How universal healthcare work in practice? Actually, lots of different ways.

Latest report by the nonpartisan Commonwealth Fund (Mirror, Mirror 2017: International Comparison Reflects Flaws and Opportunities for Better U.S. Health Care), compares health care performance among advanced nations. 

America is at the bottom; 

The top three performers are Britain, Australia, and the Netherlands. 
These three leaders have very different systems.

Britain has true socialized medicine: The government provides health care directly through the National Health Service. 
Australia has a single-payer system, basically Medicare for All. 
But the Dutch have what we might call Obamacare done correctly: individuals are required to buy coverage from regulated private insurers, with subsidies to help them afford the premiums.

And the Dutch system works, which suggests that a lot could be accomplished via incremental improvements in the A.C.A.

Obamacare works in states that try to make it work