MEDICARE - MBI Numbers - As of April 2026
MEDICARE -- As of April 2026, 1.3 million Medicare beneficiaries are receiving new Medicare Beneficiary Identifier (MBI) numbers due to suspected data breaches. These new numbers became effective on April 14, 2026. Claims submitted with the old MBI for services on or after April 14, 2026, are being denied because the identifier is technically terminated. Are you seeing the "reason code 31605 or U5065, indicating an invalid or terminated MBI?" For dates of service entirely on or after April 14, 2026, the old MBI is no longer valid, requiring a resubmission with the updated identifier.