The rule was in effect for 2019 filing. If your 2019 tax return included a Rental Activity Safe Harbor Statement, that statement had to be signed and dated and included with a "printed and mailed" tax return. TurboTax could not attach a PDF for the Rental Activity Safe Harbor Statement to an e-filed 2019 tax return.
To remove the safe harbor:
In TurboTax Online, delete by going to the left menu, Tax Tools. Select Tools and Delete a Form. Scroll to find Section 1.263(a)-1(f) De Minimis Safe Harbor Election and Delete Form.
If you are in TurboTax CD/Download, go to forms mode and double click Open Form. In the search box, type election, scroll down to select De Minimis Safe Harbor Election. When it opens, uncheck the box.
If the form comes back up, go through your interview and see if it asks a question about accepting safe harbor and answer No to that question.
The safe harbor is a way to report expenditures of less than $2500 as expenses, rather than improvements. If is used for small businesses and real estate rentals.
[edited 2/20/2021 | 2:40 pm PST]
