MIL trouble code, what does it mean

My 1999 Pontiac Grand AM SE showed a trouble code MIL. Can anybody tell me what that means and is that accurate. The guy who ran it said his computer for only up to 1995 so would the trouble code be accurate. He didn't know what MIL was. Appreciate any feedback on this.

Have a parts store read it, they will have the corret tool to use. Mil was displayed because up to 1995 most cars were obdI and 1996 and newer are obdII.