Colorado recently passed a major landmark, topping 1 million people enrolled in Medicaid.
Researchers attribute the drop to the state's embracing of the Affordable Care Act.
"If you receive tax credits to help lower the cost of your health insurance, there is no reason for concern about your coverage," a state official said.
The Colorado Insurance Commissioner's plan to group resorts with other counties will have to go to White House.
The cost to set up Connect for Health was paid almost entirely by federal grants. Those grants run out next year.
Rising premiums are forcing Colorado companies to choose between group plans or ask employees to buy individual coverage through Connect for Health Colorado.
Officials say more than 250,000 signed up for health insurance or Medicaid before the March 31 deadline for open enrollment.
March 31 is the deadline to sign up for private insurance through Colorado's health exchange but the state says it will give applicants a little extra time.