Medical Device UDI Compliance: Requirements by Device Class

What Is the UDI System?

The Unique Device Identification (UDI) system is an FDA-mandated identification framework that assigns a unique code to every medical device distributed in the United States. Established by the FDA UDI Rule (September 24, 2013) under Section 519(f) of the FD&C Act and codified at 21 CFR Part 830, the UDI system is designed to improve patient safety, enable more accurate adverse event reporting, and facilitate efficient device recalls.

The UDI appears as a barcode (or RFID tag) on the device label and packaging, readable by both humans and machines. It consists of two components:

• Device Identifier (DI): A fixed, mandatory portion that identifies the specific version or model of a device and its labeler. The DI is assigned by an FDA-accredited issuing agency (GS1, HIBCC, or ICCBBA).
• Production Identifier (PI): A variable portion that identifies one or more of the following: lot or batch number, serial number, expiration date, and manufacturing date. Which PI elements are required depends on the device and how it is labeled.

Together, the DI and PI create a globally unique identifier that can trace a specific device unit from the manufacturer through the supply chain to the patient.

UDI Requirements by Device Class

FDA phased in UDI compliance over several years based on device classification risk level. As of 2026, all classes must comply:

Direct marking means permanently marking the UDI directly on the device itself (not just the packaging). This is required for devices intended to be reprocessed and reused, and for implantable devices. The direct mark must remain readable through the device's expected service life.

The GUDID Database

The Global Unique Device Identification Database (GUDID) is FDA's publicly accessible database of UDI information. Every device marketed in the U.S. with a UDI must have its DI-level information submitted to GUDID. GUDID does not store production-level (PI) data.

GUDID submissions include:

• Device Identifier (DI) and issuing agency
• Device brand name and model number
• Company name and contact information
• Device description, including intended use
• Device classification (product code, class, regulation number)
• Whether the device contains natural rubber latex or MRI safety information
• Sterilization status and method
• Device packaging information (number of devices per package)
• Premarket submission numbers (510(k), PMA, De Novo, HDE)

Submissions are made through the GUDID web interface or through the Health Level 7 (HL7) SPL data exchange standard for bulk uploads. GUDID entries must be updated within 10 business days of any change to the recorded information (21 CFR §830.60).

GUDID data is publicly searchable through FDA's AccessGUDID portal, which healthcare providers, hospitals, and supply chain managers use to identify and verify medical devices.

UDI Labeling Requirements

The UDI must appear on both the device label and the device package in two forms:

• Human-readable (plain text): The UDI must be printed in a format that can be read without any technology
• AIDC (Automatic Identification and Data Capture): A machine-readable format such as a barcode, 2D matrix code, or RFID tag that conforms to an FDA-accredited issuing agency's standard

Specific labeling considerations include:

• Each packaging level must bear the appropriate UDI. A device inside a carton inside a case results in three different UDIs (device-level DI, carton-level DI, case-level DI).
• For devices where a label is on the individual device (e.g., a syringe), both the device label and the package must bear the UDI.
• Combination products where the device component is the primary mode of action follow device UDI requirements.
• Custom-made devices (e.g., patient-matched implants) have the same UDI requirements but may use individual serial numbers as the PI.

Mislabeled UDIs or missing UDI information can result in FDA warning letters, import refusals, and mandatory recalls. Verification of UDI accuracy should be part of your final labeling quality check before distribution.

Common UDI Compliance Mistakes

Based on FDA inspection findings and warning letter data, these are the most common UDI compliance failures:

• Missing GUDID submissions. Some manufacturers apply UDI barcodes to labels but fail to submit the corresponding DI data to GUDID. A UDI barcode without GUDID entry is non-compliant.
• Incorrect barcode format. Using a barcode format not recognized by your designated issuing agency (GS1, HIBCC, or ICCBBA) renders the AIDC non-compliant.
• Missing Production Identifier elements. Failing to include required PI elements (lot number, expiration date, etc.) in the UDI when the device label already shows them.
• Not updating GUDID after changes. When device specifications, labeling, or company information changes, GUDID must be updated within 10 business days.
• Direct marking failures. Reusable devices and implants must have permanent direct marks that survive sterilization and reprocessing. Marks that fade, smear, or become unreadable are non-compliant.
• Incorrect packaging hierarchy. Multi-level packages need UDIs at each level. Missing UDIs on outer cartons or cases is a frequently cited violation.

UDI and International Harmonization

The UDI system is part of a global effort to harmonize medical device identification. The International Medical Device Regulators Forum (IMDRF) published UDI guidance that many countries are adopting:

• EU MDR/IVDR: The European Union requires UDI under the Medical Device Regulation (EU 2017/745) and In Vitro Diagnostic Regulation (EU 2017/746), with EUDAMED serving a role similar to FDA's GUDID.
• South Korea (MFDS) has implemented UDI requirements for medical devices since 2019, using GS1 and HIBCC standards.
• Saudi Arabia (SFDA) adopted UDI requirements aligned with IMDRF guidance effective 2021.

For manufacturers selling globally, using a single issuing agency (GS1 is the most widely accepted) and maintaining consistent DI assignments across markets can simplify multi-jurisdiction compliance. Your FDA US Agent for medical devices can help coordinate UDI compliance as part of your U.S. market registration.