4 Years ago would be when congress and the then president passed legislation that changed the Federal tax laws. If you itemize now and the standard deduction his higher than schedule C, it takes the standard deduction so your mortgage is not used to figure your tax obligation.
I don't like it either, because all they did was pump up the standard deduction after they took your personal deductions away so it would interfere with take schedule C and your personal deductions which would have been more than the standard deduction before and you would be paying less taxes for most middle income people that is. I'm retired and it increased my taxes too. It benefits the higher income because they of course have very big mortgages to claim, but they don't get the personal exemption but they don't need it and they got the child credits. They really skewed things up! The rich got the big bang from all that!
