CO-B9 Denial Code: Patient Is Enrolled in Hospice
The CO-B9 denial code means the patient is enrolled in a hospice program, and the payer considers the billed service part of the hospice benefit - services related to the terminal illness are paid through the hospice, not fee-for-service Medicare or the standard plan. Services unrelated to the terminal condition remain billable, but the claim must say so with the right modifier.
Common Causes
- The service relates to the patient's terminal condition and belongs under the hospice's bundled payment
- The claim did not indicate the service was unrelated to the terminal illness (missing modifier GW under Medicare)
- An attending physician not employed by the hospice billed without modifier GV
- The practice did not know the patient had elected hospice, so the claim went out with no hospice context at all
How to Fix CO-B9
- Check the patient's hospice election dates through eligibility and compare to the date of service
- If the service was related to the terminal condition, direct billing to the hospice per your arrangement with them - it is inside the hospice benefit
- If the service was unrelated to the terminal illness, resubmit with modifier GW and documentation supporting that it is unrelated
- If billing as the patient's designated attending physician (not hospice-employed), use modifier GV
- Screen eligibility for hospice election on every Medicare patient so claims are coded correctly the first time
Frequently Asked Questions
CO-B9 means the patient is enrolled in hospice and the payer treats the billed service as part of the hospice benefit. Services related to the terminal illness are paid through the hospice; unrelated services need modifier GW (or GV for the attending physician) to pay separately under Medicare.
Append modifier GW to certify the service is unrelated to the terminal condition and ensure the diagnosis coding reflects the unrelated condition. The designated attending physician who is not hospice-employed bills with modifier GV for terminal-condition-related professional services.
Related Denial Codes
Related Resources
Claim adjustment reason codes and remittance advice remark codes are standardized code sets maintained by X12. The explanations on this page are written in our own words for educational purposes, based on public CMS and Medicare contractor documentation. Payer policies vary - always confirm handling with the specific payer's guidance and your contracts.