If you qualify for a subsidy
Connect for Health Colorado is the most affordable coverage available, full stop. Medicaid is expanded (Health First Colorado) in Colorado.
If you don't
Full-price marketplace plans are the most expensive coverage in Colorado. For healthy people, private PPOs on Cigna, Aetna and PHCS PPO are routinely 30–50% less. Colorado has no state individual mandate.
What's not affordable
Health-sharing ministries and indemnity plans look cheap until you have a claim. Ask for the out-of-pocket maximum; if there isn't one, it isn't insurance.
Colorado requires carriers to sell standardized 'Colorado Option' plans on the marketplace, and mountain-county premiums run well above Front Range prices — the gap private plans tend to close.