C.R.S. § 10-16-427

(1) Every contract between a health maintenance organization and a medical group, independent practice association, or health professional employed by a health maintenance organization shall be written and include a hold harmless provision which shall provide that in the event a health maintenance organization fails to pay for health-care services rendered to an enrollee pursuant to a written contract between the health maintenance organization and a medical group, independent practice association, or health professional employed by the health maintenance organization, the enrollee shall not be liable for any moneys owed by the health maintenance organization. (2) No medical group, independent practice association, or health professional employed by a health maintenance organization referred to in subsection (1) of this section or any agent, trustee, or contractee thereof may maintain any action against an enrollee for sums owed by the health maintenance organization.