If the CD is in a tax-deferred or tax-free account, such as an IRA or Roth IRA, interest on the CD is not currently taxed; the rollover of the CD when it matures is not a taxable event. If the CD is in a taxable account, interest is taxable, but again rolling over the proceeds when the CD matures is not a taxable event.
Items directly reducing income. Personal deductions such as for mortgage interest, state and local taxes, and charitable contributions are allowed only if deductions are itemized on Schedule A, but deductions such as for alimony, capital losses, moving expenses to a new job location, business losses, student loan interest, and IRA and Keogh deductions are deducted from gross income even if itemized deductions are not claimed.