The only way I can see to make this work, is apply the credit for 2014, to 2015. File an amended return for 2015. The enter the resulting excess payment (and too small refund) for 2015 as a credit for 2016, in line 65 of 1040, for my 2016 return.
Similarly, I will have to start a new *.tax15 file, from the changed *.tax14 file. Then use the amended *.tax15 file, as the starting point for my *.tax16 file.
Is there an easier way?
Yes, there's a much easier way. On the 2014 amended return, apply the refund to 2016. On your 2016 tax return, enter the refund from the 2014 amended return as a 2015 refund applied to 2016. This is what the IRS instructions and the TurboTax "Learn More" help say to do. The year of the amended return that it's coming from doesn't matter. Amounts applied from any amended return all go in the same place on the 2016 tax return.
Do not amend your 2015 tax return or attempt to make the 2014 refund flow through 2015.
Yes, there's a much easier way. On the 2014 amended return, apply the refund to 2016. On your 2016 tax return, enter the refund from the 2014 amended return as a 2015 refund applied to 2016. This is what the IRS instructions and the TurboTax "Learn More" help say to do. The year of the amended return that it's coming from doesn't matter. Amounts applied from any amended return all go in the same place on the 2016 tax return.
Do not amend your 2015 tax return or attempt to make the 2014 refund flow through 2015.
It would be helpful if you keep your related questions in one thread. If you have any further questions about applying the refund from your 2014 amended return to your 2016 tax, please add a comment to this thread. Do not post another separate question about the same topic.