Medicare open enrollment runs from Oct. 15 to Dec. 7. During this period, Medicare enrollees 65 and older can switch plans. Options include traditional Medicare and Medicare Advantage.

Unlike Medicare provided by the government, Advantage plans are private insurance. Forty-two percent of beneficiaries today have the Advantage program. What is the reason? They often have lower premiums and additional benefits. There are currently 33 plans to choose from.

But let the buyer beware: they could cost more in the end. Most qualified individuals will get multiple fliers in the mail and increasing robo...