Industry News

CMS Releases MLN Matters on New Medicare Beneficiary Identifiers.

The Centers for Medicare & Medicaid Services (CMS) recently released a Medicare Learning Network (MLN) Matters article that outlines how providers can find and use a beneficiary’s new Medicare Beneficiary Identifier (MBI).  As of April 2019, a beneficiary MBI will replace the SSN-based Health Insurance Claim Number (HICN) on the patient’s Medicare Card, but a provider can use the HICN or MBI until December 31,2019.  However, after December 31, 2019 providers must use MBIs for all transactions, even where the corresponding date of service was prior to December 31, 2019, with exceptions for appeals, some claim status inquiries, and some span-date claims.

The MLN article details how Providers should use the MBI.  MBIs should be used for Medicare transactions such as billing, eligibility inquiries, and claims status checks.  Providers will use the MBI in the same way providers currently use HICNs and should enter the MBI into the same field on claims, inquiries, and other transactions.  A provider’s office can retrieve MBIs in three ways, either by asking the Medicare patient, using a Medicare Administrative Contractor’s secure MBI look-up tool, or checking the remittance advice.  Note that Medicare Advantage and Prescription Drug plans will continue to assign and use their own insurance cards and unique identifiers, and providers should still ask patients in these plans for their insurance cards.  However, providers can use the MBI look-up tool to obtain an MBI for patients enrolled in a Medicare Advantage Plan.

A beneficiary, the beneficiary’s authorized representative, or CMS may request an MBI change if, for example, the number is compromised.  If there is a change to a beneficiary’s MBI, a provider may have to use the old or new MBI, depending on the scenario.  Specifically, for Fee-For-Services (FFS) claims:

  • A provider can use the old or new MBI for claims with a date of service prior to the MBI change;
  • A provider can use the old or new MBI for span-date claims that start with a “from date” prior to the MBI change; and
  • A provider should use the new MBI for claims that have a date of service entirely on or after the new MBI effective date.

Additionally, if there is an MBI change, the use of an old or new MBI will affect the data received when a provider submits an FFS eligibility transaction inquiry as follows:

  • If a provider inquires using a new MBI, CMS will return all eligibility data;
  • If a provider inquires using an old MBI and a request date or date range that overlaps with the new and old MBI, CMS will return all eligibility data and the old MBI termination date; and
  • If a provider inquires using the old MBI and requests a date or date range on or after the new MBI’s effective date, CMS will return an error code.

CMS cautions that an MBI is personally identifiable information and should be treated as confidential information similar to the HICN.  Also, if a covered entity or business associate subject to the Health Insurance Portability and Accountability Act (HIPAA) holds an MBI, it should be treated as PHI.

Provider can find an educational tool on MBIs at:

The MLN matters can be found at: