While it's true that investments held in a retirement account have no capital cost basis, an individual Roth IRAs have basis in contributions and Roth conversions. Basis in contributions and conversions is used on Form 8606 Part III when calculating the taxable amount of any nonqualified distribution from any of the individual's Roth IRAs.
"You may want to keep track of your contributions because if you take a distribution before you had the account open for five-years, you must pay the penalty for early withdrawal (but no tax on your contributions)."
That's rather inaccurate. Roth IRA distributions are subject to ordering rules that have contribution basis coming out first tax and penalty free no matter how long one has had a Roth IRA and any distribution made after age 59½ is not subject to penalty.
