How fragile is the US healthcare system?

Millions of Americans are facing a huge increase in the amount they have to pay for health insurance. A dispute about government subsides for healthcare was one of the major issues that led to a 43-day shutdown of the U-S government last year- the longest in history. But even when the shutdown ended, Republicans and Democrats failed to agree on and extension of the the subsidies. As the clock struck midnight on January 1st - the health costs for 24 million people rose dramatically So, what's the impact for those in need? And how much politics is involved?