OMP^O09 — Pharmacy / Treatment Order

CPOE prescribes, pharmacy validates: OMP^O09 carries the complete medication order with the route / posology / components triple (for IV solutions and mixes).

Purpose

OMP is the CPOE → pharmacy pivot: it carries the medical order in structured rather than encoded form (unlike OMR/RDE which use RXE for already-encoded/dispensed orders). Loop: one PID + PV1 + multiple (ORC, RXO, RXR ×*, RXC ×*) for multiple prescription lines.

Segment structure

Structure OMP_O09: MSH, PID, [PV1], then the Order block repeated: ORC + RXO + [RXR…] + [RXC…] + [OBX…].

• ORC: Common Order — function code (NW=New, RP=Reprint, RU=Replace, DC=Discontinue).
• RXO: Pharmacy Order — drug, requested dose, unit, form.
• RXR: Route — route (PO, IV, IM, SC, SL…) and site.
• RXC: Component — for compounded solutions (IV additives, mixes).

Real-world example

Amoxicillin 500mg PO TID prescription:

MSH|^~\&|CPOE|HOSP01|SIP|HOSP01|20260516161500||OMP^O09^OMP_O09|MSG00090001|P|2.5.1|||AL|NE
PID|1||MRN567890^^^HOSP^MR||DOE^JOHN^A^^MR.||19720515|M
PV1|1|I|MED^205^A^HOSP01|EM|||DRSMITH|||MED|||1|||DRSMITH|ADM|||||||||||||||||||HOSP01
ORC|NW|ORD12345^CPOE|||SC|||||DRSMITH^Smith^James^A^^DR.
RXO|001234^AMOXICILLIN 500MG^NDC|500||MG|TAB|||||||||||||3
RXR|PO^ORAL
RXC|B|001234^AMOXICILLIN 500MG^NDC|500|MG

Acknowledgment

MSH|^~\&|SIP|HOSP01|CPOE|HOSP01|20260516161501||ACK^O09^ACK|ACK00090001|P|2.5.1
MSA|AA|MSG00090001

Common errors

• ORC without valid NW/RP/DC: pharmacy cannot tell if this is a new prescription, reprint, or cancellation.
• RXO without RXR: route unspecified — pharmacist must call the prescriber. Always provide the route.
• Malformed NDC: HL7 expects 10-digit NDC in RXO-1.3=NDC. Leading-zero 11-digit NDCs break some parsers.
• OMP / RDE confusion: OMP = raw order, RDE = order encoded for dispensation. A modern EHR sends OMP, the pharmacy returns RDS when dispensed.

Related messages

See also: RDE^O11, RDS^O13, RAS^O17.