A word of CAUTION and the TT work around I found this year.
Turbo Tax for South Carolina Tax Return fills in the SC "Additions" form for Federal/State Depreciation differences seemingly automatic. i.e. you can't change the figure and it took me several years to figure out how and where it is calculated. In the "step-by-Step" format I never saw any question asked on this issue. However if you switch to the "forms" view and find the Asset Wks on every depreciated item for every Out of State rental, you can scroll down to the State/Fed calculated number. Just below this are Yes and No check boxes on "Should this be included on State return?".
On the top of each form is a place for the selected State which in my case was SC. TT assigned mst of my rentals to SC although the state is given on each one and TT suggests that I file state returns in each state mentioned correctly! Anyway, if your rental is not in SC, like most of mine, TT had the YES box checked. Check the NO box and boom, The unchangeable Additions box is recalculated to include only the SC rental properties.
In past years I have been on the phone with TT help trying to explain this issue which I though was an error in TT. At that time I had no rentals but out of state ones and TT was adding big $'s to my SC income!! If anyone else was having this problem, or has not noticed this costly error, I hope this will help.
Cheers,
BuddyTT & BuddyTT2