Skip to main content
v2026.11,772 entries · CC-BY 4.0

UDI Medical Device: FDA Unique Device Identifier Requirements Explained

What a medical device UDI is, the FDA rule (21 CFR Part 830) and GUDID database behind it, who issues device identifiers, and why procurement and supply-chain systems rely on it.

Written and maintained by CASRAI Editorial Board

Last updated

A UDI (Unique Device Identifier) is a code, in both plain-text and machine-readable (barcode or RFID) form, that a medical device labeler assigns to identify a device through distribution and use. LAC Health’s glossary carries a shorter FDA UDI / GUDID reference for buyers checking a device’s identifier. In the United States it is required under the FDA’s Unique Device Identification System, codified primarily at 21 CFR Part 830, with device labeling requirements in 21 CFR 801 Subpart B. For research administrators, lab managers, and procurement/supply-chain staff, UDI matters less as a labeling technicality and more as the identifier system that lab and hospital purchasing, inventory, and recall-tracking systems now build on.

What a UDI actually contains

Every UDI has two parts:

  • Device Identifier (DI) — a fixed, mandatory segment that identifies the labeler (manufacturer) and the specific version or model of a device. The DI does not change unless the device’s labeling changes in a way that affects its intended use, performance, or safety.
  • Production Identifier (PI) — one or more variable segments identifying, where applicable: lot or batch number, serial number, expiration date, date of manufacture, and, for human cells, tissues, and cellular and tissue-based products (HCT/Ps), a distinct identification code.

Together, DI+PI let a specific unit of a specific device be traced from manufacture through a specific patient or point of use — the same DI/PI split that underlies most modern medical-device recall and adverse-event tracing.

Who issues UDIs and how they’re structured

Labelers don’t invent their own numbering scheme. They obtain DIs through one of the FDA-accredited issuing agencies, each of which operates its own numbering standard:

  • GS1 — issues GTIN-based device identifiers, the same organization behind retail/supply-chain barcoding generally.
  • HIBCC (Health Industry Business Communications Council) — issues Health Industry Bar Code (HIBC) identifiers, historically common for surgical and lab-supply items.
  • ICCBBA — issues ISBT 128 identifiers, used primarily for blood, tissue, and cellular therapy products.

The barcode or RFID tag on a device’s label encodes the UDI in one of these standards’ symbologies, so the same physical scanner/parsing logic used for general lab and inventory barcoding (see our guide on barcode and RFID labeling for lab sample and inventory tracking) can typically read a UDI carrier as well, provided the receiving system is configured to parse GS1/HIBC/ISBT syntax correctly.

GUDID: the public UDI database

Labelers submit device records to the FDA’s Global Unique Device Identification Database (GUDID), the reference database of DI records (not PI — GUDID holds device-level data, not unit-level lot/serial tracking). GUDID data is publicly searchable through AccessGUDID, hosted by the National Library of Medicine. A GUDID record typically includes the DI, brand name, device description, labeler (company) name, FDA product code, whether the device is sterile/single-use/an implant/an MRI-safety-labeled device, and package configuration data. For procurement and value-analysis staff, AccessGUDID is the authoritative place to confirm what a scanned or printed DI actually refers to before it’s entered into a purchasing, inventory, or EHR system.

Why UDI matters for lab and hospital procurement/supply chain

UDI was designed primarily as a patient-safety and adverse-event-tracing mechanism, but it has become infrastructure that procurement and supply-chain systems depend on:

  • Recalls and safety communications. A DI-level or lot/serial-level (PI) match against GUDID and FDA recall data lets a facility identify exactly which units on its shelves or already in use are affected, rather than pulling an entire product line on a brand-name match alone.
  • Purchasing and contract data integrity. Group purchasing organizations (GPOs), value analysis committees, and ERP/materials-management systems increasingly key device catalog data to the GS1/HIBC/ISBT device identifier rather than a vendor-specific item number, reducing duplicate or mismatched catalog entries across suppliers. See our guide on the value analysis committee approval process and on GPO purchasing arrangements for how device data feeds those workflows.
  • EHR and implant registries. Many EHR systems now capture the UDI (not just a free-text device description) in the patient record at the point of use for implants and other devices, supporting more precise post-market surveillance and registry reporting.
  • Inventory and expiration management. Because the PI can carry lot number and expiration date in machine-readable form, UDI scanning supports automated first-expired-first-out inventory rotation in a way that a brand-only barcode does not.

Compliance timeline: who has to comply, and by when

The FDA’s UDI rule, finalized in 2013, phased in compliance obligations by device risk class over several years rather than all at once, with the highest-risk devices required first:

  • Class III devices (highest risk, e.g. many implants) were the first required to bear a UDI on their label and have data submitted to GUDID.
  • Implantable, life-supporting, and life-sustaining devices across other classes followed on a subsequent compliance date.
  • Class II devices had a later compliance date.
  • Class I and unclassified devices were the last tier, with FDA granting additional exceptions and extensions for certain low-risk and legacy device types along the way.

