What if I choose the wrong Medicare plan and then get very sick?

Nobody picks a Medicare plan expecting to get a cancer diagnosis or need a major surgery. But serious illness has a way of revealing exactly where a plan falls short, whether that's a drug not covered on the formulary, a specialist who's out of network, or an out-of-pocket maximum that's higher than you expected.Here's what's important to know. You are not locked into a plan forever. Medicare's Open Enrollment Period runs from October 15 to December 7 each year, and whatever you choose takes effect January 1. There's also a shorter window, January 1 through March 31, specifically for Medicare Advantage enrollees to make one plan change. These windows exist precisely because circumstances change.What you can't do is switch plans any time you want throughout the year without a qualifying reason. So if you get a difficult diagnosis in June, you may be managing with your current plan for several months before you can switch. That's the real cost of a mismatch.The best protection is a careful enrollment conversation before you sign up. That means looking at the drugs you already take, the doctors you want to keep, and what your plan's maximum out-of-pocket cost would be if something serious happened. A licensed agent can walk through that with you at no cost to you.Plan details change every year, so even if you reviewed everything carefully last year, it's worth checking again each fall.