Why Doesn’t Income Below the Poverty Level Qualify for Premium Tax Credits?

I have been found by Social Security as disabled since 2014 and in 2016 was in a very bad car accident which increased my disability. Why can’t I get full Medicaid just on that? I have to see 4 Specialist numerous times each year and am in the hospital or a rehabilitation center a minimum of 3 – 15 days each time. I make below the FPL and can on get “Share of Cost” with Medicaid in Florida. Had they expanded Medicaid in 2017, I would not be under large medical bills which the ambulance company will not accept $20 payments as their minimum acceptable payment is $25.00. Said they cannot guarantee that I won’t be sent to collects if only paying them a lower amount! Yes, they are all fine and well selling your account to a collection agency getting maybe 60 cents on the dollar but I can’t get help thru medicaid because I make less than those who they’ll help??!! God help us all when those who desperately need financial help can’t get it because they need it.