I sold a personal residence at a loss in 2016 but forgot to report it. Can I report the sale and loss on my 2018 return or do I need to amend 2016?

[vrav]

I owned the property for less than 2 years.

"I sold a personal residence at a loss in 2016 but forgot to report it. Can I report the sale and loss on my 2018 return or do I need to amend 2016?"

[DoninGA]

The sale of a personal residence at a loss is not reported on a tax return.  Unless you received a Form 1099-S for the sale then it must be reported (gain or loss).  Although with a loss no taxes will be owed.  If required to be reported it can only be reported on a tax return for the year of the sale.