How to file a claim. If you do need to file a Medicare claim, you will have to complete a “Patient’s Request for Medical Payment” form and send the completed form, along with an itemized bill from your provider, to the Medicare contractor for your state.To look up your state’s Medicare contractor, visit CMS.gov or contact Medicare.hen you need to file a Medicare claim. In rare cases, you may have to file a claim for reimbursement. This may happen if you received services from a provider that did not accept Medicare assignment.