Starting Jan. 1, 2020, CMS will reject any Medicare claims submitted with the SSN- based ID number for the beneficiary. A simple way to prevent claims denials is to make sure all your patients have their new card. Which is Medicare beneficiary identification. MBIs Required in 2020 The MBI phase-in period is complete, and all claims are expected to identify the beneficiary using their MBI. If the MBI is not used on claims after Jan. 1, the claim will be denied with one of the following reason codes: Electronic claims reject codes : Claims Status Category Code of A7 (acknowledgment rejected for invalid information), a Claims Status Code of 164 (entity’s contract/member number), and an Entity Code of IL (subscriber) Paper claims notices: Claim Adjustment Reason Code (CARC) 16 “Claim/service lacks information or has submission/billing error(s)” and Remittance Advice Remark Code (RARC) N382 “Missing/incomplete/invalid patient identifier” CMS says, to date, 87% of claims are submitted with