No, TurboTax will save the personal information you entered last year. You had his personal details entered but he was not listed as a dependent because he didn't qualify to be your dependent (he provided over half his own support). So, TurboTax did not claim him, but the software will kept his details (name, SSN, birthdate) when transferring in a previous year's return at the beginning of preparing a new return. It won't save any answers to the dependent questions - it will ask you all of the questions again this year, so if for some reason he doesn't qualify again, TurboTax will again not claim him but will save his personal as long as you don't delete the worksheet. You do not have to delete the personal info worksheet when you are not claiming a dependent (using the desktop software). As long as you confirmed he was not listed on your 2020 return, TurboTax did what it was supposed to do in this situation (save you some data entry :).