Enter the address where you both last lived together, if you currently reside together you should enter that address. If you previously indicated that you live together currently, we have pre-populated the date field as "PRESENT" for you. USCIS wants to know if you have lived together because typically as a married couple you do reside together.
If you don't currently reside together or have not previously lived together you should go back to the beginning of the section (Marital History and Co-Habitation) and indicate as such.
We encourage you to fill this part out correctly to avoid issues.