The payer must always put a zero in box 2a if they put code Q in box7. Code Q means that the distribution is nontaxable. When this is entered into TurboTax, TurboTax will include the gross amount on Form 1040 line 4a but will exclude the entire amount from line 4b. When entering this From 1099-R, be sure to indicate that the distribution is from an inherited Roth IRA by answering Yes when asked in the desktop version of TurboTax or by marking the checkbox for this purpose in the online version of TurboTax.
Regarding the RMD, if the distribution was sufficient to satisfy the RMD for the inherited Roth IRA, when TurboTax ask you to enter the required RMD, enter no more than the gross amount distributed.
