[mention://77326794
@TurboTaxBillMc] I wonder if you could find any basis for why the employer would do this (and it would be correct.) It seems like our taxpayer is going to be frustrated either way. One solution might be to report the excess contribution as listed on the W2, manually deduct the 2017 contribution, and then indicate in a statement why it is being deducted and declare that it will be entered as a correction on the 2017 return if that is what is needed. I think the IRS would take the position that it is the taxpayer's responsibility to file correctly, even if the employer has wrongly reported. Alternatively, the D 17 contribution could be coded as "other." Then it would not carry over to the contribution calculations. The rest of the scenario would still apply (statement, correction as needed to 2017 return, with reference to and documentation of the 2018 W2 on the 2017 1040x (amended return). Here is a relevant link, although not necessarily a clear answer as it is disputed:
https://accountants-community.intuit.com/questions/1332132-can-contributions-be-made-to-your-401-k-o...
