The head of the Council for Affordable Health Insurance says most U.S. residents who have major medical insurance probably have enough coverage.

Merrill Matthews, executive director of CAHI, Alexandria, Va., has joined the dialogue about whether U.S. residents with health coverage are underinsured, overinsured or perfectly well insured.

Some families now have $10,000 deductibles either because of a voluntary decision to assume more risk or because that is the only kind of coverage they can afford, Matthews writes in a commentary on the topic.

But today U.S. families with extremely high out-of-pocket health care costs are still rare, Matthews writes.

A 2006 study backed by the Henry J. Kaiser Family Foundation, Menlo Park, Calif., found that only 1% of U.S. residents spent more than $4,331 on health care in 2003, and only 1% of non-elderly U.S. residents with health insurance spent more than $2,467, Matthews says.

“That can pinch the budget, but it hardly qualifies as an underinsured crisis,” Matthews writes. “The fact is that most Americans are ‘overinsured,’ not underinsured, because they have insurance to cover bills they could easily, if albeit reluctantly, pay for out of pocket.”

Matthews was responding to a study recently commissioned by the Commonwealth Fund, New York.

Cathy Schoen and the other health policy researchers who conducted that study estimated that the United States may be home to 16 million people who are underinsured as well as to 45 million without any health insurance.

Schoen and her colleagues define an “underinsured person” as an individual who has health insurance, but lacks adequate financial protection such as an individual with a policy that can allow out-of-pocket medical expenses to exceed 10% of annual household income.

Underinsured people often have the same trouble getting adequate medical care than uninsured people have, Schoen and her colleagues write in their study.