Over three-fourths of providers now use the new patient numbers. Time is running out for you to get on board with the new Medicare Beneficiary Identifier. Starting Jan. 1, “we will reject claims you submit with the Health Insurance Claim Number (HICN) … and reject all eligibility transactions,” the Centers for Medicare & Medicaid Services warns in a recent message to providers The lion’s share of your peers are likely already on board. For the week ending Aug. 2, providers submitted 77 percent of fee-for-service claims with the MBI, CMS reveals. Two easy ways to obtain patients’ MBIs are your Medicare Administrative Contractor portal and looking on your remittance advices. “We return the MBI on the remittance advice for every claim with a valid and active HICN,” CMS says.