Coordination of Benefits Contractor roles and responsibility

The Coordination of Benefits Contractor (COBC) performs activities that support the collection, management, and reporting of other health insurance or coverage for Medicare beneficiaries. The COBC also has responsibility for consolidation of the claims crossover process, which ensures that payers, including State Medicaid Agencies, have

the opportunity to receive Medicare processed claims from one source for their use in calculating their supplemental payment. The COBC assists providers and suppliers with the following:

Answering general questions regarding MSP;

Verifying Medicare’s primary/secondary status (note that insurer-specific information will not be released; information on payers primary to Medicare must be requested from the beneficiary prior to billing);

Reporting changes to a beneficiary’s health insurance or coverage; and

Reporting a beneficiary’s accident/injury.


If a provider or supplier submits a claim for primary payment on behalf of a beneficiary and there is information either on the claim form or in Medicare’s system of records indicating that Medicare is properly the secondary payer, the claim will be denied unless the provider or supplier has submitted sufficient evidence to demonstrate that Medicare is properly the primary payer for the services provided. The beneficiary cannot be billed when a claim is denied because a primary payer to Medicare exists. If a provider or supplier submits a claim for secondary payment on behalf of a beneficiary but there is no information in Medicare’s system of records to identify the MSP situation and the claim form does not contain sufficient information to update Medicare’s system of records, the COBC will investigate in an effort to obtain the required information.


The COBC determines whether beneficiaries have health insurance that is primary to Medicare through the following mechanisms:

Initial enrollment questionnaire, which is sent to Medicare beneficiaries approximately three months before Medicare coverage begins regarding their other health insurance or coverage;

 Internal Revenue Service, Social Security Administration, and CMS data match, which are completed by employers regarding GHP coverage for identified workers who are either entitled to Medicare or are married to a Medicare beneficiary;

MSP claims investigation, which is a collection of data regarding health insurance or coverage that may be primary to Medicare based on information submitted on a medical claim or from other sources; and

Voluntary MSP data match agreements that allow for electronic data exchange of GHP eligibility and Medicare information between CMS and employers or insurers