.Everybody is allowed a $13,850 standard deduction ($27,700 married), from income, before tax is calculated.
Alternatively, taxpayers are allowed to itemize deductions (mortgage interest, medical expenses, charity donations and state-local taxes paid, medical expenses). If your itemized deductions don't add up to more than $13,850, you get the $13,850 standard deduction. No body gets less*, but some people get more.
*There are special rules for people who can be claimed as dependents
