I believe it should be $600 for Married Filing joint.  I am awaiting a software upgrade to include an extra $300 for joint returns. Between Federal and state it can make a difference of $42 on many return more on others.   I am cutting and pasting below some information recently received from a seminar I took regarding this.  Or maybe this is for next year's return since it states for taxable year beginning in 2021 ??????

Special Charitable Deductions - Section 212 – Amends §170:
 ‘‘SPECIAL RULE FOR TAXPAYERS WHO DO NOT ELECT TO ITEMIZE DEDUCTIONS.—In
the case of any taxable year beginning in 2021, if the individual does not elect to itemize deductions
for such taxable year, the deduction under this section shall be equal to the deduction, not in excess of
$300 ( $600 in the case of a joint return), which would be determined under this section if the only
charitable contributions taken into account in determining such deduction were contributions made in
cash during such taxable year (determined without regard to subsections (b)(1)(G)(ii) and (d)(1)) to
an organization described in section 170(b)(1)(A)).

To the experts out there...Please advise