Eighteen states and the District of Columbia have made the commitment to open state-based exchanges through which individuals and small businesses can purchase health insurance under the Affordable Care Act, Department of Health and Human Services Secretary Kathleen Sebelius said in a Dec. 17 blog entry.

Ten states filed "blueprint" applications to operate their own exchanges by the Dec. 14 deadline: California, Hawaii, Idaho, Minnesota, Mississippi, Nevada, New Mexico, Rhode Island, Vermont, and Utah, Sebelius said. During the week of Dec. 10 HHS announced it has given conditional approval for state-based exchanges in Colorado, Connecticut, the District of Columbia, Kentucky, Massachusetts, Maryland, New York, Oregon, and Washington. Conditional approval means HHS has determined those states and D.C. are likely to be ready for open enrollment, which begins Oct. 1, 2013. The policies purchased through the exchanges take effect in 2014.

Estimates for how many of the remaining 32 states will enter into state partnership exchanges with HHS and how many will end up with the federally-facilitated exchange vary. Health care consulting firm Avalere Health LLC estimates that 12 states will enter into the partnerships and 20 states will have federal exchanges.  The deadline for applying for a partnership exchange is Feb. 15, 2013.