While Congress and President Trump fruitlessly debate how much the government should subsidize certain health insurance premiums, they are missing a far more important question: How could the US rationalize our eight (at least) completely separate health insurance systems?

This maze-like complexity comes at a price. Dividing Americans into multiple risk pools increases health care costs. It means patients lose access to trusted providers. And it seems impossible to have an honest debate about a health insurance system that almost nobody understands.

Most other developed countries avoid this chaos. Some rely on government-run, single-payer systems while others use regulated private insurers. And we could have a healthy argument about which is best.

But over the past 80 years, the US has patched together a crazy quilt of public and private insurance, with separate coverage for different groups. If you are keeping score, we have:

Employer sponsored insurance: This tax-favored system accidentally became the default insurance program during World War II. Today, it covers about 165 million Americans, making it by far the largest form of health insurance. It may be offered as managed care or through relatively open provider networks, though quality varies widely by employer.

The Affordable Care Act: The 2010 law covers about 24 million people who don’t have employer-based or government coverage. The ACA has three separate plans and multiple levels of income-based subsidies (perhaps you heard about them in recent weeks).

Medicaid and CHIP: For very low-income people, Medicaid and its related children’s health insurance program covers about 77 million. Each state sets its own rules within a broad federal framework. Most care is provided through private managed care organizations, usually insurance companies. Unlike other health insurance, Medicaid also covers long-term services and supports. 

Medicare: It covers about 70 million older adults and younger people with disabilities. And it really is two entirely separate systems. Original fee-for-service Medicare covers a bit less than half of enrollees while the majority now are in Medicare Advantage managed care. 

Original Medicare is divided into Part A hospital insurance; Part B that covers doctors, some nursing care, many tests, and certain medications; Part D for most other medications; and 10 separate Medicare Supplement (or Medigap) plans for extra insurance.

Medicare Advantage wraps Parts B and D into a single plan but restricts out-of-network access to providers.

Medicare Plus Medicaid: This twin coverage is for people of any age who are both poor and living with serious disabilities. About 12 million “dual eligibles,” receive both medical care and long-term supports and services.

Federal employee insurance: Federal civilian workers, including members of Congress and their staffs, have their own separate insurance provided by commercial carriers.

Tri-Care: Comprehensive health insurance for active-duty military, retirees, and their families. There are 16 different plans that generally rely on provider networks, though out-of-network care is allowed, often with higher out-of-pocket costs. While most care is free for those on active-duty, retirees may have co-pays and deductibles.

Veterans’ Health Care: The Veterans Administration offers its own comprehensive health coverage for qualified vets. Unlike Tri-Care, it generally provides medical care through its own physicians and hospitals though patients sometimes can use non-VA providers. Care for service-related conditions is free, while other care requires co-pays based on income. The VA can bill private insurance, including Medigap plans, for those out-of-pocket costs.

Ad Hoc subsidies. This isn’t really insurance at all. But patients have many ways to get medical care at discounted or even no cost. For instance, federal law requires hospitals to stabilize the medical condition of anyone who comes into their emergency departments, even if they have no insurance. Drug companies offer discount programs. And providers often care for patients that have high-deductible health plans but can’t pay their out-of-pocket costs.

This fragmented system makes insurance needlessly complicated and costly. Insurance is most efficient when it can spread risk among very large groups of people such as, say, an entire country. But in the US, we have split the country into multiple, small risk pools.

Older adults on Medicare pay more because they are more likely to be sick and can’t share the risk with younger, healthier people. Employees of small companies pay more for each dollar of insurance than workers at mega-firms that can spread the risk among many more employees.

And care can be a nightmare for those who move from program to program. Imagine a 60-something who has employer-based insurance, loses her job and goes on Medicaid, then turns 65 and shifts to Medicare. Three different systems. New doctors with each.

There Are Alternatives

We can do better. Depending on your political taste, there are many ways to go. Here are four:

There is Medicare for All, promoted by Sen Bernie Sanders (I-VT) and others. Essentially it would be soup-to-nuts coverage for everyone, based on the generous original Medicare model.

Health economists Amy Finkelstein and Liran Einav have proposed free, universal, basic health insurance for all. Finkelstein and Nirav are agnostic about whether the coverage would be provided by government, private insurers, or some combination.

In contrast with Sanders, their first-dollar coverage would be modest. However, people would have the option to buy more comprehensive supplemental insurance, something like Medigap.

Models like this already exist. For example, Switzerland provides universal coverage through private non-profit insurers. Everyone gets the same basic coverage with no medical underwriting.

Consumers can choose high-deductible plans with lower premiums or low-deductible plans with higher premiums. After the deductible, they pay 10% co-insurance up to a cap as well as an additional modest fee for hospital stays.

Five decades ago, conservative economist Martin Feldstein proposed universal coverage built on income-based copayments that would have replaced all coverage except for Medicare. Thirty years ago, he and MIT economist Jon Gruber refined the plan.

A more coherent, less fragmented insurance system won’t solve all of the US health care problems. And none of these models is perfect. But they all share two critical benefits: They provide consistent universal coverage across the population and are relatively easy to understand. And that matters.