NDC 10 ↔ 11 Digit Converter
NDC 10 ↔ 11 Digit Converter - a deterministic tool in Sophie Well's Billing & Coding group.
Open the NDC 10 ↔ 11 Digit Converter → Runs in your browser. No signup, no tracking.
What this is
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). 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. The tile 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 tile.
References
CMS NDC billing guidance (5-4-2 billing format) and FDA Structured Product Labeling.
Worked example: Billing 11: 01234-5678-90 / FDA 10: 1234-5678-90.
Sophie Well is a reference and educational tool. Not medical, legal, or financial advice. Does not replace clinician judgment, professional billing review, or legal counsel.