My wife and I both lived in Texas in the beginning of 2019, but I accepted a job in Maryland in April 2019. We've decided to live apart for a while so only I moved to Maryland. I had an stock investment account that I transferred to my wife in March so she could take care of the investments from Texas. If we file a joint federal tax return and individual state returns, do I need to show capital gains from my wife's investment account on my Maryland state return?
If you are filing the joint return for federal but separate for Maryland, you must attach a pro forma Form 505 and Form 505NR and only she would report the income on the NR.
Would my wife owe taxes on income reported on Form 505NR?
Only your wife's Maryland state-source income would be taxed by Maryland- so the interest and dividends would be Texas income. @mover20