The due date for Medicare premium payment depends on the type of Medicare coverage you have. For most people, the payment is due on the 25th of each month. However, if you are enrolled in a Medicare Advantage plan or a Medicare Prescription Drug Plan, the due date may vary. It's important to check with your specific plan to determine the exact due date for your premium payment. Additionally, it's worth noting that late payments may result in a lapse in coverage, so it's important to make sure your payment is submitted on time.