A couple other things to consider: You can have both a traditional IRA and a Roth IRA, but your annual collective contributions cannot exceed $6,000 if you’re under 50. You can convert a traditional IRA into a Roth IRA at any time by paying the taxes owed. A combination of … TD Ameritrade Minimum Initial Investment Deposit To Open Account 2020 TD Ameritrade minimum investment to open brokerage account or ROTH IRA. TD Ameritrade minimum balance and initial deposit amount requirement. The Roth IRA offers retirement investors potentially tax-free retirement distributions. This article explains many features of the Roth IRA. Retirement-conscious investors have long recognized the benefits of the traditional IRA. Another alternative, available since 1998, is the Roth IRA.