26 CFR 25.2523(h)-1 - Denial of double deduction.
The value of an interest in property may not be deducted for Federal gift tax purposes more than once with respect to the same donor. For example, assume that D, a donor, transferred a life estate in a farm to D's spouse, S, with a remainder to charity and that D elects to treat the property as qualified terminable interest property. The entire value of the property is deductible under section 2523(f). No part of the value of the property qualifies for a charitable deduction under section 2522 for gift tax purposes.