Hello qbteachmt

I really appreciate your time and help 

You are really good numbers, math, and good explanation and give me examples

I understand now 

I prior thought wrong that all $6500 (tp is over 50) basic of cost in traditional IRA converted to ROTH (no IRA deduction subject to AGI threshold  in the year 2019) is not taxable income 2019

I did not computed prior traditional IRA basic  there and should be proportion of it  traditional IRA 2019 divided  (contribution traditional IRA 2019+prior traditional IRA basic)=% basic cost traiditonal IRA converted no taxable

Because tp did not give me info of 2018 traditional IRA basic before I have prepared 2019 return. Now I done with 2019 and find out 2018 tp had error and tp wanted me amended 2018. Then now I find out another mistake (because I saw form 5498 which meant tp should have IRA (traditional or ROTH)

Thanks lots