Answer:
The maximum state and local tax deduction is $10,000 for all combined state and local taxes paid during the year. That is the maximum amount that Jeff would be able to deduct if he itemizes. In this case, the maximum deduction would be = $5,000 + $3,500 + $1,000 + $450 = $9,950.
Unless Jeff has other applicable deductions, he would be better off by taking the standard deduction.