The best way to fund your Roth individual retirement account (Roth IRA) is to invest the maximum amount permitted each year. It’s a bad idea to withdraw funds, incurring penalties and taxes, if you withdraw the earnings before age 59½ and before the funds have been in the account for five years. (Your contributions can be withdrawn at any time, penalty free.) This strategy allows you to benefit from compound interest—interest that is accrued on the interest previously earned. This results in higher earnings than simple interest.