Of 3 IRA RMD's that I rcvd, only the inherited Roth shows on line 4a. The other 2 trad IRAs are included on 5b. Taxes don't change, but should I amend my return?

[BillM223]

I assume you meant the other two trad IRAs are included in line 4b, not 5b.

The instructions for lines 4a and 4b are a bit convoluted. For example, if the entire amount of a distribution is reported in 4b, then the distribution does not have to be reported in 4a, which leads to the seemingly strange situation of 4a being smaller than 4b.

Not to worry - as you suspect, this will have no impact on your tax return.

[dmertz]

The gross amount of the inherited Roth IRA will be included only on line 4a if the taxable amount of the distribution is zero.

Only amounts distributed from IRAs appear on line 4a/b.  If the Forms 1099-R provided by the payer for the distributions from the traditional accounts do not have the IRA/SEP/SIMPLE box marked, those accounts are not IRAs and belong on line 5a/b.  If these forms do have the IRA/SEP/SIMPLE box marked, go back and mark the IRA/SEP/SIMPLE box on TurboTax's forms to agree with the marking on the forms provided by the payer.