Device Identification
Device Identification is the regulatory system used to uniquely and consistently identify medical devices through a Unique Device Identification (UDI) code and associated data. A UDI consists of a Device Identifier (DI)—the fixed, model-specific code—and one or more Production Identifiers (PI)—dynamic data such as lot, serial number, manufacturing or expiration date. The UDI appears on labels/packaging as machine-readable Automatic Identification and Data Capture (AIDC) plus Human-Readable Interpretation (HRI), and for certain reusable devices it must also be directly marked on the device.
UDI (DI + PI)AIDC + HRITraceability
Frameworks & core concepts
- United States (FDA): UDI requirements are in 21 CFR 801 Subpart B and 21 CFR 830. Labels must bear a UDI; certain reusable, reprocessed devices must also be directly marked with the UDI (21 CFR 801.45). Device labelers must submit device records to the GUDID database (DI-keyed; PIs are not stored). FDA permits exceptions or alternatives under 21 CFR 801.55 in specific cases. Recognized issuing agencies include GS1, HIBCC, and ICCBBA.
- European Union (MDR/IVDR): UDI is mandated by Reg. (EU) 2017/745 and 2017/746. In addition to UDI-DI/PI on labels, the EU uses a parent Basic UDI-DI to group related devices for certifications and EUDAMED registration (see MDCG 2018-1 Rev.4). Manufacturers register UDI/device data in EUDAMED (module available; mandatory timeline phased with overall EUDAMED deployment). Symbols/label content follow MDR Annex I Ch.III and harmonized standards (e.g., ISO 15223-1).
Key dates & direct marking (EU)
- UDI carrier on labels (MDR): Class III & implantable: 26 May 2021 · Class IIa/IIb: 26 May 2023 · Class I: 26 May 2025.
- Direct marking on reusable devices (MDR): Class III & implantable: 26 May 2023 · Class IIa/IIb: 26 May 2025 · Class I: 26 May 2027.
- IVDR label deadlines: Class D: 26 May 2023 · Class B/C: 26 May 2025 · Class A: 26 May 2027.
Note: EUDAMED device/UDI registration is live on a voluntary basis; mandatory use is linked to the Commission’s EUDAMED deployment schedule.
What to include on your identification set
- UDI on label/pack: AIDC (e.g., barcode, 2D DataMatrix) + HRI (plain text).
- PI elements (as applicable): lot or serial number, manufacturing date, expiration date, software version/build.
- Direct mark (if required): Durable UDI on device itself for reusable, reprocessed devices (EU and U.S. rules apply).
- Database submission: GUDID (U.S.: DI-keyed) and EUDAMED (EU: device/UDI + EMDN code; includes Basic UDI-DI linkages).
Common pitfalls
- Mismatching AIDC and HRI strings or omitting PI where your process produces it.
- Using the Basic UDI-DI on the label (it must not appear on the commercial label).
- Missing direct mark on reusable/reprocessed devices or applying it to the wrong part of the device.
- Out-of-sync records between labels, GUDID/EUDAMED, technical documentation, and certificates.
Device Identification — FAQs
What is the difference between DI and PI?
DI is the fixed identifier for the model/version family (U.S.) or the specific UDI-DI (EU). PI carries changing data like lot, serial, dates, or software version.
When is direct marking required?
U.S.: devices intended to be used more than once and to be reprocessed before each use must bear a permanent UDI (21 CFR 801.45). EU: reusable devices have class-based deadlines for direct marking under MDR Article 27 and Annex VI.
Does GUDID store PI data?
No. GUDID is keyed to the DI and contains identifying attributes; PI appears on the physical label/pack or direct mark, not in GUDID.
What is a Basic UDI-DI?
EU grouping key that ties a family of devices to certificates and EUDAMED entries; it does not go on the label. See MDCG 2018-1 Rev.4.
Are there exceptions?
Yes. FDA may grant exceptions/alternatives to UDI labeling (21 CFR 801.55), and both jurisdictions have specific carve-outs (e.g., certain investigational/custom-made contexts).
UDI — at a glance (U.S. vs EU)
| Topic | U.S. (FDA) | EU (MDR/IVDR) |
|---|---|---|
| Core concept | UDI = DI (fixed) + PI (variable) | UDI = UDI-DI (fixed) + UDI-PI (variable) + Basic UDI-DI (grouping key) |
| Label carrier | AIDC (e.g., GS1/HI BCC/ICCBBA) + HRI on label/pack; certain reusables need direct mark | AIDC + HRI on label/pack; Basic UDI-DI does not appear on the label |
| Database | GUDID submission (DI-keyed; PI not stored) | EUDAMED device/UDI registration (incl. Basic UDI-DI linkages; phased mandatory timeline) |
| Direct marking trigger | Devices intended for reuse and reprocessed between uses require permanent UDI on device (21 CFR 801.45) | Reusable devices require direct mark by class-based deadlines (MDR Art.27, Annex VI) |
| Deadlines snapshot | Fully phased; all classes now under UDI; new entries ongoing | Labels: Class III/implants 2021; IIa/IIb 2023; I 2025. Direct mark: III/implants 2023; IIa/IIb 2025; I 2027. IVDR labels: D 2023; B/C 2025; A 2027 |
| Exceptions | FDA may grant exceptions/alternatives (21 CFR 801.55); certain investigational/custom contexts differ | Specific carve-outs (e.g., investigational/custom-made); Basic UDI-DI rules via MDCG 2018-1 Rev.4 |
| Common pitfalls | AIDC ≠ HRI mismatch; missing direct mark; DI data errors in GUDID | Placing Basic UDI-DI on label; unsynced EUDAMED vs tech file; missed class deadlines |
- Tip: Build a single UDI master record that feeds labels, ERP/MES, and GUDID/EUDAMED to avoid mismatches.
- Reminder: Never print the Basic UDI-DI on commercial labels; keep it in certificates and EUDAMED records.