Medicare and supplimental premiums on Schedule C

Yes, but only the premiums for the months that you were actively working as self-employed.  For example, if you worked as self-employed the months of February, March, and April, and then July, September, and November, then you can deduct six months of Medicare, Medicare Supplement, and Medicare Part D premiums.  

So if I was activly working on the project Jan-July, I can only claim 7 months of medicare premiums not the entire year? Is that correct?

Yes, that is correct. And you can't write off more in health insurance premiums than you earned.

@booshebach1