After filing my 2024 Federal and state returns and receiving both refund checks I received a corrected 1099-B from my brokerage firm's investment fund which adjusted the cost basis of several stock sales transactions. It resulted in and increase of LT Capital gain of $330 and Taxable Income and Federal Tax due of $49 and State tax of $12. Aside from the 1040-X for Federal, the State's AMD form and an explanation of the reason for the amended returns, what other forms do I need to attach to the Amended returns?
Also, am I subject to any interest or penalty even though this issued was not my fault?
Thanks for any input and guidance.
