John Goodman writes for the Independent Institute about the need for additional reforms that affect health care’s supply side.

This year will be the last in which uninsured Americans are forced to pay ObamaCare’s penalty for lack of coverage. The change—part of the GOP’s tax reform—comes as relief on the demand side of health insurance. Yet nothing has changed on the market’s supply side. Without additional reforms to ObamaCare’s restrictions on insurers, millions of Americans will continue to choose from a limited range of lackluster plans.

Many of the country’s top hospitals are off limits to patients covered by ObamaCare’s current plans. Take Houston’s MD Anderson Cancer Center, which was named America’s best cancer-care hospital by U.S. News & World Report in 13 of the past 16 years. The hospital’s website suggests that it takes even garden-variety Medicaid, but it doesn’t accept a single private health-insurance plan sold on the individual market in Texas.

Since Blue Cross of Minnesota withdrew from the individual market in 2016, the state’s Mayo Clinic—once cited by President Obama as a model for the nation—has been off limits to Minnesotans covered by ObamaCare exchange plans. Memorial Sloan Kettering appears out of bounds for every exchange plan in New York. Both of these hospitals are open to some Medicaid patients, though Mayo’s chief executive has predicted publicly that Medicaid patients may eventually have to queue behind their privately insured peers.

Think about these developments. When Mr. Obama promised to insure the uninsured, what kind of insurance was he talking about? Most people, and maybe even the president himself, imagined it would look like a typical employer plan or a standard Blue Cross individual policy. Who imagined that the only products available would be more limited than Medicaid?