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National Drug Codes Explained

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Oct 1, 2020.

What is a National Drug Code (NDC)?

The NDC, or National Drug Code, is a unique 10-digit or 11-digit, 3-segment number, and a universal product identifier for human drugs in the United States.

The 3 segments of the NDC identify: the labeler, the product, and the commercial package size.

  • The first set of numbers in the NDC identifies the labeler, such as the drug manufacturer, repackager, or distributer. 
  • The second set of numbers is the product code, which identifies the specific strength, dosage form (i.e, capsule, tablet, liquid) and formulation of a drug for a specific labeler. 
  • Finally, the third set is the package code, which identifies package sizes and types.

The labeler code is assigned by the U.S. Food and Drug Administration (FDA), while the product and package code are assigned by the labeler. For billing or other purposes, such as with the Centers for Medicare & Medicaid Services (CMS), an NDC may also be arranged in an 11-digit format with leading zeros, if needed.

The NDC Directory is limited to all over-the-counter (OTC) medications, prescription medications, and insulin packages in the U.S. FDA publishes the listed 10-digit NDC numbers and the information submitted as part of the listing information in the NDC Directory which is updated regularly.

As of June 1, 2011, only drugs for which electronic listings (Structured Product Labeling or SPL) have been submitted to FDA are included in the NDC Directory. Animal drugs, blood products, or human drugs, among others, that are not in final marketed form are not included in the NDC directory.

How is the NDC formatted?

The 10-digit NDC will be in one of the following configurations: 4-4-2, 5-3-2, or 5-4-1, meaning that there are 4 or 5 digits for the labeler code, 4 or 3 digits for the product code and 2 or 1 digit(s) for the package code.

Example NDC

NDC - National Drug Code

For example, the NDC for a 100-count bottle of Prozac 20 mg is 0777-3105-02.

The first segment identifies the labeler (the labeler code "0777" is for Dista Products Co., the labeler of Prozac).

The second segment, the product code, identifies the strength, dosage form (i.e, capsule, tablet, liquid) and formulation of a drug for a specific labeler ("3105" identifies that this dosage form is a capsule).

The third segment is the package code, and it identifies package sizes and types. The package code "02" for this bottle of Prozac identifies that 100 capsules are in the bottle.

Where can I find an NDC number for a drug?

Why are some drug products not in the NDC Directory?

According to the FDA, reasons why a drug product may not appear in the NDC Directory, include:

  • the product may not be a prescription drug, OTC, or an insulin product.
  • the firm has notified the FDA that the product is no longer commercially available and marketed.
  • The manufacturer has not provided a complete listing of the drug product.

The FDA requires that drug establishment registration and drug listing information be submitted electronically unless a waiver is granted.

Why do some NDC numbers have 11 digits?

For certain purposes, including the proper billing of drug products, an 11-digit NDC may be required. The Centers for Medicare & Medicaid Services (CMS) and other government entities require an NDC as part of their billing claim form. Some government agencies, including HIPAA, may require the NDC in an 11-digit format with leading zeros. Increasingly, private payers are requiring the 11-digit code, but rules can vary greatly.

  • The CMS NDC identifier is formatted as 11 digits with no spaces, hyphens or other characters.
  • If the NDC Package code is less than 11 digits (for example, a 4-4-2 structure) the code must be padded with leading zeros.
  • The leading zero is added to the needed section to create a 5-4-2 configuration.

NDC numbers have also appeared with an asterisk in either a product code or a package code. The asterisk acts as a placeholder and indicates the configuration of the NDC.

Per the FDA, because of a conflict with the HIPAA standard of an 11-digit NDC, many programs will pad the product code or package code segments of the NDC with a leading zero instead of an asterisk. However, according to the FDA, asterisks are no longer used or included within the product file data elements to indicate certain configurations of the NDC.

Since a zero can be a valid digit in the NDC, this can lead to confusion when trying to return the 11-digit NDC back to its 10-digit FDA standard. For example, as noted by the FDA, 12345-0678-09 (11 digits) could be 12345-678-09 or 12345-0678-9 depending on the firm's configuration.

How do you convert a 10-digit NDC to an 11-digit NDC?

Increasingly, payers are requiring an 11-digit NDC code for billing purposes. Therefore, proper billing may require a specially-placed zero to create a 5-4-2 format depending upon the drug product’s 10-digit NDC. See Table 1 for conversion examples.

Note that hyphens for the 11-digit NDC (in the last column below) are for illustration purposes only, and should NOT be used when submitting data for a claim.

Table 1: 10-Digit to 11-Digit NDC Conversion

10-Digit Format on package 10-Digit Format on package Converted 11-Digit Format Actual 10-digit example 11-digit conversion example
Table 1: Adapted from Maryland Dept. of Health (
4-4-2 9999-9999-99 5-4-2 0777-3105-02 (Prozac) 00777-3105-02
5-3-2 99999-999-99 5-4-2 43063-609-30 (alprazolam) 43063-0609-30
5-4-1 99999-9999-9 5-4-2 11822-0544-1 (acetaminophen) 11822-0544-01

How are NDC numbers used for billing purposes?

When submitting a claim for reimbursement, it is always best to check with the payer(s) to determine the specifics for NDA coding and reimbursement, as rules vary widely. According to the American Academy of Pediatrics (AAP), many payers like Blue Cross and Blue Shield, Tricare, and state Medicaid plans have guidance on how they want NDC codes to be used. In addition, some Medicaid plans exclude the use of NDC codes for vaccines.

Will 10-digit NDC numbers run out?

Yes, the FDA states that the 5-digit format provides 90,000 potential combinations, and expects to run out of labeler codes by roughly 2033.

In 2018, the FDA conducted a public hearing to listen to healthcare industry stakeholders to determine the appropriate next steps for NDC code transition. The FDA published the proposed rule: “Future Format of the National Drug Code; Public Hearing; Request for Comments” in the Federal Register (Docket No. FDA-2018-N-2610). Public comments for the proposed rule were accepted until January 5, 2019.

As stated in the rule, FDA will begin assigning 6-digit labeler codes at some point in the future due to exhaustion of 5-digit labeler codes. Moving up to 6-digit labeler codes will expand NDCs to 11 digits and allows for two additional NDC configurations: 6-3-2 and 6-4-1, for a total of five possible NDC configurations (including the three 10-digit NDC configurations).


  1. Coding Corner: How to use National Drug Codes when billing for medications, vaccines. American Academy of Pediatrics (AAP). AAP News. Accessed Oct. 1, 2020 at
  2. National Drug Code (NDC) Directory. The U.S. Food and Drug Administration (FDA). Accessed Oct. 1, 2020 at
  3. National Drug Code Database Background Information. The U.S. Food and Drug Administration (FDA). Accessed Oct. 1, 2020 at
  4. NDC Product File Definitions. The U.S. Food and Drug Administration (FDA). Accessed Oct. 1, 2020 at
  5. Millonig M. Are You Prepared for a Major Industry Change to the National Drug Code (NDC) Number? Wolters Kluwer. Accessed Oct. 1, 2020 at

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.