Now that a key provision of the health care reform law—the individual mandate—has gone into effect, it's clear the grand hopes held by many of extending health care to tens of millions of previously uninsured is unlikely to be fulfilled in the way many people envisioned.

Not that the health care reform law, which President Barack Obama signed in 2010, was ever going to be a quick fix. Fundamentally, the law was focused on extending coverage via insurance rather than being an overhaul of the U.S. health care system.

But as individuals begin going to the insurance exchanges to buy coverage, they are finding out what employers have known for years — health insurance is not cheap.

Putting hypothetical numbers into the Kaiser Family Foundation's health insurance subsidy calculator shows just how much money people will have to pay for coverage. A 30-year-old earning $25,000 a year buying single coverage would have to pay $1,729 after a federal premium subsidy for a silver-level plan, which as the name indicates, is second-rate coverage compared with some group plans.

That figure may not sound like a large amount, but it equates to nearly 7% of the individual's annual income.

If the same individual earned $35,000 a year, he or she would to pay $2,877 a year for coverage, which equates to more than 8% of the individual's income.

Alternatively, people can pay a fine. The fine in 2014 is the greater of $95 per family member, or 1% of family income, but not to exceed the cost of a bronze-level plan.

The difference between the fine vs. the cost of coverage via an exchange may not sound like a lot to an employee with a good salary and full coverage through his or her employer, but it's a significant chunk of money for young people, who are often still laden with college tuition debt, to pay in the current economic climate. And, as everybody in the world of insurance knows, it's imperative that those young, infrequent users of health care services buy insurance if the system is to work.

Looking at those figures as the equivalent of a tax increase also shows the difficulties in successfully providing comprehensive health care coverage to U.S. residents. Even if the extra money coming out of their paychecks was classified as a tax, individuals in the United States would still pay less in tax than people in the United Kingdom, whose government-funded health system with its long waiting lists would be unacceptable to most insured individuals in the United States, and they would be paying much less than individuals in France, whose health care services are generally viewed as top-notch.

Health care funding in the United States is in the midst of a painful transition and the knock-on effect for key players in the system — insured employees, uninsured individuals and employers — will continue to play out.