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.
A statutory term describing the cost used to determine your profit or loss from a sale or exchange of property. It is generally your original cost, increased by capital improvements, and decreased by depreciation, depletion, and other capital write-offs.