If your firm's 401k plan allows it, you can contribute up to 32k post tax (it's not deductible) and then immediately roll over to a Roth 401k (google for "mega-

If your firm's 401k plan allows it, you can contribute up to 32k post tax (it's not deductible) and then immediately roll over to a Roth 401k (google for "mega-backdoor Roth"). People don't realize that the IRA and 401k sections of the tax code are completely different, and they both have Roth sections, and the limits in one don't apply to the other.