Robert Arias explained why he thinks millennials are not signing up for Obamacare [“Why millennials pass on Obamacare,” letters, March 23]. One: They probably don’t need health insurance, and many can’t afford it. Two: If they do need it, they can sign up during the next open-enrollment season. Three: The tax penalties are too small to provide a real incentive to sign up. It seems simple.

But a lot can happen between steps one and two. What happens if the uninsured person, instead of developing “health problems,” has a sports injury, is in a car crash or contracts a life-threatening disease? While it is true that he or she can sign up during the next open enrollment period, who pays for treatment in the meantime? I don’t think the uninsured person would be content to let the broken bones remain unset or the cancer continue to develop while waiting for weeks or months.

Such an unfortunate person would go to the emergency room, and the rest of us would pay for the treatment.

John J. Landers, Bethesda