Obamacare is bringing sweeping changes to the health insurance industry next year. With a number of reforms on the cusp of implementation, insurance's leading companies head into a murky future -- and shareholders still are left wondering how the brave new world of health care will affect their portfolios.

With all the question marks, however, at least one major insurance staple received some good news earlier this week. The Congressional Budget Office estimated that Medicare Advantage enrollees -- once thought to decrease in the near future -- will rise by 50% between today and 2023, a boon for major Medicare insurers looking to expand their enrollment numbers. What does this mean for your portfolio, and what stocks are best positioned to capitalize on the good news? Motley Fool contributor Dan Carroll and health care analyst Max Macaluso discuss what you need to know below.