But, my gut feeling is that you can amend, to claim deprecation, going back 3 years, without that form.
If you used TurboTax for 2018 and 2019, then there's a good possibility that you did take depreciation and don't realize it. If (and that's a big *IF*) you did everything correctly per the guidance the program provided you, then the program will take care of depreciation stuff in the background and generally not bother you with the details. So you need to check your 2018 and 2019 tax returns. Chances are, if you did things right, you did "in fact" depreciate the property those two years and don't even realize it. Otherwise....
At this point in time you can amend back to 2017. You only need to go back to 2018 since you started renting in 2018. However, understand that this will require a "LOT" of manual work on your part.
- A prior year tax return can not be e-filed. This includes a prior year amended tax return. (IRS rules currently state this as of the date of my post here.)
Additionally, you "must" use the desktop version of TTX 2018 and 2019 to amend those two years.
Additionally, since you can not import information from a prior year tax return when you amend, you will have to print out the 2018 completed return and manually enter the "correct" depreciation numbers for "prior year depreciation" on your 2019 return, when you amend the 2019 return.
Then after you do all that, you will be able to import from your 2019 amended return, into your 2020 tax return if you complete the amending process "BEFORE" you start your 2020 tax return. It's a bit tricky to import from the amended tax file on your desktop computer, but it's perfectly doable.
