First, close TurboTax, clear your Cache and Cookies and return to Deductions & Credits. Scroll down to Medical, click the down arrow, and Revisit the 1095-A interview. Be sure you indicate No, you did not have a 1095-A.
Or, in the left-side menu, click on Tools > Tax Tools, then choose Delete A Form from the pop-up menu. A list of forms in your return will be displayed, so you can scroll down to Form 1095-A and delete it.