Final answer:
Contributions to 501(c)(3) organizations are indeed only deductible for federal income taxes.
Step-by-step explanation:
The statement that contributions to 501(c)(3) organizations are only deductible when computing federal income taxes is true.
501(c)(3) organizations are nonprofit organizations that are exempt from federal income taxes. When individuals make contributions to these organizations, they can deduct those contributions from their taxable income when filing their federal income taxes.
However, it's important to note that this deduction is applicable only for federal income taxes, not other types of taxes such as state income taxes. Additionally, there are certain limitations and requirements for deducting charitable contributions, so individuals should consult the Internal Revenue Service (IRS) guidelines or seek professional advice to ensure they qualify for the deduction.