Knowledge base

NDC Coding & Billing Guide

Worked explanations of the things that actually go wrong on a drug claim — code formats, the 11-digit conversion, product versus package codes, and what the FDA marketing categories mean.

6 explainers153 glossary terms30 J-codes
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If a claim was rejected for an invalid NDC, the cause is almost always one of two things: a two-segment product NDC where a package code was required, or a 10-digit code that was never padded to 11.

The explainers

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NDC fundamentalsWhat is a National Drug Code (NDC)?A National Drug Code is the FDA's universal product identifier for a human drug — a three-segment number that names the company responsible for the label, the specific formulation, and the package size it was sold in.Read NDC anatomyHow do I decode the three segments of an NDC number?Read an NDC left to right as labeler, product, package: the first segment (4-5 digits) is the company, the second (3-4 digits) is the formulation and strength, and the third (1-2 digits) is the package size.Read 11-digit HIPAA conversionHow do I convert a 10-digit NDC to the 11-digit billing format?Insert a single leading zero into whichever segment is one digit short: 4-4-2 pads the first segment, 5-3-2 pads the second, 5-4-1 pads the third — always producing a 5-4-2 code, and never simply adding a zero to the front of the whole number.Read Product vs packageWhat is the difference between a Product NDC and a Package NDC?A product NDC has two segments and identifies a formulation regardless of packaging; a package NDC has three segments and identifies an exact box — and only the package NDC is billable.Read FDA categoriesWhat do NDA, ANDA and BLA marketing categories mean?The marketing category states the legal basis on which a drug is sold: NDA for a brand-name drug approved on its own evidence, ANDA for a generic proved bioequivalent to that brand, and BLA for a licensed biological product.Read Data sourcesWhere does MedCode Info get its NDC and drug data?Drug records come from the FDA's openFDA Drug NDC Directory and Structured Product Labeling submissions, trial records come from the ClinicalTrials.gov API, and the HCPCS crosswalk is maintained here against the quarterly CMS code file.Read

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Glossary

153 definitions covering NDC, HCPCS, claims, reimbursement, FDA regulation and clinical trials — one term per page.

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J-code directory

30 HCPCS codes with descriptors, billable units and dose-to-unit conversions.

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NDC lookup

Search the FDA registry by code, brand, generic or labeler, with the 11-digit conversion already applied.

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