You can't claim the $300 above-the-line Charitable Deduction in addition to the amount claimed if you itemize.
If you Itemized your Charitable Deductions are included in Schedule A .
The Cares $300 Charitable Deduction is only available if take the Standard Deduction.
Taxpayers who take the standard deduction can also now write off up to $300 in charitable cash donations in 2020 regardless of filing status. This increases to $600 in 2021 for married filing jointly. This is a new "above-the-line" deduction for people who claim the standard deduction.
