Guide · Unique Device Identification
UDI barcode format, explained
A UDI has two parts: the device identifier (DI), which names the model, and production identifiers (PI) such as lot, serial number, expiration and manufacture dates. In the GS1 system each piece follows an application identifier in brackets: (01) for the 14-digit GTIN that serves as the DI, (17) for expiration date as YYMMDD, (10) for lot, (21) for serial and (11) for manufacture date. For example (01)00614141123452(17)271231(10)LOT4821(21)SN000193.
A UDI, decoded
This example is decoded by the same parser as UDIScope:
(01)00614141123452(17)271231(10)LOT4821(21)SN000193
| AI | Meaning | Value |
|---|---|---|
| (01) | Global Trade Item Number (GTIN / UDI-DI) | 00614141123452 |
| (17) | Expiration Date (YYMMDD) | 2027-12-31 |
| (10) | Batch or Lot Number | LOT4821 |
| (21) | Serial Number | SN000193 |
The device identifier is 00614141123452. Its last digit, 2, is a GS1 modulo-10 check digit computed from the other 13: it checks out. The production identifiers are lot LOT4821, serial SN000193 and expiration date 2027-12-31. The company prefix 0614141 is the one GS1 uses in its own documentation, so the example identifies no real product.
The two parts: DI and PI
The device identifier (DI) is fixed for a version or model and is the key into FDA's GUDID database. The production identifiers (PI) change from unit to unit or lot to lot: lot or batch, serial number, manufacture date, expiration date and, for some products, a distinct identification code.
Dates in GS1 barcodes are six digits, YYMMDD. On the human-readable label, FDA requires dates in the year-month-day form, for example 2027-12-31 (21 CFR 801.18).
The GS1 application identifiers you will see
| AI | Field | Format |
|---|---|---|
| (01) | GTIN, the device identifier | 14 digits, last is a check digit |
| (11) | Manufacture date | 6 digits, YYMMDD |
| (17) | Expiration date | 6 digits, YYMMDD |
| (10) | Lot or batch | Up to 20 characters |
| (21) | Serial number | Up to 20 characters |
In the barcode itself the brackets are not encoded: fixed-length fields run on, and a variable-length field such as lot or serial is ended by a separator character when another field follows it. The brackets appear only in the human-readable text.
Who issues UDIs
FDA-accredited issuing agencies: GS1, HIBCC (Health Industry Business Communications Council) and ICCBBA. Each has its own format; GS1 is the most common for devices. An HIBCC UDI starts with a plus sign; an ICCBBA one is used mainly for products of human origin.
Check one yourself
Check that each application identifier carries a value of the right length, that the GTIN check digit is correct (GS1 modulo-10), that dates are real calendar dates, and that the DI resolves to a record in GUDID. UDIScope does all four from a pasted or scanned string. To lay out a label with compliant UDI barcodes, use MedLabel Studio; to turn a UDI into an HL7 FHIR Device resource, use FHIRBridge MD.