Do retirees really need supplemental coverage with Original Medicare?

Original Medicare provides valuable coverage, but it also comes with coverage gaps that can expose retirees to financial risk. A_Carina/Getty Images

For millions of retirees, turning 65 and enrolling in Medicare can feel like crossing the finish line after decades of paying into the system. But what many are surprised to discover after enrolling is that Original Medicare — which includes Parts A and B — doesn't cover everything . Hospital stays, doctor visits, and certain preventive services are included, but things like deductibles, copays and other uncovered services can quickly add up. Medicare is designed to cover about 80% of medical costs on average, after all, which leaves beneficiaries responsible for the rest.

Those out-of-pocket expenses can be manageable for some r