“I know a lot about health care,” President Donald Trump declared in a Wednesday interview with the New York Times.

But Trump’s answers to other questions betrayed how little he knows about health policy. As Ezra Klein wrote yesterday, this has become a major stumbling block in Republican efforts to repeal and replace Obamacare. Trump can’t strike a deal on health care when he doesn’t understand health policy.

Trump cited numbers that don’t seem to come from any recent version of the health care debate.

“From the moment the insurance, you’re 21 years old, you start working and you’re paying $12 a year for insurance, and by the time you’re 70, you get a nice plan,” Trump told the Times.

Of course, anyone who has purchased health coverage, let alone studied the health insurance market, knows that a $12 annual premium is nonexistent — and that premiums are typically paid in months rather than years. The numbers Trump cites seem to come from the universe of life insurance rather than that of health insurance. Life insurance premiums are significantly lower and a completely different benefit program than health coverage.

This isn’t the first time Trump has so dramatically underestimated the costs of health insurance. In a May interview with the Economist, he estimated that health coverage ought to cost $15 per month.

“Insurance is, you’re 20 years old, you just graduated from college, and you start paying $15 a month for the rest of your life and you really need it, you’re still paying the same amount and that’s really insurance,” Trump told the magazine.

The fact that Trump settles on $12 or $15 as the appropriate amount to pay for health insurance betrays a lack of familiarity with the actual cost of coverage. You do not have to be a health policy expert to get this — just someone who has ever purchased a health plan.

Most voters I talk to don’t have this expectation. I often ask Obamacare enrollees what they think would be a fair price for health insurance. Usually I hear something between $50 and $100 seems reasonable. The mental math going on here is that you have to pay something in order to get a plan that will cover doctor visits and hospital trips and prescription drugs. They know, from their experience, that health coverage is not as cheap as $15, and have more realistic assumptions than the one Trump makes in this answer.

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