The same drug package can carry a 10-digit NDC on its label, an 11-digit NDC on a claim, and starting March 7, 2033, a 12-digit NDC. Here's how each format works, how to convert between them, and where conversions go wrong.
· 6 min read
Written and clinically reviewed by Jacob Fuchs, PharmD
Reviewed on
A National Drug Code (NDC) is the FDA's 10-digit, three-part identifier for a drug product and its package. The same package can be written three ways: 10 digits with hyphens on the label, 11 digits with no hyphens on an insurance claim, and, under an FDA rule finalized in March 2026, 12 digits starting March 7, 2033. All three point to the same box. The trouble starts when someone converts between them by hand.
This guide explains each format, shows how to convert between them, and lists the places conversions go wrong in purchasing and billing.
Every listed drug product gets a unique 10-digit, three-segment number (openFDA):
That third segment matters more than it looks. Two NDCs that differ only in the last two digits are the same drug in a different package, such as a single vial versus a carton of 25. Reorder by the full NDC, not the first two segments, or you can end up with the right drug in the wrong count.
Because labeler codes come in different lengths. A 10-digit NDC is always one of three configurations: 4-4-2, 5-3-2, or 5-4-1 (openFDA). A firm with a 4-digit labeler code gets 4 digits for the product code; a firm with a 5-digit labeler code splits the remaining 5 digits between product and package.
The hyphens are what tell you which configuration you're looking at. Strip them out and 1234567890 could be any of the three.
The 11-digit format comes from the HIPAA standard for electronic health care transactions. It fixes every NDC at 5-4-2: a 5-digit labeler code, a 4-digit product code, and a 2-digit package code. To convert a 10-digit NDC, you add one leading zero to whichever segment is short (Federal Register, 91 FR 10749).
Using made-up digits:
| 10-digit configuration | Example | 11-digit (5-4-2) | Where the zero goes |
|---|---|---|---|
| 4-4-2 | 1234-5678-90 | 01234-5678-90 | Front of the labeler code |
| 5-3-2 | 12345-678-90 | 12345-0678-90 | Front of the product code |
| 5-4-1 | 12345-6789-0 | 12345-6789-00 | Front of the package code |
Where you'll see the 11-digit format: claims for drugs given in a clinic or office. Under the Deficit Reduction Act of 2005, states must collect NDCs for physician-administered drugs so they can bill manufacturers for Medicaid rebates (Medicaid.gov). Alabama Medicaid, for example, requires the 11-digit NDC in 5-4-2 format with no hyphens or spaces, and denies claims that lack a proper NDC for drugs on its required list (Alabama Medicaid). Check your own payers' rules; they vary.
Most errors come from four habits:
1. Dropping the hyphens before converting. Without hyphens, you can't tell which segment needs the zero. Convert first, or keep the original hyphenated NDC alongside the 11-digit version. 2. Letting a spreadsheet eat the leading zero. Spreadsheets treat an NDC as a number unless the column is formatted as text, and 01234567890 quietly becomes 1234567890. The FDA's position in the 2026 rule is blunt: leading zeros should not be truncated (91 FR 10749). 3. Matching on the product, not the package. A reorder keyed to the first two segments can bring in a different package size than the one on your shelf. 4. Assuming a substitute has the same NDC. It doesn't. A different labeler or product means a different NDC, so your billing records, inventory system, and any order sets keyed to NDC need the new one.
The FDA published a final rule on March 5, 2026, that adopts a single 12-digit NDC format (FDA). The new configuration is 6-4-2: a 6-digit labeler code, a 4-digit product code, and a 2-digit package code (FDA regulatory impact analysis).
Why: the FDA expects to run out of 5-digit labeler codes in about 10 to 15 years. The 6-digit labeler code adds roughly 900,000 more (91 FR 10749).
The dates (FDA):
How existing NDCs convert: by adding leading zeros to the labeler, product, and/or package segments as needed to reach 6-4-2 (FDA). Applied to the same made-up examples, 1234-5678-90 would become 001234-5678-90, 12345-678-90 would become 012345-0678-90, and 12345-6789-0 would become 012345-6789-00. The FDA says it will publish a database mapping each 10-digit NDC to its 12-digit equivalent, so use that crosswalk rather than converting by hand (91 FR 10749).
What the rule doesn't change: the HIPAA 11-digit format. The FDA states the rule does not alter NDC formats used for non-FDA purposes, such as the HIPAA 11-digit format used for reimbursement (FDA). Changing that standard is up to HHS.
Barcodes: the GTIN inside today's common linear drug barcodes cannot hold an NDC longer than 10 digits (FDA regulatory impact analysis). The rule allows linear or 2D barcodes that meet a recognized standard, and starting March 7, 2033, a single 2D Data Matrix barcode can carry both the NDC and the DSCSA product identifier (FDA).
Premier Pharma supplies licensed clinics, surgery centers, physician offices, and pharmacies, and every product page lists its NDC. Search by NDC, product name, or manufacturer in the NDC lookup, or open a free account — credential review typically takes 1–2 business days. For a worked example of ordering by NDC, see our anesthesia supplies purchasing guide.
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