Your impression would have been correct, if you had had the HDHP coverage last year. If the HSA bank won't recharacterize the contribution to 2019, then you can do the following: (1) tell TurboTax that you will withdraw the entire excess (in your case, everything you contributed) before the return due date (April 15, 2019), (2) call the HSA bank and request a "withdrawal of excess contributions" (use that exact phrase so they'll do the paperwork right), and (3) when the check shows up (the withdrawn amount is mailed to you), contribute it to the HSA in 2019 and take the deduction in 2020 on the 2019 return. The only problem would be if what you contributed for 2018 plus what you have already contributed for 2019 is more than the annual HSA limit for 2019, well, you'll have to be careful not to exceed the limit. One year of excess contributions is enough. 😉
