Original Script: http://www.vim.org/scripts/script.php?script_id=1625

A simple syntax highlighter for EDI X12 files - It does not validate the correctness of X12s. Just highlights the file. Currently only Healthcare 270/271/834s are tested.

Vundle install: In ~/.vimrc Add the following lines:

Plugin 'michaelachrisco/x12-syntax'
"Optional:
"au BufRead,BufNewFile *.x12 setfiletype x12
"au BufRead,BufNewFile *.270 setfiletype x12
"au BufRead,BufNewFile *.271 setfiletype x12
"au BufRead,BufNewFile *.834 setfiletype x12

Then do a :PluginInstall