• This page, MassHealth Coordination of Benefits (COB), is offered by
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MassHealth Coordination of Benefits (COB)

Information about billing MassHealth after other insurance

Coordination of Benefits

Coordination of Benefits (COB) refers to the activities involved in determining MassHealth benefits when a member has other health insurance including Medicare, Medicare Advantage, or commercial insurance in addition to MassHealth that is liable to pay for health care services.


Related Regulations

MassHealth regulations at 130 CMR 450.316 require providers to make diligent efforts to identify and obtain payment first from other resources including casualty payer payments to ensure that the MassHealth agency is always the payer of last resort.

Providers should refer to the following MassHealth/Third Party Liability (TPL) regulations and billing guides located in their provider manual when submitting COB claims to MassHealth:

  • MassHealth Administrative and Billing Regulations at 130 CMR 450.316 through 450.318 and
  • Subchapter 5: Administrative and Billing Instructions, Part 7. Other Insurance.

You can find links to these below in "Additional Resources."

Additional Resources for

Job aids for COB claims submissions

You can find job aids for COB claims submissions at the Provider Online Service Center (POSC) . See "Additional Resources" below.

Providers must submit all claims electronically unless they have been approved for an electronic claim submission waiver. 

Additional Resources for

Related Bulletins

You can find additional information in the following All-Provider Bulletins:

  • All Provider Bulletin 273: MassHealth Coordination of Benefits (COB) Billing Best Practices and New Claim Error Codes
  • All Provider Bulletin 246: MassHealth Claims Involving Casualty Payer Payments
  • All Provider Bulletin 217: Waiver Policy for Claim Submissions 

See "Additional Resources" below. 



Additional Resources for

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