FDA UDI Labeling Requirements for Medical Devices
Short Answer
FDA UDI labeling requires most medical device labels to carry a unique device identifier in both plain text and machine-readable form, built from a fixed device identifier plus a variable production identifier. Labelers submit device identifier records to GUDID, and reusable reprocessed devices generally need direct marking as well.
What the UDI Rule Asks a Labeler to Do
The FDA unique device identification system has two halves. Most devices must carry a unique device identifier on the label and package in both plain text and machine-readable form, and the labeler must submit a record for that device to the Global Unique Device Identification Database. Some devices must also be marked on the device itself. The obligations sit with the labeler, which is normally the manufacturer but can be a specification developer, repackager or relabeler.
The requirements live in the labeling regulations at 21 CFR Part 801 subpart B and the database requirements at 21 CFR Part 830. Read the current text of those parts, and current FDA guidance, before you make a determination for a specific product. This page explains the printing and marking consequences of the rule, which is the part we can actually help with.
Inside a UDI: Device Identifier and Production Identifier
A UDI is not one number. It is a fixed portion plus a variable portion, and the difference matters enormously for how you print it.
- Device identifier, or DI. Mandatory and fixed. It identifies the labeler and the specific version or model of the device. One DI per version or model, and it never changes on the fly. It is the key that links a physical package to the database record.
- Production identifier, or PI. Conditional and variable. Depending on what appears on the label, the PI conveys lot or batch number, serial number, expiration date, date of manufacture, and for certain human cell and tissue products a distinct identification code.
Because the PI changes from run to run and often from unit to unit, a UDI carrier is variable data by nature. Preprinted stock alone cannot satisfy it for serialized or lot-controlled product. That single fact usually decides the printing architecture: thermal transfer printing at the point of packaging, driven by the system that owns the lot and serial data.
Issuing Agencies and Carrier Formats
UDIs are issued under systems operated by FDA-accredited issuing agencies rather than by FDA itself. Each agency publishes its own data structure and encoding rules, and your choice determines what the barcode actually looks like and what application identifiers or data qualifiers appear inside it. Confirm the current accredited list with FDA before you commit, because accreditation status is administrative and can change.
The carrier itself is usually a GS1-128 linear symbol, a GS1 DataMatrix, or a two-dimensional symbol under another agency system. Whichever you choose, the label must also present the UDI in plain text that a person can read without a scanner, and the encoded data must agree exactly with that text.
Submitting Device Data to GUDID
GUDID holds device identifier records, not production data. You submit the DI along with descriptive attributes for the device version or model, and you never submit lot numbers, serial numbers or expiration dates. Records are created through the FDA web interface or by structured HL7 SPL submissions, and the public face of the database is AccessGUDID.
The practical trap is drift. A label change that alters the version or model, or the package configuration, may need a new DI and a new database record. Build a checkpoint into your change control so that a packaging engineering change cannot reach production without someone confirming whether the DI and its GUDID record still describe reality.
Label, Package, or Direct Part Marking
Most devices satisfy the rule with a printed label on each package level that is intended to reach a user. Devices intended to be reused and reprocessed between patients generally have to carry the UDI on the device itself, so that identity survives after the packaging is discarded. The regulation sets out the conditions and the exceptions, so check the current text rather than a summary.
| Marking approach | Where it fits | What to watch |
|---|---|---|
| Thermal transfer label | Most packaged devices, sterile barrier and shelf cartons | Ribbon and facestock must be matched to the sterilization method and shelf life |
| Direct thermal label | Short-life secondary packaging and internal logistics only | Image fades with heat, light and solvents. Rarely appropriate for a UDI carrier |
| Preprinted stock with variable overprint | High volume lines with fixed artwork and changing lot or serial data | Registration, and verifying that the overprinted PI matches the preprinted DI |
| Laser marking on the device | Reusable stainless instruments and metal handpieces | Surface change and passivation, plus contrast after repeated reprocessing |
| Dot peen marking | Robust metal instruments where depth aids survival | Stress risers, cleanability of the marked recesses |
| Chemical etch | Delicate or thin-wall instruments | Process validation and corrosion control |
Durability and Legibility Expectations
A UDI that cannot be read is not doing its job, and the rule expects the identifier to remain legible through the conditions the device will actually see. For a printed label that means the whole system has to be qualified together: facestock, adhesive, ribbon chemistry, printer settings and the sterilization or storage exposure that follows.
- Sterilization exposure. Steam, ethylene oxide, gamma and electron beam each stress a label differently. Resin or near-resin ribbons on synthetic facestock survive far better than wax on paper.
- Adhesive behavior. Low surface energy plastics, curved handpieces, cold storage and humidity all pull labels off. Qualify the adhesive on the actual substrate, not on a flat test panel.
- Abrasion and handling. Cartons rub in transit and instrument trays rattle. Test the printed image after handling, not only fresh off the printer.
