CMS identified a concerning trend of malicious actors stealing MBIs and using them to commit Medicare fraud. Some are misusing Medicare Administrative Contractor (MAC) MBI lookup tools. We’re implementing enhanced monitoring controls to prevent this abuse.

What You Need to Know

Only use the MAC MBI lookup tool for people you intend to provide a service or product to that you’ll bill to Medicare. Our enhanced monitoring compares the MBIs you look up against actual claims submitted with NPIs. If we notice an unusually high rate of MBI lookups without associated claims, your access to the lookup tool may be removed.

Make sure your MAC portal users are associated with NPIs in your organization on whose behalf they may perform MBI lookups. This helps us verify legitimate use and protects your access to the lookup tool.