The fact that you turned 70-1/2 will require you to take Minimum Required Distributions (MRD) from any Retirement accounts like IRAs & 401ks. That may or may not push you into a higher tax rate bracket. For tax rates see: <a rel="nofollow" target="_blank" href="
http://www.forbes.com/sites/kellyphillipserb/2014/10/30/irs-announces-2015-tax-brackets-standard-ded...>. Your "taxable income" is after deductions (standard or itemized) and exemptions.
