My original 2017 return is missing capital gains and losses reported by my brokerage on a 1099-B. I am filing an amended Federal return to claim a refund due to missing net capital losses. I have completed the 1040X which includes all the supporting documents (amended and original 1040, amended schedule D and the brokerage 1099-B).
I will also be filing an amended return to claim a refund from the state of Maryland. I am getting close to the deadline for the 3 year window so I need to submit both the Federal and State amended returns at the same time. When I file the Maryland form 502X, what supporting documents will the State require? My initial thought was to just include the 1040X in addition to the amended and original 502 and the amended and original 502SU. Should I include any additional Federal forms/documentation? Assuming the Federal amended return is processed and approved, will the state accept the amended 1040X without additional supporting documentation?
