Starting January 1, 2020, you MUST submit claims using MBIs regardless of the date the service was performed. Claims submitted without the MBI will be rejected and not processed by Medicare. MBIs replace the Social Security Number (SSN)-based Health Insurance Claim Numbers (HICNs). MBIs are 11-characters in length and are made up only of numbers and uppercase letters (no special characters).

All existing Medicare beneficiaries have received new cards with their MBI and all new beneficiaries are issued MBIs. The patient’s MBI also appears on every electronic remittance advice for claims submitted with a valid and active HICN during the transition period. You can also look up any Medicare patient’s MBI, regardless of where the patient lives using your Medicare Administrative Carrier’s (MAC) portal. You can use this tool even after the end of the transition period on December 31, 2019.

If you have not begun the process of transitioning to the new MBIs, now is the time to start. Given that ALL Medicare claims must report the MBI on January 1, 2020, you can save a lot of time and avoid reimbursement delays by making the changes now.

CMS has web resources specific to the MBI that includes general information, resources for providers and managers and outreach and education tools and information. It can be accessed here

Many MACs have also provided outreach and educational information and tools. You can find your MACs website here.