>>> import CoordConvertor >>> ct = CoordConvertor.CoordTranslator() >>> print ct.AsMGRS([36.279707,-77.266846],4,False) 18S TF 96401735
See the EditorTracker add-in here -- FloridaDisaster.org - US National Grid
Add X,Y, and USNG fields to your feature class, and at every add/update, coordinates are calculated.