Background: Dual status filing for married clients. They abandoned US permanent residency during 2018.  Non residents on 12/31/18. Qualified for earlier residency termination date. Filing 1040 MFS for earlier part of year when they are residents. And filing 1040NR MFS for later part of year when they are non residents. Having read Pub 519, I understand that the 1040NR ("Dual-Status Return" on top) with no payment needs to be mailed in the Austin TX xxxxx-xxxx. But what about the 1040 return from the resident part of the year?

Does the 1040 needs also be mail in or can that be efiled?

If the 1040 needs to mail in, I assume to mail it to the regular regional address for 1040 for regular processing and not the Austin address for dual-status return processing, correct?