special correspondent sarah varney begins our report in north carolina.story was produced in collaboration with kaiser health news. >> reporter: it's been a bitterly cold winter in the blue ridge mountains for julia ray and 13-year-old son charles. >> did you drink your coffee already? >> yes. >> reporter: but despite the punishing weather, 2015 is looking good. ray has finally been able to afford the insulin and other medications she needs to keep her diabetes under control. she's a self-employed auditor who relies on a $400 a month government subsidy to afford the private health plan she bought on mac.gov. before the affordable care act made tax credits available to low and moderate income workers, ray was uninsured. back then just one of her diabetes medications cost $320. >> during that time, i had no insurance, and i really just wasn't taking my medicine, and there were times when my sugars and things would get up to 600. i remember getting to a point where the ambulance had to take me in because i was pretty much in a diabetic shock kind of situatio