United States
Hong KongNDC numbers
An FDA-assigned National Drug Code identifies the labeler, product, and package in three segments.
- As of 2026, FDA-assigned NDCs remain 10 digits in three possible formats; many HIPAA-covered billing transactions use an 11-digit 5-4-2 version.
- FDA's uniform 12-digit format takes effect in 2033.
On this page7 sections
A small, precise topic that appears reliably because it is unambiguous and easy to test.
The three segments
| Segment | Identifies |
|---|---|
| First | The labeler - the firm that manufactures, repacks or distributes under its own name |
| Second | The product - the specific strength, dosage form and formulation |
| Third | The package - the size and type of packaging |
The structure is set out at 21 CFR 207.33.
Current FDA NDC formats
As of 2026, the FDA-assigned NDC is a unique 10-digit, three-segment code. The segments can be arranged as 4-4-2, 5-3-2, or 5-4-1: labeler, product, then package. The first segment identifies the labeler; the second identifies that labeler's specific drug product, including its strength, dosage form, and formulation; the final segment identifies the package size and type. The hyphens make the segment boundaries visible.
Do not assume that two packages of the same active ingredient share an NDC. A different manufacturer or labeler, strength, dosage form, formulation, or package configuration can have a different code. Use the complete product and package information when matching inventory, prescriptions, claims, and recall notices.
Why an NDC may appear as 11 digits
Many HIPAA-covered transactions use an 11-digit, 5-4-2 standard. A 10-digit FDA NDC is converted by adding a leading zero to the short segment, not by adding a zero to the beginning of the whole string in every case. For example, a 5-4-1 code receives a zero in the package segment; a 5-3-2 code receives it in the product segment; and a 4-4-2 code receives it in the labeler segment. The hyphenated FDA code shows which segment needs padding.
An 11-digit billing number can look different from the 10-digit NDC on a package. Use the original segment pattern or a trusted system conversion. A misplaced zero can identify a different product or package.
FDA's planned 12-digit format
FDA issued a final rule adopting a uniform 12-digit format with a 6-digit labeler code, 4-digit product code, and 2-digit package code. The rule takes effect on March 7, 2033. FDA will continue assigning current-format 10-digit NDCs during the transition period before that date, and the 11-digit HIPAA billing format is not changed by the FDA rule. Do not describe the new native FDA format as already in force in 2026.
Two NDCs sharing a labeler segment and differing in the product segment are different strengths or forms from the same firm. That is exactly the pair most likely to be confused on a shelf, which is why NDC checking is an error-prevention control and not just an inventory convenience.
What it is used for
- Identifying exactly which product was dispensed
- Billing and claims processing
- Recall handling, alongside the lot number
- Inventory and ordering
NDC against lot number
The NDC identifies what the product is. The lot number identifies which manufacturing run it came from.
A recall usually names both: the product by NDC and the affected batches by lot. Confusing the two is a standard distractor.
Where it connects to serialization
The Drug Supply Chain Security Act builds product tracing on top of product and package identification. The NDC is part of what makes a unit identifiable through the supply chain. Three segments, three jobs.
Since serialization is a named knowledge area on the current outline, the connection is worth holding rather than treating NDC as a standalone fact. Different things entirely.
Common questions
What are the three parts of an NDC?
Labeler, product and package, under 21 CFR 207.33.
Why do some NDCs have 11 digits?
Many HIPAA-covered billing transactions use an 11-digit 5-4-2 standard. A 10-digit FDA NDC is padded with a leading zero in the segment that is shorter, so the original hyphenated format matters.
When does FDA's 12-digit NDC format take effect?
The FDA rule takes effect on March 7, 2033. As of 2026, FDA continues to assign 10-digit NDCs in the current segment formats.
What does the product segment identify?
The specific strength, dosage form and formulation.
What is the difference between an NDC and a lot number?
The NDC says what the product is; the lot number says which manufacturing run it came from.
Why does NDC checking prevent errors?
Products differing only in the product segment are the ones most easily confused on a shelf.
How does it relate to serialization?
The DSCSA builds product tracing on product and package identification, of which the NDC is part.