Slightly more than 20,000 people in Colorado will be affected by the decision of UnitedHealth and Humana to exit the individual market and the state’s health insurance exchange.

“It’s not too much a blow to the system,” said Vincent Plymell, communications manager for the Colorado Division of Insurance.

The exchange, Connect for Health Colorado, is the marketplace for consumers buying health insurance under the Affordable Care Act.

The decisions by the insurers will impact 10,549 people who use UnitedHealth and 9,914 people who use Humana, the division said in a news release. About 420,000 people bought their health insurance in the individual plan market in 2015, both on and off the exchange, according to a survey by the Colorado Health Institute.

For 2017, UnitedHealth, along with most of its subsidiaries, is discontinuing its participation in the individual market in Colorado, on and off the exchange. Golden Rule Insurance, a UnitedHealth subsidiary, will continue to offer its individual plans in Colorado off of the exchange. UnitedHealth still will offer small and large group business plans.

Humana will continue in the small group market for 2017 off the exchange, while exiting the individual market for Humana Health Plans and Humana Health Insurance Co.

Coverage for consumers with individual plans from these companies will remain in place until Dec. 31. Consumers should expect notices of cancellation in July.