To start with, a recent review of the academic literature on the subject finds a mixed bag, but with the strongest link between coverage and health outcomes in cases where health insurance coverage improves access to care.

That makes sense. Having health insurance makes less of a difference to people with higher incomes who can afford to pay for more of their medical care directly.

The difference between being insured versus uninsured appears to be marginal to the healthy person with an infrequent need for care—though going without health insurance can turn out to be a bad bet if a major illness or accident strikes.

That leads us to the crucial, practical question: Who are the people that would no longer have health insurance if the mandate penalty were repealed?

Setting aside for the moment the—entirely separate—debate over the accuracy of CBO’s specific numbers, the agency projects that eliminating the mandate penalty will result in roughly 13 million fewer Americans having coverage by 2027. Of that number, CBO estimates that 5 million fewer people will be enrolled in individual market coverage; 5 million fewer in Medicaid; and more than 2 million fewer in employer group coverage.

Read the full article on the Affordable Care Act's individual mandate by Robert E. Moffit and Edmund F. Haislmaier at The Heritage Foundation