# National Information Exchange Model
**Entity class:** Information-exchange standard and governance framework
**Domain:** Semantic interoperability / public safety / government data
**Doc Type:** Standards Node
**Maturity:** Developed
## Definition
The **National Information Exchange Model (NIEM)** supplies a common vocabulary, data components, and exchange-development framework for information shared across otherwise incompatible government and partner systems.
## ICEPIC and LEIS Role
The historical DHS LEIS briefing described standards-based messages using NIEM-related models and [[wiki/Law Enforcement Exchange Specification|LEXS]] exchange specifications. The standardization layer allowed a regional system to formulate a person query and interpret a response without adopting the internal schema of TECS, ENFORCE, or ICEPIC.
NIEM enables [[wiki/Semantic Interoperability|semantic interoperability]], but it does not create legal authority to share. A successful exchange requires at least four distinct elements: an agreement or authority, authenticated users, a technically valid message, and permitted data use. Shared field names do not resolve source accuracy, identity ambiguity, retention, or downstream action.
## Sources / Provenance
- [[research/Immigration and Customs Enforcement Pattern Analysis and Information Collection (ICEPIC)|ICEPIC research dossier]]
- [DHS — LEIS briefing, slides 4–8](https://info.publicintelligence.net/DHS-LEISS.pdf)
- [NIEM — official program site](https://www.niem.gov/)
## Relationships
- **implements:** [[wiki/Semantic Interoperability|Semantic Interoperability]].
- **exchange family:** [[wiki/Law Enforcement Exchange Specification|Law Enforcement Exchange Specification]].
- **historical interface:** [[wiki/DHS Law Enforcement Information Sharing Service|DHS LEIS Service]].
- **message transformation:** [[wiki/IBM DataPower|IBM DataPower]].