Open a Roth IRA and contribute after-tax dollars. The money grows completely tax-free. Withdrawals in retirement are also tax-free. Contributions (not earnings) can be withdrawn anytime penalty-free.
Anyone in a lower tax bracket now who expects to be in a higher bracket at retirement. Particularly powerful for younger earners.
Check current income eligibility limits on the IRS website (updated annually).
Open a Roth IRA at a reputable brokerage — many offer free accounts with no minimums.
Contribute up to the current annual limit. Consistent monthly contributions beat lump-sum if cash flow is tight.
Invest the contributions into index funds or target-date funds inside the account — don't leave them in cash.