What is the IEPD file format?
An .iepd file is an Information Exchange Package Documentation package. It bundles everything needed to define a standardized data exchange: XML schemas, sample messages, a catalog and human-readable documentation. Physically it is a ZIP archive, so it carries the same PK header as any .zip file and extracts the same way.
The format comes from NIEM, the National Information Exchange Model used across United States government agencies for justice, health and emergency-management data sharing. NATO later adopted the same package and registered the media type application/vnd.nato.openxmlformats-package.iepd+zip. Inside every IEPD is a required catalog file, iepd-catalog.xml (named mpd-catalog.xml in older Model Package Description versions), which indexes and describes each artifact so a receiving party can implement the exchange without outside references.
Alongside the catalog you find subset and extension schemas written as .xsd documents, sample .xml instance files, business rules and a change log. The catalog is what turns a plain archive into a valid IEPD.
Security & safety
RISK: LOWAn .iepd is a ZIP archive of schemas, XML and documentation, so it carries no executable code and is safe to open. The usual ZIP caution applies: extract to a folder and be wary of unexpected packages from untrusted senders, since any ZIP can hide oversized or deceptively named entries.
Format details
in a nutshell- NATO Core Metadata Specification IEPD - NATO uses the same .iepd extension and registered the IANA media type application/vnd.nato.openxmlformats-package.iepd+zip for defense information-exchange packages under ADatP-5636.
Programs that open IEPD files
Windows3 apps
7-Zip
Open-source Right-click the .iepd file and choose 7-Zip > Open archive to browse the catalog and schemas without renaming anything. 
Windows File Explorer
Built-in Rename the file to .zip, then right-click and choose Extract All to unpack the package. 
macOS2 apps
The Unarchiver
Free Open the .iepd with The Unarchiver to expand it into a folder of schemas and XML instances. 
Linux2 apps
NIEM Tools / IEPD tooling
Free Upload an IEPD ZIP to validate its catalog and inspect its NIEM conformance online. Technical details
deep spec| Encoding | Binary ZIP archive wrapping XML, XSD and text artifacts |
| Byte order | N/A (ZIP container) |
| Container | ZIP (DEFLATE compression, same structure as a standard .zip archive) |
| Compression | DEFLATE, as used by ZIP |
| Encryption | None defined by the specification; the archive is not encrypted |
| Typical size | Tens of kilobytes to several megabytes, depending on the number of schemas and sample instances |
| Structure | A self-contained ZIP archive with a root directory containing a required catalog file (iepd-catalog.xml, historically mpd-catalog.xml) that indexes all artifacts, plus subset schemas, extension schemas, sample XML instance documents, documentation, business rules, change logs and a conformance/README file. |
| Integrity | CRC-32 per entry, inherited from the ZIP format |
| Platforms | Windows, macOS, Linux |
| Notes | The catalog XML is what makes the archive a valid IEPD rather than a plain ZIP; validation tools read it to locate and type every artifact. The schemas are W3C XML Schema (XSD) that constrain and extend the NIEM reference model. |
| Spec Family | NIEM Model Package Description / IEPD Specification; NATO ADatP-5636 NATO Core Metadata Specification |
| Released | IEPD concept dates to the early NIEM effort (mid-2000s); the format was formalized in the Model Package Description Specification and later renamed to the IEPD Specification 5.0 (2021). NATO registered the IANA media type in 2023. |
| Latest version | IEPD Specification 5.0 (NIEM, 2021) |
| Open standard | Yes · royalty-free |
| Specification | niem.github.io |
IEPD conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about IEPD files.
Frequently asked questions
How do I open an .iepd file?
.zip first and extract it normally.Is an .iepd file just a ZIP file?
PK signature and extracts like any other ZIP.What is inside an IEPD?
What is the difference between an IEPD and an IEP?
Who uses IEPD files?
Can I edit the schemas in an IEPD?
.xsd and .xml files with an XML or schema editor, then re-zip the folder and rename it back to .iepd, keeping the catalog in sync.
