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HL7 v2Segment5 min read

HL7 IIM Segment: Inventory Item Master

Overview

The IIM (Inventory Item Master) segment carries the master record for a stocked inventory item. It identifies the item with a primary key, ties it to a service item code, and captures lot, expiration, location, manufacturer, receipt, and on-hand information for the item as held by the reporting organization.

IIM is the payload segment of master-file notifications that publish or update inventory item master data between systems — typically a materials management system feeding clinical and billing systems with the authoritative catalog of stocked items.

Used In

IIM provides the inventory item master record carried in MFN^M16 (Master File Notification — Inventory Item Master) messages. The message wraps each IIM in the standard master-file framing (MSH, MFI, MFE) so that receivers can add, update, or deactivate items in their local inventory catalog. See MFN — Master File Notification messages for the surrounding message context.

Field-by-Field Reference

Each field below follows the v2.5.1 definition published in the HAPI javadoc for the IIM segment. Sequence numbers correspond to the field positions encoded in the pipe-delimited segment. Required fields must be present in any conformant instance; optional fields may be omitted. Data type links point to the v2.5.1 data type references on the Vorro HL7 Academy.

SeqNameData TypeLengthReqRepeatTable #Description
IIM-1Primary Key Value - IIMcweRUnique identifier of the inventory item
IIM-2Service Item CodecweOService or charge code tied to the item
IIM-3Inventory Lot NumberstOManufacturer lot number for the stock
IIM-4Inventory Expiration DatetsOExpiration date of the stocked lot
IIM-5Inventory Manufacturer NamecweOManufacturer of the stocked item
IIM-6Inventory LocationcweOStorage location where stock is held
IIM-7Inventory Received DatetsODate the stock was received
IIM-8Inventory Received QuantitynmOQuantity received at time of receipt
IIM-9Inventory Received Quantity UnitcweOUnit of measure for received quantity
IIM-10Inventory Received Item CostmoOPer-unit cost at time of receipt
IIM-11Inventory On Hand DatetsODate the on-hand quantity was counted
IIM-12Inventory On Hand QuantitynmOCurrent quantity on hand at location
IIM-13Inventory On Hand Quantity UnitcweOUnit of measure for on-hand quantity
IIM-14Procedure CodeceOProcedure code associated with the item
IIM-15Procedure Code ModifierceOYModifier qualifying the procedure code

Examples

Minimal IIM

IIM|ITEM-77231^Sterile Saline 0.9% 1000mL^VORRO-CAT

Fully populated IIM

IIM|ITEM-77231^Sterile Saline 0.9% 1000mL^VORRO-CAT|CHG-44120^IV Solution Saline 1L^VORRO-CDM|LOT-SA-9914|20271031000000|MFG-BAXTR^Baxter Healthcare^MFG|LOC-PHY-CSTOR-04^Central Sterile Storage^VORRO-LOC|20260520093000|240|EA^Each^HL70530|3.42^USD|20260615060000|186|EA^Each^HL70530|96374^Therapeutic IV Infusion^C4|59^Distinct Procedural Service^HL70340

Annotated breakdown

IIM                                                       Segment ID
|ITEM-77231^Sterile Saline 0.9% 1000mL^VORRO-CAT          IIM-1  Primary Key Value (CWE)
|CHG-44120^IV Solution Saline 1L^VORRO-CDM                IIM-2  Service Item Code (CWE)
|LOT-SA-9914                                              IIM-3  Inventory Lot Number
|20271031000000                                           IIM-4  Inventory Expiration Date
|MFG-BAXTR^Baxter Healthcare^MFG                          IIM-5  Manufacturer Name (CWE)
|LOC-PHY-CSTOR-04^Central Sterile Storage^VORRO-LOC       IIM-6  Inventory Location (CWE)
|20260520093000                                           IIM-7  Inventory Received Date
|240                                                      IIM-8  Inventory Received Quantity
|EA^Each^HL70530                                          IIM-9  Received Quantity Unit (CWE)
|3.42^USD                                                 IIM-10 Inventory Received Item Cost (MO)
|20260615060000                                           IIM-11 Inventory On Hand Date
|186                                                      IIM-12 Inventory On Hand Quantity
|EA^Each^HL70530                                          IIM-13 On Hand Quantity Unit (CWE)
|96374^Therapeutic IV Infusion^C4                         IIM-14 Procedure Code (CE)
|59^Distinct Procedural Service^HL70340                   IIM-15 Procedure Code Modifier (CE, repeats)

In-context excerpt — MFN^M16 inventory item master file

MSH|^~&|MATERIALS|VORRO-MM|PHARMACY|VORRO-PHX|20260616071200||MFN^M16^MFN_M16|MSG00120341|P|2.5.1
MFI|INV^Inventory Master^HL70175|||UPD|20260616071200|NE
MFE|MUP|EVT-99812||ITEM-77231|CWE
IIM|ITEM-77231^Sterile Saline 0.9% 1000mL^VORRO-CAT|CHG-44120^IV Solution Saline 1L^VORRO-CDM|LOT-SA-9914|20271031000000|MFG-BAXTR^Baxter Healthcare^MFG|LOC-PHY-CSTOR-04^Central Sterile Storage^VORRO-LOC|20260520093000|240|EA^Each^HL70530|3.42^USD|20260615060000|186|EA^Each^HL70530

In-context excerpt — new item added with procedure linkage

MSH|^~&|MATERIALS|VORRO-MM|BILLING|VORRO-PB|20260617153045||MFN^M16^MFN_M16|MSG00120512|P|2.5.1
MFI|INV^Inventory Master^HL70175|||UPD|20260617153045|NE
MFE|MAD|EVT-99840||ITEM-88044|CWE
IIM|ITEM-88044^Infusion Pump Set 60in^VORRO-CAT|CHG-44210^IV Admin Set^VORRO-CDM|LOT-IP-2240|20280215000000|MFG-BBRAN^B. Braun Medical^MFG|LOC-PHY-OR-MAIN^OR Main Supply^VORRO-LOC|20260612101500|50|EA^Each^HL70530|7.85^USD|20260616180000|46|EA^Each^HL70530|96365^IV Infusion Initial^C4|59^Distinct Procedural Service^HL70340

Notes and Best Practices

  • IIM-1 (Primary Key Value) must be present and stable across updates; receivers key all subsequent MFN actions (MAD, MUP, MDL) on this identifier via the paired MFE-4 entry.
  • Pair IIM-3 (Lot Number) with IIM-4 (Expiration Date) for any lot-tracked item; downstream barcode and recall workflows rely on the combination.
  • Quantity and Unit fields travel in matched pairs: IIM-8 with IIM-9 for received, IIM-12 with IIM-13 for on-hand. Send the unit even when it appears redundant — receivers normalize across catalogs.
  • IIM-10 uses the MO (Money) data type — encode currency in the second component so multi-currency receivers can interpret the amount correctly.
  • IIM-15 is the only repeating field; repeat modifiers in the order they should apply to the procedure code in IIM-14.
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HL7 IIM Segment: Inventory Item Master | Vorro Academy | Vorro