Massachusetts inputting health coverage for Medicare

I was on private health insurance from Jan to Sept. of 2020.  For the last 3 months of the year I switched over to a Medicare advantage plan administered by Anthem, because I turned 65 and became eligible.  How do I show Medicare coverage for those last 3 months on the turbotax health coverage screen for Massachusetts?  Medicare and it's associated advantage plans do not send 1099-HC forms, nor do they upon request.  Do I just input that I had coverage for the whole year with my private carrier??  I tried calling Medicare, Social Security and the Anthem advantage plan and got the same answer, that NO 1099-HC is sent.