TIRA nondeductible IRA conversion of 6500 ends up being taxed when the TIRA contribution for 2017 was done in January 2018 with immediate conversion. Basis was 0. Why?

[moandjim]

If I do not indicate the contribution was in 2018, it is not taxed. I made both the 2017 and 2018 contributions Jan 2018. Immediately did a back door Roth conversion. No 1099-R or 5498 until May from Fidelity per them. If I do a substitute with correct data, still taxes me on the 6500. (I'm over 50). I know this to be incorrect as the law for conversions has not changed. I have done it every year since original taxable conversion in 2012ish. It is infuriating. I can't change it. Can't get it to do the "taxable IRA distribution worksheet" that reconciled this in 2016 filing last year. Any ideas? If I just do not fill out the 1099-R it is fine.

[macuser_22]

If you did the Roth conversion in 2018, then it will be reported on a 2018 1099-R that you will receive next January.  You report that on your 2018 tax return.  You cannot report a 2018 conversion on a 2017 tax rerun.  he only thing that goes on your 2017 tax return is the non-deductible Traditional IRA contribution which will produce a 8606 form with the non-deductible contribution on line 1 and carry forward non-deductible basis on line 14 that you will enter next year when you report the 2018 1099-R.

[AmandaR1 · Accepted solution]

If you didn't receive a 1099-R, then you should not enter one this year. Instead, you'll have nondeductible contributions to your IRA on form 8606 for 2017. Next year, when you enter your form 1099-R, your nondeductible contributions will offset your Roth conversion. 

For tax year's 2017 and prior, the Roth contributions can only be allocated to the year in which the conversion was made. Since your conversion was in 2018, Roth contributions must be reported in 2018. 

In the past, possibly your investment firm classified it differently. If they issued the form 1099-R for the prior year, then you could report your contributions as made in the following year (as long as within 60 days). Ultimately, the tax treatment stems from when they issue you the form 1099-R. 

In either case, it will have the same affect on your taxes.