What gaps does Original Medicare leave me with?

Original Medicare, meaning Part A and Part B, is solid foundational coverage. But it was never designed to cover everything, and the gaps can add up fast.The biggest one is that there is no out-of-pocket maximum. With most private insurance, your costs stop at some point each year. Original Medicare has no such ceiling. A long hospital stay or a serious illness could leave you with tens of thousands of dollars in cost-sharing, which is your share of the bill after Medicare pays its portion.Specifically, Part A has a deductible each benefit period, not just once a year. Part B covers 80 percent of most outpatient services, leaving you responsible for the other 20 percent with no cap. That 20 percent on a major surgery or ongoing specialist care can be significant.Beyond cost-sharing, Original Medicare doesn't cover prescription drugs. You need a separate Part D plan for that. Routine dental cleanings, eyeglasses, and hearing aids are also not covered, which surprises many people.Most people address these gaps by adding either a Medigap plan, sometimes called Medicare Supplement, which helps cover the cost-sharing, or by switching to Medicare Advantage, which bundles coverage and typically adds extra benefits. Each approach has tradeoffs worth understanding before you choose.