The NDC System was originally established as an essential part of an out-of-hospital drug reimbursement program under Medicare. The NDC serves as a universal product identifier for human drugs. The current edition of the National Drug Code Directory is limited to prescription drugs and a few selected OTC products.
1. Product Trade Name or Catalog Name

The product names used in the Directory are generally those supplied by the labelers (firms) as required under the Food, Drug, and Cosmetic Act. All product names appearing in this Directory have been limited to a maximum of 100 characters. Minor editorial changes were made in some instances where information normally included with the name appears elsewhere in the product description. For example, where strength is ordinarily listed as a component of the product name, but also appears in other data fields, the strength may have been removed from the product name. The designations, United States Pharmacopeia (USP) or National Formulary (NF) may also have been deleted from product names. Occasionally, however, the term not NF and not USP have been left as part of the name. Symbols indicating trademarked or registered products also had to be omitted because of computer input capabilities. These deletions are not intended in any way to deprive the labeler of the protection afforded to him under patent, trademark, registration, or copyright laws or regulations.

2. National Drug Code (NDC)

Each drug product listed under Section 510 of the Federal Food, Drug, and Cosmetic Act is assigned a unique 10-digit, 3-segment number. This number, known as the National Drug Code (NDC), identifies the labeler/vendor, product, and trade package size. The first segment, the labeler code, is assigned by the FDA. A labeler is any firm that manufactures, repacks or distributes a drug product. The second segment, the product code, identifies a specific strength, dosage form, and formulation for a particular firm. The third segment, the package code identifies package sizes. Both the product and package codes are assigned by the firm. The NDC will be in one of the following configurations: 4-4-2, 5-3-2, or 5-4-1.

3. Dosage Form

The dosage form abbreviations are listed in TBLDOSAG.TXT.

4. Routes of Administration

The routes of administration abbreviations are listed in TBLROUTE.TXT.