There is no deductible of anything on SCH E for the property or during the time the property is not in service.
Your only deductions for the period of time "before" you placed the property in service, are property taxes and mortgage interest. That's it. Those are a SCH A itemized deduction.
Additionally, the deductible amount of property taxes and mortgage interest and property taxes are prorated so the allowable amount you can claim is split between SCH E for the period of time it was classified as a rental, and SCH A for the period of time it was not.
Also, you have to manually pro-rate the property insurance. Whatever portion of property insurance you paid for the period ot time it was a rental is a SCH E deduction. But property insurance for the period of time it was not a rental, is not deductible at all, anywhere on your federal tax return.
Just keep in mind that until the total of all your SCH A itemized deductions exceed your standard deduction, it has no impact on your tax liability. Additionally, there are limits on some things you may claim as an itemized deduction on SCH A. For example, SALT (State and Local Taxes) paid are limited to a maximum of $10,000. Any SALT paid over that amount is just flat out not deductible on the federal return. (May be different for your state return, if your state taxes personal income.)
Typically, if you just work through the program the way it's designed and intended to be used, while using the guidance I provided earlier so you don't "misinterpret" or miss anything, it all works out in the wash. But I can't stress enough the importance of reading the small print on each and every screen as you work it through.
