^O01
ORM^O01 — General Order Message
The ORM^O01 is the legacy general order message used to communicate clinical orders from an ordering system to a fulfillment system. It carries the order details, ordering provider, and patient context.
When Is This Sent?
When a clinician places an order in the CPOE or ordering system for radiology, lab, pharmacy, or other ancillary services. Also sent for order status changes (cancel, modify).
Real-World Usage
ORM^O01 remains the dominant order message in many hospital HL7 interfaces despite being officially superseded by newer message types. Most PACS and RIS systems have been configured for years to receive ORM^O01. The procedure code in OBR.4 must match the receiving system's procedure catalog — this is the most common source of rejected orders.
Message Structure
Segment names link to their field-level reference pages.
| # | Segment | Purpose in this message | Req | Repeat |
|---|---|---|---|---|
| 1 | MSH | Message header with ORM^O01 in MSH.9 | R | — |
| 2 | PID | Patient demographics | R | — |
| 3 | ORC | Order control — ORC.1 specifies action (NW=New, CA=Cancel, XO=Change) | R | — |
| 4 | OBR | Order details including procedure code (OBR.4) and requesting provider | R | — |
| 5 | EVN | Event type (sometimes included) | O | — |
| 6 | PV1 | Patient visit context (inpatient/outpatient) | O | — |
| 7 | NTE | Clinical notes and order instructions | O | Yes |
| 8 | DG1 | Ordering diagnosis (clinical indication) | O | Yes |
| 9 | OBX | Pre-existing observations (e.g., height/weight for certain procedures) | O | Yes |
Example Message
Realistic example with fake patient data. Paste into the HL7 Message Viewer to explore interactively.
1MSH||^~\&|EPIC|HOSPITAL_A|MIRTH_PROD|RIS|20260310143205||ORM^O01^ORM_O01|ORD00001|P|2.5.1 2PID||1||123456^^^HOSP_A^MR||Smith^John^M^^Mr.||19850315|M 3PV1||1|I|4A^201^1^^^HOSP_A||||1234^Ahmed^Dr.^Khalid 4ORC||NW|ORD20260310001^EPIC|ACC20260310001^RIS||SC||^^^20260310143000^^R||20260310143205|1234^Ahmed^Dr.^Khalid 5OBR||1|ORD20260310001^EPIC|ACC20260310001^RIS|71046^Chest 2 Views^CPT4|||20260310143205|||||||||1234^Ahmed^Dr.^Khalid|||||ACC20260310001||RAD
Troubleshooting Scenarios
Order not appearing in PACS/RIS after placement
Cause
Procedure code in OBR.4 doesn't match the receiving system's procedure catalog. This is the #1 cause of rejected orders.
Fix
Obtain the exact procedure code format expected by the RIS/PACS. Check: (1) code system (CPT4, local, LOINC), (2) code format (with or without decimal), (3) code itself. Build a procedure code crosswalk if needed.
Order cancel not processed by receiving system
Cause
ORC.1=CA (cancel request) is sent but the receiving system only responds to OC (order cancelled notification).
Fix
Check receiving system documentation for cancel handling. Some systems require ORC.1=CA AND ORC.5=CA. Others use a completely different control code. Verify with the vendor.
Common Confusions
ORM^O01 (legacy) vs OMG^O19 (newer). ORM^O01 is still widely used in practice. OMG^O19 is the recommended replacement per IHE Scheduled Workflow profile but requires both sides to support it. Most existing PACS/RIS interfaces use ORM^O01. Use OMG^O19 only when both sending and receiving systems explicitly support IHE SWF.
Related Message Types
Segment Reference
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