If you decide at any point in the future that you want to change or cancel your AIP, you simply need to call TD Ameritrade and request a change. With a broker, you should sign up for the DRIP dividend reinvestment plan , which will automatically reinvestment dividends for free too. But with retirement, budgeting is required today. And contributing regularly can help you accumulate assets faster. And, amazingly, it is absolutely free. Minimums for funds bought through an IRA are often different too.