After entering my 1099-R, I got this question: 'Did you make after-tax contributions to a 401(k) or 403(b) plan?'. It's unclear which 401(k) and year this is referring to

[pmeyerk1]

I rolled over a former employer's 401k to a Roth IRA in 2023. I also had other 401(k)s in 2023.

[dmertz]

TurboTax is asking with respect to the 401(k) from which the distribution being entered was made.  Any after-tax amount should be present in box 5 of this Form 1099-R.  Each 401(k) is independent of the others.