Getting a tax deduction from the Internal Revenue Service in the form of a personal exemption amount for the taxpayer, spouse, and children or other dependents is necessary each year. This deduction allows the individual taxpayer to be able to calculate his or her federal income tax. The Internal Revenue code that discusses the personal exemption deduction can be found at Title 26 of the United States Code. Personal exemptions help the taxpayer to determine what his or her taxable income will be. Once this amount of income has been calculated, what is left is the taxable income amount. Tax rates are applied only to this amount in order to find out what the amount of income tax the taxpayer owes or is due to be refunded.