Tax Deductible Contributions
HSAs allow you to legally avoid federal income tax by saving 100% of the health plan's deductible, up to $3,400 for singles or $6,750* for families, into your HSA account for 2017. Whatever you deposit into your account up to April 15, is an "above the line" tax deduction for the previous year's income taxes, meaning you get a federal income tax deduction for money you put in even if you dont itemize deductions. If your employer makes an HSA contribution for you, it is excluded from income, and not subject to any income tax or FICA
Either way, this will immediately reduce your federal income tax due for the year. Most states also allow the same deduction for state income taxes.
*maximum for a family. Individuals over age 55 may deposit into their account and take a tax deduction of an additional $1,000.