It's basically about current tax bracket vs. tax bracket when you withdraw the money.. and it's pretty hard to beat 0% currently. Does your 401k offer a Roth 401k option, by chance? That would be your best way to shield substantial amounts from future taxes. Failing that, contribute to the match, fill up your Roth IRAs, and invest anything else you can in taxable accounts. Pick tax efficient options for any taxable accounts; fortunately, index funds are usually among the most tax efficient funds.