Contributions to pending 501(c)3's

Is a charitable contribution to a pending 501(c)3 corporation deductible even if the organization has not yet received a favorable determination letter from the IRS, but the application (Form 1023) has been filed in a timely matter. This organization is incorporated in the state of California.

Thank you.

As a technical matter,...yes.
As a practical matter,...maybe.

Status under §501(c) is a question of fact & law. A Determination Letter is only the IRS's acknowwdgment of that status, and is granted retroactively.

The risk is that the IRS will not grant Status, and litigation is necessary to determine the Entity's status.