What to do when an MBI changes

Last week, I posted about the need to begin using Medicare Beneficiary Identifiers (MBIs) when billing Medicare. But what happens if a patient’s MBI changes (say, for example, the patient requests a new one because the old one was compromised by identity theft)?

The first hint your patient’s MBI may have changed is error code “AAA 72” (“invalid member ID”) on an eligibility transaction. In that situation, you can do a historic eligibility search to find out when the old MBI was terminated and get the new one from your Medicare Administrative Contractor’s secure MBI look-up tool.

If you do a fee-for-service (FFS) eligibility inquiry using the new MBI, Medicare will return all eligibility data. If you do the inquiry using the old MBI and the request date or date range overlaps the active period for the old MBI, Medicare will also return all eligibility data and the old MBI termination date. However, if you do the inquiry using the old MBI and the request date or date range is entirely on or after the effective date of the new MBI, Medicare will return error code "AAA 72" of “invalid member ID.”

FFS claims with dates of service before the MBI change date can be submitted using either the old or new MBI. Likewise, for claims with dates of service that span the MBI change date (the “From” date is before the MBI change and the “To” date is after it), you can also use either the old or new MBI. However, dates of service that are entirely on or after the effective date of the MBI change require you to use the new MBI.

— Kent Moore, Senior Strategist for Physician Payment at the American Academy of Family Physicians