It was never claimed.  Tax returns were self prepared in previous years.  Folks think just because they don't claim depreciation that when they sell the rental that the basis won't be reduced.  But it is "allowed or allowable".  This almost seems too good to be true.  Confirm for me that since there was NO depreciation claimed that they can take a negative adjustment for what would have been the total depreciation since they put the house into service.  Seems too good to be true.