Colorado Revised Statutes Title 10. Insurance § 10-16-408. Open enrollment

(1) After a health maintenance organization has been in operation twenty-four months, it shall have an annual open enrollment period of at least one month during which it accepts enrollees up to the limits of its capacity, as determined by the health maintenance organization, in the order in which they apply for enrollment. A health maintenance organization may apply to the commissioner for authorization to impose such underwriting restrictions upon enrollment as are necessary to preserve its financial stability, to prevent excessive adverse selection by prospective enrollees, or to avoid unreasonably high or unmarketable charges for enrollee coverage for health-care services. The commissioner shall approve or deny such application within thirty days of the receipt thereof from the health maintenance organization.

(2) Health maintenance organizations providing or arranging for services exclusively on a group contract basis may limit the open enrollment provided for in subsection (1) of this section to all members of the group or groups covered by such contracts.

(3) Except as provided in subsection (2) of this section, the enrollment policies of health maintenance organizations may not be such as to prevent or hinder the enrollment by, or in any other manner discriminate against, persons eligible for medical benefits under Titles XVIII and XIX of the federal “Social Security Act” as authorized under Public Law 89-97;  such policies shall be grounds for suspension or revocation of the organization's certificate of authority issued pursuant to this article.