MSH - Message header segment (HL7 v2.3)
Versions: v2.3 v2.3.1 v2.4 v2.5.1 v2.6 v2.7.1
The MSH segment (Message header segment) has 19 fields in HL7 v2.3. Fields are addressed as
MSH-n; composite fields break into components MSH-n.m. Paste a message into the
parser to see every field annotated with this table.
| # | Name | Type | Len | Opt | Repeats | Table |
|---|---|---|---|---|---|---|
| 1 | Field Separator | ST | 1 | Required | No | |
| 2 | Encoding Characters | ST | 4 | Required | No | |
| 3 | Sending Application | HD | 180 | Optional | No | |
| 4 | Sending Facility | HD | 180 | Optional | No | |
| 5 | Receiving Application | HD | 180 | Optional | No | |
| 6 | Receiving Facility | HD | 180 | Optional | No | |
| 7 | Date / Time of Message | TS | 26 | Optional | No | |
| 8 | Security | ST | 40 | Optional | No | |
| 9 | Message Type | CM_MSG | 7 | Required | No | |
| 10 | Message Control ID | ST | 20 | Required | No | |
| 11 | Processing ID | PT | 3 | Required | No | |
| 12 | Version ID | ID | 8 | Required | No | 0104 |
| 13 | Sequence Number | NM | 15 | Optional | No | |
| 14 | Continuation Pointer | ST | 180 | Optional | No | |
| 15 | Accept Acknowledgement Type | ID | 2 | Optional | No | 0155 |
| 16 | Application Acknowledgement Type | ID | 2 | Optional | No | 0155 |
| 17 | Country Code | ID | 2 | Optional | No | |
| 18 | Character Set | ID | 6 | Optional | No | 0211 |
| 19 | Principal Language of Message | CE | 3 | Optional | No |
Synthetic example
MSH|^~\&|PAS|NORTHSIDE|INTAKE|BASAL|20260823093000+1000||ADT^A01^ADT_A01|NS20260823093000001|P|2.5.1|||AL|NE|AU