The Trump administration’s move to expand the types of health plans on the Obamacare exchanges to those that don’t include built-in doctor networks clears the way for alternative insurance companies to enter the market, even as several operational questions remain unanswered.

The Centers for Medicare & Medicaid Services last month finalized a rule opening the exchanges in 2028 to non-network plans. The plans instead offer a fixed rate for medical care, and enrollees can theoretically see any doctor as long as they’ll pay any difference between the doctor’s charge and the plan’s payment.

The move underscores the Trump administration’s goal …