In order to deduct the donation, you must itemize your deductions. Donations can lower your tax bill if you itemize deductions on Schedule A of your federal tax return. Since the Tax Cuts and Jobs Act of 2017 significantly increased the standard deduction, you should compare your total itemized deductions to the standard deduction to see which provides a greater tax benefit.
For cash donations to public charities, you can generally deduct up to 60% of your adjusted gross income(AGI). Since there are limitations to the amount you can deduct you may still owe tax after taking the deduction. This donation has nothing to do with the FICA tax and you will not get that amount refunded.
