From https://www.irs.gov/pub/irs-utl/...  (emphasis mine):DONE WITH THIS FORM — Select this button to save and close the form you are currently viewing and return to your 1040 form. This button is disabled when you are in your 1040 formSo, it appears, and without them mentioning it while you're working on it, that button is for all forms except 1040. Thank you to the other response to this question. I would never have thought of just clicking the Step 2 tab.