This article is helpful about how to do married filing jointly for federal and married filing separately for states (we live and work in different states.) https://ttlc.intuit.com/questions/1901214-how-do-i-prepare-a-joint-federal-return-and-separate-state... I followed these instructions verbatim and am now largely good to go. However, DC requires you to send your 1040 and your 1040 - A to them when you submit your "state" (aka DC) taxes. Should I send the "real" MFJ tax return or the "mock" MFS tax return to DC with my DC tax submission?
