The 2016 return of a Roth IRA contribution made in 2015 should have codes J and P.
TurboTax's drop-down box text assumes that you are entering a 2015 Form 1099-R. In this case, you are entering a 2016 Form 1099-R, so code P means taxable income for 2015. In other words, code P for a distribution from an IRA always means that the distribution of the returned contribution occurred in the year following the year in which the IRA contribution was made. A 2016 Form 1099-R with codes J an P means a the return in 2016 of a Roth IRA contribution made in 2015.
