The Americans who are least likely to have health coverage are the cheapest Americans to cover.[@@]

Researchers at eHealthInsurance Services Inc., Sunnyvale, Calif., have painted that picture in numbers in their latest individual and family health insurance cost survey report.

The researchers at eHealthInsurance, a Web-based health coverage broker, based their study on analysis of 80,000 health insurance policy sales made through the company’s Web site. The report includes a section on short-term medical insurance as well as a section on ordinary health coverage.

Although people ages 18 to 34 make up only 23% of the U.S. population, they make up 31% of the uninsured U.S. population, according to the eHealthInsurance researchers.

The likelihood that “young invincibles” will be uninsured is far higher than the likelihood for any other age group.

But eHealthInsurance researchers port that people ages 18 to 24 who actually buy health coverage through its site end up paying an average of just $109 for coverage. People ages 25 to 34 who buy through the site pay an average of $130 per month.

Averages for older customers range from $173 per month for customers ages 35 to 44 to $300 per month for customers ages 55 to 64.

Customers ages 18 to 34 who buy short-term medical plans, which usually exclude coverage for preventive care and routine maternity care, pay an average of less than $70 per month when they buy through the eHealthInsurance site.

“Overall, 41% of individuals pay $100 or less on monthly premiums,” the eHealthInsurance researchers write.