The fact that you have a 401K in your new job means that a deductible contribution to a Regular IRA may be limited. The actual limits for 2013 will depend on some if you are single or married, and does your spouse also have access to a retirement plan at work.
Assuming single:
- Modified AGI less than 59K IRA Fully deducible
- Modified AGI 59K to 69K IRA partially deducible
- Modified AGI greater than 69K No deduction
If you are married the limits are different. But your spouse could also make a contribution to the Regular IRA. Their contribution may or may not be deductible as a separate calculation from your case.
The best part is that the deadline is April 15th 2014. The contribution limit is 5,500 for 2014 or 6500 if 50 or over.
A Roth IRA doesn't get you the deduction you are looking for.
The only other options I can think of is making your January mortgage payment in December.
Keep in mind if you are married and 50 or over you can make $13,000 in contributions, in the 25% tax bracket that will reduce your tax bill by $3,250 which is still far from $15,000.
Ask your accountant if you will owe penalties for underpayment.