When is the Colorado marketplace 2027 open enrollment?

Colorado runs its own marketplace, so these dates come from the Colorado marketplace rather than the federal marketplace. They replace a December 31 deadline announced earlier. After January 15 you need a qualifying life event for a Special Enrollment Period.

The Colorado marketplace dates for 2027 coverage

Date	What happens
October 20 to 27, 2026	Planned maintenance: website, application, customer service and accounts unavailable
November 1, 2026	Open enrollment starts; current customers are automatically re-enrolled
December 15, 2026	Last day to enroll or change plans for coverage starting January 1, 2027
December 16, 2026 to January 15, 2027	Enrollments start February 1, 2027
January 15, 2027	Open enrollment ends

How renewal works for 2027

The Colorado marketplace automatically re-enrolls current customers at the start of open enrollment. Letting it roll can be costly: the Colorado Division of Insurance approved final 2027 individual market rates on September 22, 2026, with an average increase of 10% statewide and 10.8% in rating area 3, which includes Adams County. Cigna is also leaving Colorado's individual medical market, so Cigna members must choose a new plan.

What changes the answer

A Special Enrollment Period lets you enroll outside these dates after events like losing other coverage, moving, marriage or a new baby. People who qualify for Health First Colorado (Medicaid) or Child Health Plan Plus (CHP+) can apply any time of year.

The enhanced federal premium tax credits expired, so more households pay more. Colorado Premium Assistance, a state program, helped more than 176,000 customers lower their premiums in 2026 and continues for 2027, according to the Colorado marketplace.

Who in Adams County this affects

Adams County has more people without health insurance than Colorado as a whole: 11.6% of residents, against 7.7% statewide, in Census estimates for 2020 to 2024. Brighton sits at 10.1%, Thornton at 9.9% and Commerce City at 7.4%. Many are self-employed, between jobs or early retirees waiting for Medicare, the households this window is built for.

Timing examples

Enroll on December 14, 2026 and coverage starts January 1, 2027. Enroll on December 20 and it starts February 1, leaving January uncovered unless your old plan continues. Try on January 20, 2027 and you need a qualifying life event, such as losing job-based coverage or a move into Colorado, to enroll at all.

What to do next

Before November 1, gather your expected 2027 income, your doctors and your prescriptions. Then compare plans instead of accepting the automatic renewal. We help Brighton and Adams County families compare the Colorado marketplace plans; Adams County is also one of 10 counties with new or expanded enrollment assistance this year.

Related questions

Sources

1. Colorado marketplace: State solutions to counter rising costs (July 31, 2026) Colorado marketplace
2. Colorado marketplace: Preparing for Plan Year 2027 Colorado marketplace
3. Colorado Division of Insurance: Final ACA health insurance premium increases for plan year 2027 (September 22, 2026) Colorado Division of Insurance
4. U.S. Census Bureau, American Community Survey 2020 to 2024 5-year estimates U.S. Census Bureau

Please note: Headwaters Health and Wealth is not affiliated with, endorsed by, or operating on behalf of the Colorado marketplace, CMS, the Health Insurance Marketplace, or any federal or state government agency. Plan availability, premiums and advance premium tax credits are set by the carriers and the Marketplace.Estimates only. Figures on this page use published plan-year values and the details you enter. They are not a quote, an offer of coverage, or a determination of eligibility. Your final premium and any tax credit are confirmed at enrollment with the carrier or the Colorado marketplace.