What is the most common mistake people make when first getting Medicare?

Most people assume Medicare enrollment is automatic. Sometimes Part A is, but Part B almost never is, and the rules depend on your specific situation. If you're not receiving Social Security benefits when you turn 65, you have to actively sign up. Miss the window, and you could face a late enrollment penalty on your Part B premium that follows you for life.The Initial Enrollment Period is a seven-month window: three months before your 65th birthday month, your birthday month itself, and three months after. People often think they have until they actually need care to enroll. That's not how it works.The second most common mistake is assuming that staying on an employer plan protects you from penalties. It often does, but only if that employer coverage qualifies under Medicare's rules. Coverage through a small employer or COBRA does not count as qualifying coverage. Many people are surprised to learn this after the fact.A third mistake is skipping Part D (prescription drug coverage) because you don't take any medications right now. If you go without creditable drug coverage and later want to enroll, you'll face a late penalty added to your premium every month going forward.The good news is that these mistakes are avoidable with a little planning. Talk to someone who knows Medicare before you turn 65, not after.