| SEQ | SEGMENT |
| 1 | ACC - Accident |
| 2 | ADD - Addendum |
| 3 | BHS - Batch Header |
| 4 | BLG - Billing |
| 5 | BTS - Batch Trailer |
| 6 | DG1 - Diagnosis |
| 7 | DSC - Continuation Pointer |
| 8 | DSP - Display Data |
| 9 | ERR - Error |
| 10 | EVN - Event Type |
| 11 | FHS - File Header |
| 12 | FT1 - Financial Transaction |
| 13 | FTS - File Trailer |
| 14 | GT1 - Guarantor |
| 15 | IN1 - Insurance |
| 16 | MRG - Merge Patient Information |
| 17 | MSA - Message Acknowledgment |
| 18 | MSH - Message Header |
| 19 | NCK - System Clock |
| 20 | NK1 - Next Of Kin |
| 21 | NPU - Non-patient Update |
| 22 | NSC - Status Change |
| 23 | NST - Statistics |
| 24 | NTE - Notes And Comments |
| 25 | OBR - Observation Request |
| 26 | OBX - Result |
| 27 | ORC - Common Order |
| 28 | ORO - Order Other |
| 29 | PD1 - Patient Demographics |
| 30 | PID - Patient Identification |
| 31 | PR1 - Procedures |
| 32 | PV1 - Patient Visit |
| 33 | QRD - Query Definition |
| 34 | QRF - Query Filter |
| 35 | RX1 - Pharmacy Order |
| 36 | UB1 - Ub82 Data |
| 37 | URD - Results/update Definition |
| 38 | URS - Unsolicited Selection |