WASHINGTON — The United States has a terribly dysfunctional health-care system, unique among the rich countries in the word in its waste and abuse of its citizens.

As a nation we spend about twice as much per person as other high-income countries, and yet we have 50 million people uninsured and have worse health outcomes. This is not a result of Medicare or the nearly half of health-care spending that is funded by government, but rather the private insurance companies that dominate the system, as well as pharmaceutical companies.

The 2010 Affordable Care Act did not provide the needed reforms that would bring us to parity with the rest of the high-income world. However, it will bring significant and noticeable improvements in the health-care coverage of many Americans.

Some of this will be done by reducing or eliminating some of the worst abuses committed by private insurance companies. For example, by 2014 most insurance companies will not be allowed to discriminate against people who have a pre-existing health problem. This is now in effect for children up to age 19.

Most insurance companies are also prohibited from placing limits on the amount that they pay for a patient’s illness over a lifetime; and the law raises and then eliminates such limits on annual spending. The law also makes it more difficult for insurance companies to cancel a customer’s insurance after they get sick.

There are other benefits that expand coverage for those who have insurance. Parents will be allowed to keep their children on their insurance policies up to age 26. There is some reduction of prescription drug costs for Medicare patients. And in 2014, most insurance companies will also be required to cover treatment for mental health and substance abuse.

There are some loopholes and of course implementation can still be changed by future legislation. But most of these improvements can be expected to happen if the law survives.

The law will also expand health insurance coverage to an estimated 60 percent of the uninsured. This relies on a mandate for employers as well as uninsured individuals to purchase health insurance, with subsidies for low-income people. The mandate for individuals has become controversial and is also subject to legal challenges now pending at the U.S. Supreme Court.

Ironically, the reform is being attacked as having gone too far in expanding the government’s role in the health insurance system. But the real problem is that it did not go far enough.

A simple expansion of Medicare to cover the non-elderly population would have achieved much more that the ACA in terms of eliminating abuses, covered all of the uninsured and avoided the controversy over forcing people to pay money to private insurance companies.

It would be affordable because it would eliminate the biggest source of waste — which comes from private insurers. The second biggest source of waste — the monopoly pricing pharmaceuticals — could also be drastically reduced to save hundreds of billions of dollars each year.

When Medicare and Medicaid were enacted it was widely believed that covering the elderly and the poor were just the first steps to providing the same single-payer insurance to everyone.

That it has not happened yet is a result of the corruption of our political system by powerful corporations — especially pharmaceutical and insurance companies — and a lack of political leadership.

The major media have also played a supporting role in this process of keeping what Americans want and need off the political agenda. But Medicare for everyone is the future, and hopefully the ACA will end up being a step in that direction.

• Weisbrot is the co-director of the Center for Economic and Policy Research.