I had an excess 401k deferral in 2018 for which I got an ROE in 2018. The refunded contribution is Roth and thus not taxable. But can I deduct a loss on that money?

[bummyguy]

Using example  numbers for illustration.  Let's say I had $1000 in excess Roth 401k deferral in 2018 and did an ROE for the $1000 in 2018.  But I had a $200 loss while that money was invested so my plan administrator only returned $800. I received a 2018 1099-R showing the distribution of $800 and Taxable amount (box 2a) of $0 since it was Roth and I already paid taxes on the contribution.  

Is the $200 loss deductible?  Seems like it should be given that I paid tax on it and then had an investment loss.  If yes, how to handle in TT?  (Note: seems like answer would be different for traditional 401k since in that case you would only pay income tax on the $800 returned versus the full $1000 you originally earned.  The $200 loss is "baked in" already).

[hbl3973]

IRS publication 525

https://www.irs.gov/pub/irs-pdf/p525.pdf

states on page 10:

Report a loss on a corrective distribution of an excess deferral in the year the excess amount (reduced by the loss) is distributed to you. Include the loss as a negative amount on Schedule 1 (Form 1040), line 21, and identify it as “Loss on Excess Deferral Distribution.”