Married filing jointly is a tax filing status available to married couples in the United States. When couples choose this option, they combine their incomes and file a single tax return, which can often lead to lower tax rates and increased deductions compared to filing separately. This filing status allows couples to take advantage of various tax benefits, such as higher income thresholds for tax brackets and eligibility for certain credits like the Earned Income Tax Credit. To qualify, both spouses must agree to file jointly and report all income, deductions, and credits on the same return.