The charitable deduction is limited when the gift makes up a large percentage of your income. Beginning in 2020, you can deduct cash contributions in full up to 100% of your AGI to qualified charities, donations of property up to 30% of your AGI and appreciated long-term securities worth up to 20% of your AGI. Anything in excess of these amounts can be carried forward to the next tax year, for a maximum of five years.
Here is a TurboTax article about Charitable giving and how it works.
