Medicare's website has information about Part B eligibility, coverage, and enrollment. You can also call Medicare's toll-free phone number, (800)-MEDICARE ([800] 633-4227). Part B's day-to-day operations, however, are handled by large private insurance companies called Medicare Part B "carriers." Different carriers handle Part B in different regions of the country. If you have a question or complaint about a particular decision regarding someone's Part B coverage, contact the carrier directly. You can find the name and contact information for their carrier in the upper right-hand corner of the Medicare Summary Notice explaining the decision, which the carrier will have mailed to the participant. Or you can get the contact information from the Medicare website.

Navigating the Medicare bureaucracy may sound daunting, but the benefits of understanding the system can help participants get the best care possible -- and save a significant amount of money.