Home Mortgage Interest
It used to be any mortgage interest you paid was deductible. Not true anymore. Now if you have a mortgage in excess of $1,000,000 for marrieds or singles, or $500,000 if married filing separate. Any interest expense paid on indebtedness over this amount is non-deductible on your tax return per the IRS. Hence this is the reason they stick the mortgage balance on those annual statements now, so this can be allocated.
Often this will affect higher earning professionals or self employed people with larger incomes. The IRS is alert to this new facet of tax law also.