Your 11-digit NDC
This tool converts the format only. It does not look up the drug or verify that a claim will be accepted. Check the package and your payer’s current requirements before using the result. Enter only the NDC, without patient information.
Where does the zero go?
A 10-digit NDC has three sections separated by hyphens. Add a zero to the beginning of the shorter section to make 5 labeler digits, 4 product digits and 2 package digits. CDC explains the conversion; the NC Medicaid Managed Care guide, September 2026, page 25 shows these three conversions for billing under that program.
4-4-2 Add a zero to the labeler code
9999-9999-99becomes09999-9999-99
5-3-2 Add a zero to the product code
99999-999-99becomes99999-0999-99
5-4-1 Add a zero to the package code
99999-9999-9becomes99999-9999-09
The added zero is highlighted in each example. The converter also gives you the 11-digit NDC without hyphens to copy. Check your payer’s current instructions for the required format.
Why do I need the original hyphens?
Without hyphens, the converter cannot tell which of the three sections needs the zero. Check the original package NDC and enter it with the hyphens as shown. The converter will ask you to do this rather than guess.
A product NDC with only two sections is missing the package code. NLM distinguishes a product’s first two segments from its package NDCs. For vaccines, CDC also distinguishes primary and secondary packaging. Adding a zero does not identify which package to bill.
What about 12-digit NDCs?
FDA’s final rule takes effect March 7, 2033 and sets a 6-4-2 format for FDA-assigned NDCs. FDA states that this rule does not change the separate HIPAA 11-digit reimbursement format. It provides a label transition through March 6, 2036. Read the FDA format timeline.
This converter does not convert 12-digit NDCs or create the future FDA format. If you have a 12-digit number, check what it represents and which format your system requires. Do not remove a digit to make it fit.
Formatting does not verify the product
Even an NDC Directory entry does not establish FDA approval or payer coverage, and the directory does not contain every listed drug. FDA explains these limits. Converting the format does not confirm that an NDC is listed, FDA-approved or covered by a payer.
If a claim is rejected, check the reject-code reference and your payer’s current payer sheet or manual. Changing the NDC format may not resolve the rejection.
Sources5 linked sources
- CDC, NDC Crosswalk tables: normalization and vaccine packaging; last reviewed September 5, 2024.
- NC Medicaid Managed Care Billing Guidance, v36.02: September 4, 2026, section 3.19.1, page 25. Applies to the named managed-care context; not a national or FFS billing rule.
- NLM, RxNorm findRelatedNDCs documentation: product versus packaging; undated, checked October 13, 2026.
- FDA, National Drug Code Format: final rule published March 5, 2026, effective March 7, 2033; checked October 13, 2026.
- FDA, National Drug Code Directory: listing and coverage limits; checked October 13, 2026.