Yes, contributions to Traditional IRAs may be deductible, and reduce your taxes. Contributions can be made to your Traditional IRA at any time during the year, or by the due date for filing your tax return in the year following that tax year (not including extensions). (For tax year 2017, your tax return is due April 17, 2018.)
If you contribute between Jan. 1 and April 17, be sure to identify to the financial institution that the contribution payment is being made for the 2017 tax year, and not for the current 2018 calendar year. You can claim a deductible contribution or report a non-deductible contribution (Form 8606) on your return even if you haven't made the contribution yet, provided you make the IRA contribution (it is funded) by the return's due date.
How much of my Traditional IRA contribution is deductible? https://ttlc.intuit.com/replies/3301534
