Wednesday, September 25, 2013

Ruminating on EDI

Despite being very old, EDI (Electronic Data Interchange) is still a dominant force in many industries; especially in healthcare. Organizations have invested so much in EDI, that it's not economically practical to shift to other standards such as XML.

A good primer on EDI is available at:
http://ondisplayapparel.com/whitepapers/What_is_EDI_Whitepaper-Taps.pdf

There are two popular standards for EDI: X12 and EDIFACT. X12 was designed as the standard for EDI transactions in US, and EDIFACT emerged out of X12 for international use. EDIFACT is a global EDI standard supporting multi-country and multi-industry exchange. There are a lot of differences between X12 and EDIFACT, one important difference being the fact that X12 assigns numeric values to documents whereas EDIFACT lists names or abbreviations.

In the EDI world, we have the concept of a VAN (Value Added Network). VANs are service providers that act as messaging hubs between trading partners and handling the EDI communication.

A EDI interchange message is made up of "Segments" and "Elements". Each segment begins with a two- or three-word identifier (ISA, GS, ST, N1, REF) and ends with a delimiter. The elements within each segment are also separated by a different delimiter. A good example for HIPAA X12 Claim transaction is available here