I can't see where I do the selection 'auto-calculate medicare premiums'.
@karenarmingtongmail-com You just click in the yellow cell label "Auto-Calculate Medicare Premiums" on the Expenses > Healthcare page. That action will insert a checkmark in that cell and the tool will then start generating the Medicare premiums for you.
Stuart
@karenarmingtongmail-com Your screenshot cuts off a little too quickly on the bottom for me to see that cell completely, but it's the yellow cell just beneath Period 5 Out of Pocket expenses. The cell that should contain the "Auto-Calculate Medicare Premiums" label (just beath "Period 5: Both of you are eligible...") appears to contain some other unexpected value (maybe a "1"?) for some reason, so your file may have become corrupted. But the yellow box is where you need the checkmark.
Stuart