Depending on your income, between 15 and 100 percent of Social Security retirement benefits may be tax free. But you do need to pay tax on some income that you might assume to be tax free. Uncle Sam often gives a break to married folks. That may apply to a divorced or widowed parent caring for a child, or a single taxpayer caring for an elderly parent. A head of household pays tax roughly in between the amount of the levy on a single and a couple.
Couples usually do best combining their income and deductions on a joint return.
But a controversial twist in the tax code can sour the mix of marriage and taxes. Though the tax paid by a couple will be less than that paid by a single person with equivalent income, two singles who marry may pay more tax in total than they did individually before the ceremony. That marriage penalty reflects the way tax rates are applied and the way deductions and other breaks are allocated. But for many, there's a marriage bonus. When one spouse didn't work before marriage, or earns a lot less than the other partner, total tax after marriage can drop, since some of the income of the higher-income spouse benefits from a lower married tax rate.