Patients with Medicare coverage have a guaranteed right to appeal decisions about their health care coverage. You can appeal a denial of coverage of a medical service or a refusal to reimburse your medical costs. Regardless of which type of Medicare you are appealing (Part A, B, C, or D), the appeal process starts out with a request for your Plan provider or Medicare administrator to reconsider the initial decision. Next you can ask a specific outside review body to review your claim. If you are still denied, you can request a hearing with an administrative law judge at the Office of Medicare Hearings and Appeals.
Medicaid appeals are much different, since Medicaid is a state-run program.