The NDC is used to report prescribed drugs and biologics when required by government regulation, or as deemed by the provider to enhance claim reporting/adjudication process . The NDC for each service being billed should be entered in the shaded section of 24.
NDC should be entered in the shaded sections of item 24A through 24G. To enter NDC information, begin at 24A by entering the qualifier N4 and then the 11 digit NDC information. Do not enter a space between the qualifier and the 11 digit NDC number. Dont enter hypen or space within number/code.
The following qualifiers are used when reporting NDC units
F2 – International unit
GR – Gram
ML – Milliliter
U
N – Unit
Example of entering the identifier N4 and the NDC number on the CMS 1500 claim form
https://www.cms1500claimbilling.com/2010/10/reporting-ndc-on-cms-1500-claim-form.html