I just received an amended 1099-B for 2019 from my broker which shows my cost basis of some redeemed bonds was more than $3000 over what the original 1099-B said. Hence, the error is in my favor and will perhaps reduce my 2019 tax liability. Do I have to file a 1040X for 2019 or is there an easier way to offset it on my 2020 tax return? The problem is that the ripple effect will impact multiple QBI limit calculations, loss carryovers etc., (multiple forms 8995A's), all additional tax forms, and will again generate a 100+- page paper return. Any expert advice?
