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Pharmaceutical serialization gives every individual saleable package of a prescription drug its own identity, rather than only identifying the batch it came from. In US law the identity is a product identifier: the National Drug Code plus a unique serial number of up to 20 characters, shown together with the lot number and expiration date in a machine-readable barcode and in human-readable form. Packaging, receiving and verification teams use it to trace and check a package.
This page is general regulatory information, not legal, compliance or medical advice. It describes the US statute (21 U.S.C. 360eee and 360eee-1); other jurisdictions run separate regimes that are not covered here.
Short answer
Serialization assigns a unique number to each package so that one pack can be told apart from every other pack of the same product and lot. Under the US Drug Supply Chain Security Act (DSCSA) that number is combined with the product’s NDC to form the “standardized numerical identifier,” which sits in a product identifier together with lot number and expiration date. Read the timeline and trading-partner duties in the DSCSA guide; this page explains what the code itself is.
What pharmaceutical serialization means
A lot number says which batch a package belongs to, and many packages share it. Serialization adds a second level: the statute defines the standardized numerical identifier as a set of numbers or characters used to uniquely identify each package or homogenous case. It is composed of the National Drug Code for the specific product, including the particular package configuration, combined with a unique alphanumeric serial number of up to 20 characters.
The statute defines a “package” as the smallest individual saleable unit of product for distribution by a manufacturer or repackager that is intended by the manufacturer for ultimate sale to the dispenser. That is the unit that receives a serial number.
Product serialization and the product identifier
“Product serialization” in everyday use usually means applying and recording these unit-level identifiers. The legal term is product identifier: a standardized graphic that includes, in both human-readable form and on a machine-readable data carrier conforming to standards developed by a widely recognized international standards development organization, the standardized numerical identifier, lot number and expiration date.
What a serialized pack carries
| Element | What it identifies | Source |
|---|---|---|
| National Drug Code (NDC) | The specific product, including its package configuration | 21 U.S.C. 360eee |
| Serial number | The individual package; unique alphanumeric, up to 20 characters | 21 U.S.C. 360eee |
| Lot number | The batch, shared by many packages | 21 U.S.C. 360eee |
| Expiration date | Expiry of the product | 21 U.S.C. 360eee |
| Data carrier on a package | A 2-dimensional data matrix barcode | FDA Q&A guidance (June 2021), citing sec. 582(a)(9) |
| Data carrier on a homogenous case | A linear or 2-dimensional data matrix barcode | FDA Q&A guidance (June 2021), citing sec. 582(a)(9) |
NDC, lot and expiry were already familiar on drug labels; the serial number is what makes a pack individually identifiable. FDA’s guidance also states that the DSCSA requirements do not change the linear barcode requirements under 21 CFR 201.25, so the data matrix is an addition to, not a replacement for, that rule.
How it is used in the supply chain
Track and trace for pharmaceuticals
Section 582(g)(1) of the FD&C Act set interoperable, electronic, package-level tracing requirements to take effect 10 years after November 27, 2013. Under it, transaction information is exchanged in a secure, interoperable, electronic manner and includes the product identifier at the package level for each package. Verification happens at the package level, including the standardized numerical identifier, and may use aggregation and inference as necessary. The systems must also promptly provide transaction information and statements to FDA or other officials when a recall or a suspect or illegitimate product investigation requires it. See the distributor-side view in DSCSA compliance requirements for distributors.
FDA describes the law as outlining steps to an interoperable, electronic way to identify and trace certain prescription drugs at the package level, with the aim of enabling rapid response to remove harmful drugs from the supply chain (FDA DSCSA page, content current as of 10/16/2025). Under section 582, a manufacturer or wholesale distributor that determines a product is illegitimate must notify FDA and its immediate trading partners within 24 hours of that determination.
Serialization versus lot-level control
Lot-level control can narrow a problem to a batch. Package-level identity lets a record refer to one pack. The statute’s “suspect product” definition covers a product that is potentially counterfeit, diverted or stolen, potentially intentionally adulterated in a way that would result in serious harm or death, potentially the subject of a fraudulent transaction, or that appears otherwise unfit for distribution in a way that would pose a similar risk. Quarantine is defined as storing or identifying a product to prevent distribution, in a physically separate area clearly identified for the purpose or through other procedures.
Where it matters for labs, clinics and supply decisions
For staff who receive prescription drugs, the sourced facts translate into a short checklist of what a serialized shipment should let you see. This is an interpretation of the statute and FDA guidance, not a compliance determination for any facility.
- The incoming transaction information should include the product identifier at the package level for each package.
- The package should carry NDC, serial number, lot and expiry in a data matrix barcode, with the same data readable by people.
- Package-level verification should be possible against the standardized numerical identifier.
- A package that fits the “suspect product” definition should be held apart (quarantine) pending investigation.
- A product determined to be illegitimate triggers notification to FDA within 24 hours of that determination.
Related reading: Good Distribution Practice for storage and transport, GS1-128 barcodes for logistics labelling, and healthcare distribution for the channel itself.
Common misunderstandings
- Serial number is not lot number. The lot identifies a batch; the serial number identifies one package.
- The serial number is not the whole identifier. It is combined with the NDC, and the product identifier adds lot and expiry.
- The data matrix does not replace the linear barcode rule. FDA states that 21 CFR 201.25 is unchanged.
- Guidance is not law. FDA’s Q&A guidance describes current agency thinking and does not create legally enforceable responsibilities.
FAQ
What is pharmaceutical serialization?
Giving each saleable package of a drug a unique serial number that, with the NDC, lot and expiration date, forms a machine-readable product identifier.
What is in a US serial number?
A unique alphanumeric string of up to 20 characters, combined with the product’s NDC to form the standardized numerical identifier.
Is track and trace the same as serialization?
No. Serialization creates the package-level identity; tracing uses that identity in electronic transaction information and verification across trading partners.
What barcode carries the identifier?
A 2-dimensional data matrix barcode on packages, and a linear or 2-dimensional data matrix barcode on homogenous cases.
Sources
- 21 U.S.C. 360eee (FD&C Act sec. 581), Cornell Legal Information Institute, https://www.law.cornell.edu/uscode/text/21/360eee, checked 2026-11-01.
- 21 U.S.C. 360eee-1 (FD&C Act sec. 582), https://www.law.cornell.edu/uscode/text/21/360eee-1, checked 2026-11-01.
- FDA, Product Identifiers Under the Drug Supply Chain Security Act: Questions and Answers, June 2021, https://www.fda.gov/media/116304/download, checked 2026-11-01.
- FDA, Enhanced Drug Distribution Security at the Package Level Under the DSCSA, Guidance for Industry, January 2024 (Procedural Revision 1), https://www.fda.gov/media/171666/download, checked 2026-11-01.
- FDA, Drug Supply Chain Security Act (DSCSA), https://www.fda.gov/drugs/drug-supply-chain-integrity/drug-supply-chain-security-act-dscsa, checked 2026-11-01.
