The information in the Tax Calculator is based on current tax law with some updates for anticipated changes. The calculation currently accounts for the increased limit on medical expenses for itemized deductions (medical expenses must exceed 10% of AGI in 2017). It also accounts for the Additional Medicare Tax and the Net Investment Tax.
Due to the complex nature of determining the potential penalty for not having coverage and the potential tax credit for those in certain income ranges to help pay for health insurance, these items are not accounted for in the Tax Calculator. Note: The potential penalty and credit will not apply until the 2017 tax year.
The IRS Affordable Care Act Tax Provisions
page provides more information on how the Affordable Care Act affects individuals, employers, and other organizations.