You generally won't be able to donate the shares until they vest.
In case you aren't aware, donating shares only lets you avoid any long-term capital gains taxes on those shares. This can be a great move if you intend to donate to charity anyway and you have some shares that have increased in value by a significant amount since you acquired them. But for RSU shares that recently vested, any capital gains at this point will be minimal. Donating new shares will be about the same tax-wise as selling the shares and donating cash.
Ah ok, this is a little different than I was thinking.
Let say I have a $10k grant that vests in April, which has grown to $11k, and $3k is automatically taken out for taxes. Is there no way for me to donate the entire $11k (pre-tax)? Only the $1k gains will be tax-free for a DAF?
Cost basis is $0 because I got the grants for free.
If this is the case, I probably won't donate any RSUs. Maybe I'll just donate index funds in existing taxable accounts that already have high capital gains.