For your specific and explicit situation, it is IMPORTANT that you work through the program the way it is designed and intended to be used. If you do not, changes are high your taxes will be wrong and it will be "YOUR FAULT" which is not covered under the TTX 100% Accuracy Guarantee.
WHen used the way it's designed and intended to be used, you can elect to have the program "do the splits" for you for those deductions that go on the SCH E for the portion rented, and those that go on the SCH A for the portion that is not rented. But pay attention to detail.
Some screens ask you for "whole house" expenses, while others will ask you for those expenses that are 100% related to the rental portion only. Generally, all of your rental portion only expenses will be zero, and your "whole house" expenses will be more than $0.
Then, based on the data you enter the program will do the splits "for you" based on the percentage of floor space you rented out, and the number of months it was a rental.
Here's some additional information you *WILL* need for clarification so that you don't make a "your fault" mistake.
Rental Property Dates & Numbers That Matter.
Date of Conversion - If this was your primary residence before, then this date is the day AFTER you moved out. If renting a room in your home, it's the day "AFTER" you stopped using the space for personal use.
In Service Date - This is the date a renter "could" have moved in. Usually, this date is the day you put the FOR RENT sign in the front yard.
Number of days Rented - the day count for this starts from the first day a renter "could" have moved in. That should be your "in service" date if you were asked for that. Vacant periods between renters count also PROVIDED you did not live in the house or use the room/space for personal use for one single day during said period of vacancy.
Days of Personal Use - This number will be a big fat ZERO. Read the screen. It's asking for the number of days you lived in the property AFTER you converted it to a rental. If renting a room in your home then it's the number of days you used that room for personal use AFTER you converted that room to a rental. I seriously doubt (though it is possible) that you lived in the house (or used the space if renting a part of your home) as your primary residence, 2nd home, or for personal use after you converted it to a rental.
Business Use Percentage. 100%. I'll put that in words so there's no doubt I didn't make a typo here. One Hundred Percent. After you converted this property or space to rental use, it was one hundred percent business use. What you used it for prior to the date of conversion doesn't count.
Now afer you work through all of the above, I would like you to help me identify a programming error with the program that only applies to *YOUR* specific situation. If you are successful in identifying the error (thus proving their is "in fact" a programming error) then I will help you to "fix" it so that your taxes are correct on this matter and won't delay any refund you may have coming.
Basically, go to IRS Publication 946 - How To Depreciate Property at https://www.irs.gov/pub/irs-pdf/p946.pdf
Then on page 36 of that document use the MACRS worksheet in the right column to manually figure your first year allowed deprecation. Get the percentage rate you need from table A-6 on page 70 of that document. If 2019 was your first year in service, then your percentage rate is in the first row, under the column for the month you placed it in service.
What you figure manually "should" be within $2 of what the program figures. But I'm expecting it to be off by quite a bit more, depending on the month you placed it in service in 2019. So if it's off let me know and I'll tell you what one date entry you made int he program, you need to change so that the program will agree with what you figured manually, within $2.