Because FDA has granted device-specific exceptions, alternatives, and enforcement-discretion extensions since the original rule (particularly for Class I devices and certain combination products), the current compliance status for any specific device type should be confirmed against FDA’s own UDI guidance and GUDID rather than assumed from the general class-based schedule above — the original phase-in dates are a starting reference point, not a substitute for checking the device-specific current requirement.

UDI vs. other device/product identifiers

UDI is sometimes confused with other identifier systems procurement staff encounter:

  • NDC (National Drug Code) identifies drug products, not devices, and is FDA’s separate pharmaceutical identifier system — some combination products carry both.
  • HCPCS/CPT billing codes identify a procedure or service category for reimbursement purposes; they are not device-specific and do not distinguish between manufacturers, models, or lots the way a UDI does.
  • A manufacturer’s internal catalog/SKU number is vendor-specific and not standardized across suppliers, which is precisely the fragmentation problem UDI and GS1/HIBC/ISBT-based catalog data are meant to resolve for cross-vendor purchasing systems.
  • The EU UDI and Eudamed use a comparable DI/PI structure but rest on a separate legal basis and a separate database: EU device data is registered in the Eudamed UDI/Device module under Article 29 of Regulation (EU) 2017/745, not in GUDID, and that module became mandatory on 28 May 2026. A GUDID submission does nothing for EU compliance and vice versa — see our Eudamed module status and registration guide.

Frequently asked questions

What is UDI in a medical device?

UDI (Unique Device Identifier) is a two-part code — a fixed Device Identifier (DI) plus one or more variable Production Identifiers (PI, e.g. lot, serial, expiration date) — that the FDA requires most medical device labelers to assign, mark on device labels/packaging in machine-readable form, and submit DI-level data for to the GUDID database, under 21 CFR Part 830 and 21 CFR 801 Subpart B.

What are the UDI requirements for medical devices?

At a minimum: labelers must obtain a DI from an FDA-accredited issuing agency (GS1, HIBCC, or ICCBBA), mark the device label and, where applicable, the device itself with the UDI in both human-readable and automatic-identification (barcode/RFID) form, and submit the associated device record to GUDID. Exact obligations (labeling, direct device marking, GUDID submission) and their compliance dates vary by device risk class and by any device-specific exceptions FDA has granted, so they should be confirmed against current FDA UDI guidance for the specific device type in question.

Is a UDI the same as a barcode?

Not exactly. The UDI is the identifier (the DI+PI data); the barcode (or RFID tag) is one of the carrier mechanisms used to encode that identifier in machine-readable form on the label. The same UDI data could in principle also appear as plain text without a barcode, though FDA’s rule specifically requires an automatic identification and data capture (AIDC) technology — in practice almost always a barcode — alongside the human-readable form.

Where can I look up a device’s UDI record?

AccessGUDID, maintained by the National Library of Medicine, is FDA’s public interface to the GUDID database and the authoritative place to search DI-level device records by DI, brand name, or company name.

Related CASRAI resources

Further reading: FDA Approval for Gene Therapy — Gene therapy products are licensed via BLA (not approved via NDA), reviewed by CBER (not CDER), and often pursue RMAT designation.

Follow CASRAI

Research-administration guidance, standards updates and independent tool reviews.

Ask CASRAI · included with Regulatory Radar

Ask about UDI Medical Device: FDA Unique Device Identifier Requirements Explained

Ask CASRAI answers research-administration questions and cites the passages behind every claim — and says so when the corpus does not cover something, instead of guessing. It comes with a Regulatory Radar subscription at $29 a month, alongside the daily digest of regulatory changes and the dashboard of what changed.

150 questions a day, on this site, over the API, or inside your own tools through the CASRAI MCP server.

Everything CASRAI publishes — this page, the dictionary, the guides and the news — stays free to read, with no account and no card.

Referenced across the research world

University of Cambridge logoColumbia University logoCrossref logoUniversity of Edinburgh logoHarvard University logoUniversity of Oxford logoPrinceton University logoStanford School of Medicine logoUniversity College London logoORCID logoUniversity of Cambridge logoColumbia University logoCrossref logoUniversity of Edinburgh logoHarvard University logoUniversity of Oxford logoPrinceton University logoStanford School of Medicine logoUniversity College London logoORCID logo
  • University of Cambridge logo
  • Columbia University logo
  • Crossref logo
  • University of Edinburgh logo
  • Harvard University logo
  • University of Oxford logo
  • Princeton University logo
  • Stanford School of Medicine logo
  • University College London logo
  • ORCID logo

View CASRAI adoption →

Regulatory Radar

Stop finding out after the fact

$29/month, cancel anytime. Daily digest updates from our analysis, a dashboard holding the same items, and a cited assistant for everything they raise.

  • Federal Register, Federal Register+, Grants.gov, Regulations.gov, NSF News, UKRI, plus CASRAI’s own published content.
  • 72,264 indexed passages, and every answer cites the ones it drew on.