Question: What will happen if I submit a claim for a Medicare beneficiary that uses their 2019 Health Insurance Claim Number (HICN) instead of the new Medicare Beneficiary Identifier (MBI)? Minnesota Subscriber Answer: Beginning Jan. 1, 2020, Medicare will reject claims and eligibility transactions submitted with HICNs. However, there are a few exceptions. The Centers for Medicare & Medicaid Services (CMS) and the Medicare Learning Network note that you can still use HICNs (or MBIs) for certain appeals and their related forms, and you can use HICNs (or MBIs) to check the status of a claim if the earliest date of service on the claim is before Jan. 1, 2020. Note: If you are checking the status of a claim with a date of service on or after Jan. 1, 2020, you must use the MBI instead, CMS says.