How does stacking UM/UIM coverage work in Colorado?

Stacking allows you to combine UM/UIM coverage limits from multiple separate policies for greater protection. In Colorado, if you have two vehicles insured under separate policies, each with $100,000 in UIM coverage, stacking lets you access up to $200,000 in coverage for a single accident. The key requirement is that you must pay separate premiums on each policy. If you have multiple vehicles on a single policy, you cannot stack the UIM coverage. Colorado law prohibits insurers from including "anti-stacking" clauses in policies issued or renewed after January 1, 2008, so if you do maintain separate policies with separate premiums, you're entitled to stack those limits. Stacking can significantly increase your available coverage when you're seriously injured by an uninsured or underinsured driver.