A traditional IRA can still be opened and funded for 2016, and potentially increase your refund.
You can always contribute to a traditional IRA, regardless of your income or coverage by an employer plan.
The deductibility depends on your income, filing status, and employer coverage.
These links provide the most recent income limits for deducting IRAs
IRA deductibility - covered by employer plan (the "retirement plan" box on your W2 is checked)
