UDI Differences – Comparison between US and EU

UDI Unterschiede in EU & US

On September 24, 2013, a directive was passed in the United States to introduce an identification system for MedTech products, which came into force on December 23 of the same year. It comes in the form of the Unique Device Identifier (UDI) and is intended to simplify the tracking of medical devices sold in the United States. In April 2017, the European Union followed suit with the Medical Device Regulation (MDR) and the In-vitro Diagnostic Regulation (IVDR). The EU-MDR came into force on June 21, 2017. They define the conditions for the EU’s UDI system. The requirements of the respective markets/regions are not uniform, making 1-to-1 implementation between regions impossible for medical device manufacturers.

Despite efforts to implement uniform standards for the UDI worldwide, the requirements in the U.S. and the EU differ in many ways. Differences within the two regulations relate to compliance dates, product classification, databases used, and required product data. In addition, the European Union has also introduced the Basic UDI-DI for identifying similar products of a manufacturer, which does not exist in the US.

Product classification and compliance dates

There is a difference between the regions’ product classes. In the EU, there are classes I, IIa, IIb, III, and reusable as well as implantable devices. The FDA’s Center for Devices and Radiological Health (CDRH) distinguishes between classes I, II, III, and LS/LS. Each class has its date for mandatory application of the regulations, depending on the region.


EU-UDI Compliance Dates

Class IIIMay 26, 2021
Class IIa & IIbMay 26, 2023
Class IMay 26, 2025

Compliance dates for UDI regulations in the European Union

US-UDI Compliance Dates

LS/LSSeptember 24, 2015
Class IIISeptember 24, 2016
Class IISeptember 24, 2018
Class I & unclassified
medical devices
September 24, 2020

Compliance dates for UDI regulations in the United States

The databases: EUDAMED and GUDID

Both regulations require manufacturers to store information about their medical devices in a database. This makes them identifiable and traceable. In the USA, this database is called the Global Unique Device Identification Database (GUDID), while the European equivalent is called the European Database on Medical Devices (EUDAMED). The EUDAMED consists of 6 modules that are connected. The GUDID, on the other hand, is structured as an independent database.

There are different formats for data exchange, depending on the database. The EU uses Extensible Markup Language (XML), while the U.S. uses Health Level 7 (HL7) Structured Product Labeling (SPL). The FDA allows XML files to be submitted, but not as a bulk upload. Instead, manufacturers can only upload individual device identifiers. These must also be adapted to the HL7-SPL.

How do the European and US UDI differ?

The UDI is a numeric or alphanumeric code for identifying medical devices. It consists of the UDI Device Identifier (UDI-DI) and the UDI Product Identifier (UDI-PI). The UDI-DI is a unique code and is used for item identification. In addition, it provides access to the respective database in which the product data and, if applicable, other documents are stored. For the American database, there are 28 required, 24 conditionally required, and 15 optional product attributes stored. For the European database, depending on the type of product, there are 59 required, 20 conditionally required, and 5 optional specifications. 

The structure of the UDI from the USA and the EU is indistinguishable. On the products, they consist of machine-readable and human-readable parts. Machine-readable means that it may be a linear barcode or a 2D barcode. For humans, the code consists of numeric/alphanumeric UDI-DI and UDI-PI. The UDI-PI may include lot number, serial number, expiration date, and production date, thereby enabling traceability of an individual medical device. Furthermore, the UDI-DI serves as a link to the EUDAMED (EU) and GUDID (US) databases and is thus, the access key to the information stored there. In the European Medical Device Regulation (MDR) a distinction is also made between Basic UDI-DI and UDI-DI. Although the UDIs have the same structure, they cannot be used parallel for both regulations.

Basic UDI-DI: Newly introduced with EU MDR

In addition to the UDI-DI, the EU has introduced another, superordinate identifier. The Basic UDI-DI. While the regulation for the United States only requires the assignment of the UDI-DI itself, the Basic UDI-DI is additionally required in the EU. It does not identify a single product but serves as a parent category for various products of a category that share certain characteristics. An example: A manufacturer wants to produce a medical thermometer in three different versions. A yellow one, a red one, and a blue one. Each of the three thermometers is given its UDI-DI. However, these three versions of the thermometer share a single Basic UDI-DI because they belong to the same category. In contrast, in the U.S., each thermometer would only receive its UDI-DI and the grouping under the Basic UDI-DI would not apply.

The differences shown here are not exhaustive but are intended to provide an overview. Special attention should be paid to the file formats of the databases, the differences of possible product data, and the EU’s Basic UDI-DI. Implementation of these different regulations seems intimidating at first due to their amount. That’s why it can make sense to enlist the help of an external service provider to support the company in implementing them correctly. In this way, problems can be avoided right from the start.

Compliance datesSee aboveSee above
Data formatXMLHL7-SPL
Responsibility for
assigning UDI
Data base access keyBasic UDI-DIUDI-DI
Possible UDI-DI
product data
Data base structure6 different modulesStand alone, exclusively
for UDI

UDI differences in EU- and US

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