There are times when a Medicare Beneficiary Identifier (MBI) may change. People with Medicare or their authorized representatives can request an MBI change. CMS can also initiate a change to an MBI (for example, if the MBI is compromised). There are different scenarios for using the old or new MBIs: Fee-For Service (FFS) claims submissions with:
- Dates of service before the MBI change date – use the old or new MBI
- Span-date claims with a “From Date” before the MBI change date – use the old or new MBI
- Dates of service that are entirely on or after the effective date of the MBI change – use the new MBI
- FFS eligibility transactions when the inquiry:
- Uses new MBI – we will return all eligibility data
- Uses the old MBI and request date or date range overlap the active period for the old
- MBI – CMS will return all eligibility data and the old MBI termination date
- Uses the old MBI and request date or date range are entirely on or after the effective date of the new MBI – CMS will return an error code (AAA 72) of “invalid member ID”
When the MBI changes, CMS asks people with Medicare to share the new MBI with providers. You can also get the MBI from your Medicare Administrative Contractor’s secure MBI lookup tool.
