Your local Medicare carrier has a directory that lists all doctors and suppliers in your area who always take assignment. If you want to limit the amount you pay for medical expenses, it is a good idea to obtain a copy of this directory and use it when choosing your health care providers. The limit is 15 percent above Medicare's approved charge. Some states, including Massachusetts, Minnesota, Rhode Island, Pennsylvania, Ohio, Connecticut, Vermont and New York, have stricter limits. But federal law prohibits doctors from charging Medicare patients more than 15 percent above the Medicare-approved charge.
Some states have even stricter limits.
Medicare will pay you 80 percent of its approved charge, and you will be responsible for the rest of the doctor's bill up to the applicable federal or state limit. Hospitals cannot refuse patients on the ground that their health coverage is through Part A of Medicare. Remember, though, not all hospital stays or services are covered by Medicare. It is the hospital's responsibility to inform you if something is not covered. Medicare is the primary payer if your employer has less than 20 employees.