What do Medicare Beneficiary Identifiers (MBIs) mean for States?

If you’re a State Medicaid Agency in any state, the District of Columbia, or a U.S. territory, you need to be using Medicare Beneficiary Identifiers (MBIs) for your beneficiaries who are dually eligible for both Medicare and Medicaid.

When did states need to be ready for MBIs?

All of your systems are able to accept and are using the Health Insurance Claim Number (HICN) and/or MBI for beneficiaries who are dually eligible.

There's a transition period where providers, plans, beneficiaries, and other partners can use either the HICN or the MBI to exchange data with us. The transition period started on April 1, 2018 and will run through December 31, 2019.

After the transition period, providers, plans, beneficiaries, and other partners must use the dually eligible beneficiaries’ MBIs with us. Medicaid providers have to use MBIs in all transactions and all communications about dually eligible beneficiaries starting on January 1, 2020 (with very few exceptions). 

During the transition period, we're processing and transmitting Medicare crossover claims to State Medicaid Agencies and other COB payers with either the HICN or MBI. For crossover claims processing, during and even after the transition period, we'll keep sending you plan membership IDs or state Medicaid recipient IDs, like we always have.

For those that rely on the Medicare identifier instead of the State Medicaid ID, we'll keep providing both the HICN and MBI to State Medicaid Agencies and other COB payers through COBA eligibility response files, unless the beneficiary only ever had an MBI. In that case, we'll only provide the MBI.    

What do MBIs mean for other state entities & state partners?

If you work with beneficiaries who are dually eligible, providers, and/or health plans, you should have updated anything with the HICN, such as ID cards, beneficiary letters, training materials, or call center scripts with the MBI.

Where can states get more information about MBIs?

Read our frequently asked questions (PDF).

You can also check our Outreach & education page to get information for you and resources you can use when you talk to people with Medicare who don't have an MBI.





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Page Last Modified:
11/13/2019 06:31 PM