I received multiple 1099-Gs for years 2016, 2017, & 2018, from the State of Maryland, because I found a Pension Exclusion deduction that I had not taken. (I also received a 1099-G for 2019.) In 2020, I amended 3 State Tax Returns (2016, 2017, & 2018), but did not amend the corresponding Federal Tax Returns. Do I have to amend the corresponding Federal Tax Returns? While entering the 1099-Gs in my 2020 Premier Turbotax, under "Tell us about your refund", I am asked for A. the "Total Refund Received in 2020", B. the "Total of all your payments and withholding", and C. the "Tax Year of Refund". How do I compute these numbers for each of the 2016, 2017, and 2018 1099-Gs that I received from Maryland?