<prompt> Human: I see a lot of posts telling people in their 40s and even higher to start a Roth IRA401k. We need to realize that a Roth is simply a tool for tax diversification over a lifetime.I would say people in their 40s-50s are in their peak earning years and therefore paying their highest marginal tax rate. A Roth is only a good idea if the person is expecting to withdraw more more per year from savings in retirement than they are presently earning. For someone in their 20s, this is likely a no-brainer, but for people in their peak earning years, they will likely have to withdraw less per year from savings than theyre currently earning. Why pay taxes on that savings now when they will pay the highest price?Of course, another argument would be that if we expect marginal tax rates to go up in the future, it would make sense to pay that tax bill now. However, the more someone is currently making, especially if they are in middle age, the weaker the argument is for a Roth.  <response>: FAQ: Roth or Traditional?Especially rPFs definitive post on the topic 