AMT problems with carryovers 2025

An update to my post.  A huge bug in Turbotax!

If you find that you are subject to AMT this year but have never had AMT in past years ,and also don't have a huge income or huge gains without losses for this year, you need to look at the capital gain carryover worksheet and make sure that whatever losses you had from last year are the same in the regular tax column and the AMT column. If you've had AMT in the past, I can't help you because I'm not sure what to do then, but if you've NEVER had AMT, you can follow this post.  When figuring your tax, regular tax carryovers are applied first to determine your tax liability which should be pulling from the regular tax column first but instead it's pulling from the AMT column which has all those old AMT calculations from the year before.  If it was don't properly Turbotax should apply your regular carryover and only if after that it sees you have too much income or gain should it try to calculate AMT. (that's when you'd need AMT credits).

With the regular carryover my taxes were $2000... with the flawed AMT carryover they were $25000. I spent weeks researching this and going through every line and all the schedules of my tax return and then alot of time on the phone with Turbotax to confirm that there is an error in the program.

The fix:

First I created a duplicate file just in case I messed up. To do this you open your file in the program, then click on file, duplicate, to create a new file. I renamed the new Turbotax file to something that wouldn't confuse me, closed the program, and opened it again with that new file (so if I made a mistake I wouldn't lose all my hard work). With the new file open, I then went to forms, and deleted the carryover loss worksheet and form 6251 (which is another form that figures AMT). I then went back to EasyStep and clicked on Wages and Income, Investment Income, and the capital loss carryover section... following the Easy Step prompts to enter my capital loss carryovers from the year before. You can find them on last year's Schedule D under short-term and long-term carryovers or from the capital loss carryover worksheet under the regular tax column, but I wanted to confirm they were correct from last year. This forced Turbotax to create a new capital loss carryover worksheet which had the correct information on it. Then I went back to forms and pulled up the capital loss carryover sheet and saw that the AMT column was now populated with the same info as the regular tax column. There was also no form 6251 anymore now because I didn't need it.  Then I went to Other Tax Situations, AMT and in my case I did not owe AMT. I then checked my Schedule D and it was clear that my losses from last year offset my gains correctly. 

If you do have some big gains you could be subject to AMT but to find that out you need to have the carryovers correct first because they may be able to offset your gains and would lower your AMT if you have it. Good luck