Question for all you 401k plan experts out there.
I just had a conversation with my HR benefits manager. I asked him about the mega backdoor Roth IRA contribution discussed by the MadFientist. He said we're permitted to make after-tax deductions and could roll them directly to my Roth. My only question remaining is this - can I make those after-tax contributions with money that's doesn't come from my paycheck? I'd like to make one, lump sum contribution of $30,000 ($53,000 - $18,000 - $5,000 of employer contribution = $30,000) rather than having a few thousand deducted from my paycheck over the course of the year. The reason I prefer to do it all at once is that I can roll it over the next day and know that I will have minimal tax consequences vis-a-vis gains or losses. However, if I contribute from my paychecks over the course of the year, then those gains or losses could be hugely variable. Do 401k plan administrators allow that?