How should I file my taxes if I rented a room for 75% of the year and then rented the full unit (2BR) for the remaining 25% of the year?

[Carl]

Please provide some additional clarity here, so there's absolutely positively no doubt of what you're talking about here.

Are we referring to rent that you paid? Or rent that you charged and received? I am assuming this is for rent you received for renting out the space in your primary residence. If any part of my assumption is wrong, then please clarify.

[RayW7]

You would file your rental income and expense on Schedule E.  

Regarding the income, it should be straight forward as that would be total amount collected.

You would have to do the math to prorate the expense, which could be based on square footage.  Then you would allocate the percentage of the expense amount while just renting the room. 

The software will complete and file the Schedule E with your return. Follow the steps below to enter your information for TurboTax to create a Schedule E. 

To enter information for royalties or rentals, please follow the steps below. 

1. Federal Taxes tab (Business tab in Home & Business)
2. Select Wages & Income
3. Scroll down to Rental Properties and Royalties
4. Select Start next to Rental Properties and Royalties (Schedule E)
5. Follow the prompts to enter your royalty information. 

-for additional information on schedule E follow this link-

Video: Filing Schedule E Supplemental Income ... - TurboTax

[Carl]

For your situation, if it's rental income to received, its not as straight forward as one may think. You'll basically have two rental property entries on the SCH E, and because of a "quirk" in the program that is not feasible to address by the programmers, one of the figures you enter will be the wrong figure, and you won't even know it. The program "final checks" will not flag it either.