The new studies find the uninsured include so-called "young invincibles," those 18 to 34, Latinos and seasonal workers.
Last year, some people faced delays to see if they qualified for government insurance.
Customers can enroll online, by phone or at 2,700 of Wal-Mart's more than 4,000 stores, starting Oct. 10.
The Census Bureau also found nearly 63 percent of low-income Colorado children are covered by government health insurance programs.
Some plans will cost more, some less.
Four resort towns had some of the highest premiums in the country.
The Colorado Insurance Commissioner's plan to group resorts with other counties will have to go to White House.
New plan would eliminate a mountainous zone dubbed the "Resort" region and four mountain counties would join other rural areas in western Colorado.