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Coordination of Benefits Agreement

In-Use COBA Claim File Formats

The current in-use production claim file formats under the COBA program, in accordance with the transaction & code sets  adopted by the Secretary of Health & Human Services through a final rule published in 45 CFR 162 during 2003 and within the Federal Register February 20, 2003, are as follows:

  • American National Standards Institute (ANSI) Accredited Standards Committee (ASC) X12N 837 version 4010A1 institutional claim
  • ANSI ASC X12N 837 version 4010A1 professional claim
  • National Council for Prescription Drugs (NCPDP) Version 5.1, Batch Standard 1.1

A transcript of the June 9, 2009 and the June 23, 2009 presentation (Medicaid) of the 5010 and NCPDP COB testing call is available in the download section located near the bottom of this page

The Coordination of Benefits Agreement (COBA) Program establishes a nationally standard contract between CMS and other health insurance organizations that defines the criteria for transmitting enrollee eligibility data and Medicare adjudicated claim data.  In 2006, the CMS fully transferred the claims crossover functions from individual Medicare fee-for-service contractors to a national claims crossover contractor, the Coordination of Benefits Contractor (COBC). This consolidation allows for the establishment of unique identifiers (COBA IDs) to be associated with each contract and payer line of business and creates a national repository for COBA information.

How the Coordination of Benefits Agreements Works

  • Trading partners generate an eligibility file to the COBC using the COBA Eligibility (E-01) Record Layout format that is documented on the Eligibility File Format page.  For those beneficiaries listed on the eligibility file the COBC will transfer claims to trading partners in the HIPAA ANSI-X12N 837 COB (version 4010-A1) and National Council for Prescription Drug Programs (NCPDP) version 5.1 batch standard 1.1 formats.
  • Trading partners that provide drug coverage that pays supplemental to Medicare Part D coverage have the option of reporting this eligibility data to CMS via the COBA E-02 Eligibility File.  The Drug Coverage Record layout may also be downloaded from the Eligibility File Format page.

Enroll in the COBA Program

  • To get started in learning about COBA, simply click on the links at the bottom on the page and under “Overview” at the top left.    

For additional information about the COBA program, e-mail us at COBVA@EHMEDICARE.COM or contact the COBC at 1-800-999-1118 or TTY/TDD 1-800-318-8782 for the hearing and speech impaired, Monday through Friday, from 9:00 a.m. - 5:00 p.m., Eastern Standard Time, except holidays.

Health Insurance Portability and Accountability Act (HIPAA) 5010 COB Testing

Since September 27, 2010, the COBC has been testing HIPAA 837 pre-Errata version 5010 COB claims (that is, version 005010X223A1 for 837 institutional claims; and version 005010X222 for 837 professional claims) with various COBA trading partners.

The CMS will make HIPAA 837 Errata version 5010 claims (that is, version 005010X223A2 for 837 institutional claims; and version 005010X222A1 for 837 professional claims) available for testing with COBA trading partners as of April 4, 2011.  The CMS will only be able to move COBA trading partners into production on the HIPAA 5010 format after they have tested with the COBC using the Errata version of the HIPAA 5010 837 institutional and professional COB claims.