In 2017 my fiance and I acquired a rental property. We married in 2018.
We split income and expenses 50/50 in 2017 and allocated 50% of the value on each of our returns.
Filing a join return in 2018, the basis should now be doubled combining both of our shares.
You are correct in that the basis should now be basically doubled.
You are correct in that the basis should now be basically doubled.