Final answer:
To estimate Deon and NeNe's AMT, certain itemized deductions they claimed must be added back to their taxable income, including state income taxes, real property taxes, miscellaneous deductions, and non-qualified mortgage interest.
Step-by-step explanation:
To calculate Deon and NeNe's Alternative Minimum Tax (AMT), we first need to identify the adjustments and preferences that apply to their situation. For the Alternative Minimum Tax calculation, certain itemized deductions are disallowed, such as state income taxes and property taxes, also known as 'tax preference items.' Furthermore, miscellaneous itemized deductions subject to the 2% AGI floor are not allowed for AMT purposes. Hence, from the itemized deductions provided, we must add back the state income taxes of $41,400, real property taxes of $17,700, and miscellaneous itemized deductions of $8,400 to their taxable income. However, charitable contributions and mortgage interest on debts to buy, build, or improve a home are deductible for AMT. The interest on the home-equity loan used to buy a new car, which amounts to $14,800, is not deductible for AMT purposes, so this amount should also be added back to the taxable income.
In summary, to compute the AMT, we'd take their taxable income of $854,000, add back the disallowed itemized deductions for AMT purposes ($41,400 + $17,700 + $8,400 + $14,800), and then apply the AMT tax rates per the relevant AMT tax brackets to determine the potential AMT liability. However, without knowing the exact AMT exemption amount and phase-out thresholds for 2017, as well as the AMT tax rates, the calculation cannot be completed in this response. Still, the process outlined here is essential in determining Deon and NeNe's AMT liability.