"Turbo Tax does not calculate the excess contribution correctly using the interview questions."
TurboTax calculates correctly. Given that you correctly indicated to TurboTax that you were HSA eligible for only January and that you were covered by Medicare the rest of the year, TurboTax will correctly indicate that you (and your employer on your behalf) are eligible to contribute a total of only 1/12 of the annual maximum that would apply if you were instead an eligible individual the entire year. Any amount contributed beyond that is an excess contribution includible in income and subject to penalty unless corrected by a return of excess contribution by the due date of your 2024 tax return, including extensions.
