Federal Contracting Acronym
NIIN
National Item Identification Number
Plain-English definition
The National Item Identification Number is the nine-digit item identifier within a National Stock Number. In federal practice, National Item Identification Number connects to how contracting officers, program offices, and industry teams interpret requirements, document decisions, and execute awards. Authoritative context is typically found in DLA materials and agency supplements where applicable. Contractors should trace how NIIN appears in the specific solicitation or contract rather than assuming uniform usage across agencies.
Why it matters
Understanding National Item Identification Number (NIIN) reduces misalignment during proposal preparation, contract performance, and compliance reviews tied to systems & registrations obligations.
Where you will see it
SAM.gov notices, contract clauses and attachments, DoD forms and supply systems when applicable, and internal capture or program management documentation.
Example in context
During a bid review, the capture lead notes NIIN in the solicitation, assigns a subject-matter owner to confirm requirements, and records the decision in the compliance matrix.