Although the IRS can know from the Forms 5498 filed by your Roth IRA custodian the amount of your contributions, it's your responsibility to tack those for inclusion on Form 8606. If you have been using TurboTax over the years, you should have been entering your Roth IRA contributions so that TurboTax can track those for you. Otherwise, you'll need to tell 2024 TurboTax the amount of your contributions made for years prior to 2024 and separately enter any contributions that you made for 2024 so that TurboTax will have the information needed to prepare Form 8606 Part III.
