Denial Code CO-300

Resubmission to correct payer

Use this cover letter when resubmitting the claim to the correct primary payer after a routing or coordination-of-benefits denial. This is NOT an appeal with the denying payer.

[Your Practice Letterhead]
[Date]

[Correct Payer Name]
Claims Department
[Correct Payer Address]

Re: Claim Submission — Prior Payer Denial Code CO-300
Patient: [Patient Name]
Member ID: [Member ID]
Date of Service: [DOS]

To Whom It May Concern:

The attached claim was initially submitted to [Prior Payer Name], which returned denial code CO-300 (Claim received by the Medical Plan, but benefits not available under this plan. Claim has been forwarded to the patient's Behavioral Health Plan for further consideration), indicating your plan is the responsible payer for this service.

Attached documentation:
• Original claim (CMS-1500 or UB-04)
• Prior payer's EOB or 835 electronic remittance advice showing the CO-300 denial
• Member eligibility confirmation for the date of service

Please process this claim per your standard adjudication timeline.

Sincerely,
[Provider Name or Billing Manager]
[NPI / TIN]
[Contact Phone]

---
This is a resubmission to the correct payer, not an appeal with the denying payer. For Medicare Secondary Payer situations, ensure the MSP questionnaire on file is current. For coordination-of-benefits, verify primary-payer status via real-time 270/271 eligibility before resubmitting.

CO-300 FAQ