISA13 and IEA02 must always match, and IEA01 must equal the number of GS segments between ISA and IEA. Always validate these when troubleshooting rejected EDI files.
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