Is the "Roth Contributions prior to 2024" looking for the "cost basis" and to include 401k Rollovers since since I opened my Roth IRA 24 years ago?"
Yes, normally when TurboTax asks for your Roth IRA contributions prior to 2024, it is looking for your total cost basis—the sum of all your after-tax contributions made over the years, excluding any earnings or gains. This includes any pre-tax 401(k) rollovers that were taxed when they were converted to a Roth IRA.
TurboTax asks for this information to help determine the tax-free withdrawal amounts.