You call your doctor’s office before choosing Medicare coverage and ask what seems like a straightforward question: “Do you take Medicare?” The receptionist says yes, so you enroll in a Medicare Advantage plan and assume you’ll be able to keep seeing the same physician next year. Unfortunately, accepting Medicare and participating in a specific Medicare Advantage provider network aren’t necessarily the same thing. Medicare Advantage plans are offered by private insurance companies, and many establish their own networks of doctors, specialists, hospitals, and other healthcare providers. Before choosing 2027 coverage, Medicare beneficiaries who care about keeping particular doctors need to ask a much more specific question.