FAQ on UDI, Part 1: Facts About the Unique Device Identification Directive

Following the Unique Device Identification directive (UDI), mandated by the Food & Drug Administration (FDA), medical devices have to be clearly identified to ensure traceability and patient safety. The rule-compliant implementation challenges medical device manufacturers and raises many questions.

Laserbeschriftung medizinischer Instrumente mit UDI Code (Skalpellhalter)

What is the reason for the implementation of UDI?

The UDI system addresses all of the following aspects:

  • More efficient product recalls.
  • Improved counterfeiting protection.
  • Simplification of data entry and accessibility with different systems.
  • Security throughout the entire supply chain.
  • Field Safety Corrective Action – FSCA.
  • Better identification, documentation and prevention of incidents.
  • Prevent medical errors from occurring.

Additionally, the labeling system enables the simplification of logistics, ordering and delivery processes.

UDI in the U.S. and in Europe: Where does the directive apply?

The goal of the UDI system is to increase patient safety and to allow for a sustainable traceability. The FDA-directive applies to medical devices that are produced or imported and are distributed in the U.S. Equivalent directives are being introduced internationally: The European Union has just released a resolution on UDIs within the Medical Device Regulation (MDR), becoming effective gradually from 2020 on.

Both systems have in common the central allocation and registration of product numbers in a common database. The center of the American UDI system is the “Global Unique Device Identification Database” (GUDID), which acts as a registry and as a reference catalog for every device with an identifier. The European equivalent is EUDAMED (European Database on Medical Devices).


What is the structure of a UDI code?

UDI codes consist of a Device Identifier (DI) and a Production Identifier (PI), the first of which identifies the manufacturer/labeler and the specific version or model of the device (also reference code). The Device Identifier is a globally unique product code which allows the clear identification of a device and must be entered in the central registry. The Production Identifier is optional and represents the variable portion of a UDI that identifies variables like the lot and batch numbers, serial numbers, expiration or manufacturing dates etc.

According to 21 CFR 801.40, medical devices have to carry a UDI that is represented in two forms:

  • Easily readable plain-text (HRI/Human Readable Interpretation), alpha-numeric characters
  • AIDC technology (Automatic Identification and Data Capture), which means a machine readable code (barcode/2D code)

In case the UDI code is applied as a permanent direct mark, it must be in either or both (1) easily readable plain-text and (2) AIDC form or alternative technology (see 21 CFR 801.45).

UDI marking on stainless steel umbilical cord scissor. Marking procedure: Annealing with a fiber laser marker.

GS1, HIBC, ICCBBA: Which code is suitable for UDI marking?

The FDA has accredited three organizations as UDI issuing agencies: GS1, HIBCC (Health Industry Business Communications Council) and ICCBBA (International Council for Commonality in Blood Banking Automation). Both the Health Industry Bar Code (HIBC) and the GS1 code are equally suitable for the UDI compliant marking of medical products and devices. The ICCBBA UDI code, as approved by the FDA, is best adapted to identify products of human origin (like plasma or transplants).

UDI codes are graphically depicted in an assembly of two forms: a human readable plain text of alpha-numeric characters and a machine-readable code (see above). There are different forms of machine readable codes available: The GS1-128 linear bar code, the GS1 data matrix code from GS1, the HIBC linear bar code and the HIBC data matrix code, and the linear ISBT 128 and 2D code from ICCBBA. Depending on the accredited issuing agency, each product can receive its unique code in any of the above formats.

UDI code examples

Which technology is suitable for UDI-compliant marking?

One of the major challenges facing UDI is the implementation of the appropriate direct marking technology. The FDA does not specify which of the various available options should be used. Moreover, not every method is suitable for secure and UDI-compliant direct part marking; therefore choosing the best method to meet the requirements can be difficult and is crucial.

Laser marking is ideally suited for the direct marking of medical devices with the Unique Device Identifier. It fulfills all the criteria relevant for safe product marking based on medical standards and UDI requirements. The laser produces high-quality, permanent, readable markings on products as well as packaging and ensures the highest precision and process stability when combined with integrated vision systems.