Your number is bloated, it is in the 40 million and second you are talking about a snapshot of people uninsured (often in between jobs)
"43.6 million are said to be without health insurance. People often have short spells without health insurance, just as they have short spells being statistically poor or unemployed. Many of those without health insurance in November were different people than those without insurance when the March survey was taken.
To fix such problems, a superior Survey of Income and Program Participation (SIPP) is less frequent but more intense. That survey is conducted four times a year but not every year. In 1998, the latest available, the SIPP survey found
only 21 million without health insurance for the entire year — half the number in the headlines.
http://www.cato.org/research/articles/reynolds-031005.html
And remember, don't assume that people without insurance can't afford it.
As America gets wealthier and insurance becomes more expensive, many are simply freely choosing NOT to buy insurance and just pay for healthcare when needed.
You may think that risky, but that is their free choice and it's nice to live in a rare industrialized country with the FREEDOM to choose NOT to pay for insurance.