- Symbol quality. Grade linear symbols to ISO/IEC 15416 and two-dimensional symbols to ISO/IEC 15415. Marks made directly on a device are graded under the direct part marking methodology in ISO/IEC 29158, which is a different measurement and usually a different verifier setup.
- Small carriers. Tiny devices force small X-dimensions, which raises the bar for printhead resolution, media smoothness and verification. This is where most legibility problems start.
Our explainer on barcode print quality grading and verification covers what those grades actually measure and how a verifier differs from a scanner.
Class-Based Applicability and Phase-In
UDI obligations were never switched on all at once. FDA phased compliance in by device class, beginning with the highest-risk devices and working down, with separate later dates for direct marking and for some low-risk categories. Exceptions, alternatives and periods of enforcement discretion have applied along the way, and some device types are excepted entirely.
That history matters mainly for one reason: you cannot infer your obligation from what a competitor does or from an article written a few years ago. Determine class and applicability from the current regulation text and current FDA guidance for your specific device, and document how you reached the conclusion. If a determination is not obvious, that is a question for your regulatory affairs function or regulatory counsel.
What to Confirm Before You Print
Once the regulatory determination is made, the printing side is a checklist:
- Data ownership. Which system issues lot, serial and expiration values, and how they reach the label template without manual retyping.
- Template control. A versioned template per device family, with the plain-text UDI and the encoded data generated from the same field so they cannot diverge.
- Print and verify. Verification at or immediately after the printer, with a fail routing that quarantines the package rather than trusting an operator to notice.
- Media control. Locked-down facestock and ribbon part numbers, with a change-control gate. A substituted roll can invalidate a durability qualification.
- Records. Grade reports and print logs retained with the batch record, which is what makes an audit conversation short.
Where PCI Fits, and Where We Do Not
To be plain about it: PCI advises on the printing and marking side. We do not determine device class, decide whether your product is in scope, or prepare your GUDID submissions. Your regulatory affairs team and the current regulation own those questions.
What we do is make the identifier print correctly and survive. We specify and support industrial barcode and thermal label printers for high-resolution small-symbol work, match label media and ribbon combinations to your sterilization and storage profile, and install label output validators so every carrier is graded as it is produced. Our industrial label printing consulting group will sit with your packaging and quality engineers to qualify the combination and document it. Send us your label drawing and sterilization method, or request a quote.
Need a UDI Carrier That Survives Sterilization?
Send us your label drawing, symbol size and sterilization method. PCI will recommend a printer, facestock and ribbon combination, then help you qualify and verify it so every carrier grades the way your quality system expects.
Frequently Asked Questions
Is a UDI the same thing as a GTIN?
No, though they are related. A GTIN is a GS1 product number that can serve as the device identifier portion of a UDI when it is issued under the GS1 system. The full UDI also includes the production identifier data such as lot, serial or expiration when those appear on the label, along with the data qualifiers that tell a scanner what each field means. Treat the GTIN as one component, not as the whole identifier.
Does every package level need its own UDI?
Generally each package configuration intended to reach a user needs an identifier, and each distinct configuration gets its own device identifier and its own database record. Shipping containers that exist only for transport are typically handled differently. The specifics depend on how your packaging hierarchy is defined and on the current regulation text, so map your levels first and confirm each one with your regulatory affairs team before designing the labels.
Do we submit lot and serial numbers to GUDID?
No. GUDID holds device identifier records and descriptive attributes for a version or model. Production data such as lot number, serial number, expiration date and manufacturing date stays on the label and in your own traceability systems. This is why the database record can be created once and maintained through change control, while the production identifier portion of the printed carrier changes with every batch or unit.
Which devices have to be marked on the device itself?
Direct marking generally applies to devices intended to be used more than once and reprocessed between uses, so that identity survives after packaging is discarded. Reusable surgical instruments are the common example. The regulation also sets out exceptions, including cases where marking would interfere with safety or effectiveness or is not technologically feasible. Confirm applicability for your specific device from the current regulation rather than by analogy.
Will steam or gamma sterilization ruin a printed UDI label?
It can, if the label was not chosen for it. Wax ribbons on paper facestock smear or fade under steam and solvents, and some adhesives creep or discolor after gamma or ethylene oxide exposure. A resin or near-resin ribbon on a synthetic facestock, matched to the printer and to the specific cycle, holds up far better. Always qualify the exact facestock, adhesive, ribbon and printer combination through your real sterilization cycle.
What barcode grade should a UDI carrier achieve?
Set the internal threshold from your customers, your scanning environment and your quality system rather than from a single universal figure. In practice manufacturers commonly target a comfortable margin above the minimum any downstream reader needs, because grades drift as printheads wear. Grade printed labels under ISO/IEC 15416 or 15415 depending on symbology, and use the direct part marking method in ISO/IEC 29158 for marks made on the device surface.