Can I add a Roth option to my Solo 401(k)?

Yes — most Solo 401(k) providers now offer a Roth bucket for the employee deferral. You can put up to the full $23,500 employee portion in 2025 ($31,000 if 50+) into Roth, where it grows tax-free and comes out tax-free in retirement, with no income limit blocking you the way a Roth IRA has. The employer profit-sharing piece has traditionally been pre-tax, though recent rules now allow designating it as Roth too if your plan document permits. Roth deferrals make sense if you expect to be in a similar or higher tax bracket later, or if you want to diversify against future tax-rate uncertainty. You can also split — some pre-tax, some Roth — to hedge. Confirm your provider's plan document supports Roth before you elect it. See wealthserene.com/tools/roth-vs-traditional to weigh the tradeoff.