Home & Business Senior Deduction

The new additional senior deduction for seniors married filing jointly adds $12,000 to the standard deduction, an amount that goes down by 6% for any amount by which the MAGI exceeds $150,000.  My desktop TurboTax Home & Business appears to be using 12%.  I simply wish to report the issue.  I noticed it as I was trying to assess the year-end IRA draws I wish to do.