In 2021, Idaho issued a one-time tax rebate to some residents. Do I need to list this rebate on my federal return, similar to a tax refund?

Yes, treat this as you would a state tax refund.

Since you received this state rebate in 2021, you’ll only need to include it in income if you deducted the tax in an earlier year.

Please see Tax Rebate: Frequently Asked Questions and State tax refund in the IRS’ 2021 Publication 17 for more information.