None of it is taxable if he did not itemize in 2017
Step-by-step explanation:
Whether you subtract the tax on state and local taxes in lieu of the state income tax in Schedule A in the intervening year or have taken the prescribed deduction, you do not have to record the amounts in Box 2, which did not increase the federal tax for that year.
The 1099 G is most commonly used to report unemployment benefit and any tax refunds received by the state or local authorities in the same year.
You may need to report some of the information you have in their tax return if you received a 1099-G form this year from a government agency.