The check was written in Dec of 2016, but it took awhile for everything to process and the roth 401k it was "rolled over" into did actually deposit the check until 3/3/1/17. We received a 1099R from the ESOP for 2016, but it seems to me like it should be on the 2017 tax year. Thanks for your help!
What is the code in box 7 of the Form 1099-R provided by the payer?
Code G indicates a direct rollover. Unlike an indirect rollover were the funds are first made payable to you personally, there is no time limit on delivering the check made out to your new retirement account for your benefit.
Because the distribution from the ESOP was made in 2016, it is reportable on your 2016 tax return.
You mentioned that it was rolled over to a Roth 401(k). Perhaps you meant to say that it was rolled over to a Roth IRA since a rollover from one employer's traditional 401(k) (including ESOP) to your Roth 401(k) account at another employer is not permitted. Taxable rollovers into a Roth 401(k) account are only permitted by In-plan Roth Rollover.
Assuming that the direct rollover was a proper rollover to a Roth IRA, this is taxable 2016 income.