It's on page 15.
Offset of QCDs by amounts contributed after age 701/2. Beginning in tax years after December 31, 2019, the amount of QCDs that you can exclude from income is reduced by the excess of the aggregate amount of IRA contributions you deducted for the taxable year and any prior year that you were age 701/2 or older over the amount of such IRA contributions that were used to reduce the excludable amount of QCDs in all earlier years.
