NDC 10 ↔ 11 Digit Converter
Translate a National Drug Code between its FDA-assigned 10-digit segmentation (4-4-2, 5-3-2, or 5-4-1 depending on the labeler) and the CMS 11-digit billing form (5-4-2).
Open the tool → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- NDC in any hyphenated form, e.g. 1234-5678-90
- 1234-5678-90
Result: Billing 11: 01234-5678-90 / FDA 10: 1234-5678-90.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- NDC in any hyphenated form, e.g. 1234-5678-90
What this is
The conversion inserts a leading zero into the labeler, product, or package segment depending on which one is short; Sophie Well shows both formats side-by-side along with the leading-zero rule that applies to the input you provided. This tool also normalizes hyphenation and rejects malformed inputs.
When to use it
Use this whenever a billing claim, formulary system, 340B accumulator, or PBM remittance is rejecting an NDC because of length - the FDA prints the 10-digit form on the carton and the bottle, but every payer system in the United States expects the CMS 11-digit form on the claim. The conversion is purely mechanical (no ambiguity, no judgment), but the rule about which segment gets the inserted zero varies by labeler so a mental shortcut tends to break on the edge cases. For the broader "what drug is this" question, follow the NDC into the NDC -> RxNorm crosswalk tool.
How this is calculated
CMS NDC billing guidance (5-4-2 billing format) and FDA Structured Product Labeling.
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.
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