Can increasing your 401k contribution decrease the amount of federal taxes and state taxes that you should pay for the year?
I know for a fact there is a savers credit for contributing to a ROTH IRA. My tax preparer was saying it only was for contributing to a traditional IRA but I did my research and was able to take advantage of it to not have to pay in at all to federal taxes. (I even got a few bucks back!)
It depends on your income situation for the savers credit.
For a traditional IRA, there is something but I am not well versed on exactly how that works. I would just recommend doing a little research to see exactly how that would work.
I found this article that might be helpful.
Also, @Lisa Eichinger was very helpful in answering tax questions I had this year.