Skip to main content
Call
CARC B9 · CO-B9

CARC B9 Denial: Patient is enrolled in a Hospice — How to Fix and Appeal

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Updated

TL;DR

CARC B9 (X12 Patient is enrolled in a Hospice). CARC B9 means the patient was enrolled in a hospice election period on the DOS.

Official X12 description

“Patient is enrolled in a Hospice.”

Source: X12 Claim Adjustment Reason Codes. The X12 External Code Lists are the single authoritative source for every CARC descriptor — always verify against the current release before building a claim-scrub rule.

What CARC B9 actually means

CARC B9 means the patient was enrolled in a hospice election period on the DOS. Medicare (and most commercial payers with a hospice benefit) require that all services related to the terminal illness flow through the hospice provider's per-diem rate. Services unrelated to the terminal illness can still be billed to Medicare Part A/B with the GW modifier (services not related to hospice) or GV (attending physician services for a hospice patient). Mis-categorizing a service as related vs. unrelated is the most common error here.

Common root causes

  • Service related to the terminal illness was billed outside the hospice (it should be included in the hospice per-diem).
  • Unrelated service was billed without the GW or GV modifier and hit the hospice edit.
  • Hospice election was not disclosed at registration and the provider did not know.

Prevention checklist

  • Check HETS (Medicare eligibility) for active hospice periods at every encounter for Medicare patients.
  • Train providers and coders on the GW/GV modifier use cases.
  • Ask patients about hospice enrollment at registration — many will not volunteer it.

Appeal strategy — step by step

Most CARC B9 denials clear faster with the right remediation than with a formal appeal. Work the steps in order and escalate only when a lower-effort path has been ruled out.

  1. 1If the service is unrelated to the terminal illness, rebill with modifier GW (or GV for attending physician services) and documentation supporting the unrelated diagnosis.
  2. 2If the service was related but provided by an out-of-hospice provider under agreement, coordinate with the hospice for payment from the per-diem rather than appealing CMS.
  3. 3For commercial-payer hospice denials, review the plan's hospice benefit language — commercial hospice rules differ from Medicare's.
Sample appeal-letter language for CARC B9
[Provider letterhead] Re: Appeal of CARC B9 — Claim #{claim_number} Member: {member_name} · Member ID: {member_id} Date(s) of Service: {dos} On {remittance_date} this claim was adjusted with CARC B9: "Patient is enrolled in a Hospice." We respectfully request reconsideration. The X12 External Code List definition of CARC B9 does not apply to this claim for the following reasons: 1. [Cite the clinical / coding / policy fact that rebuts the adjustment] 2. [Cite the supporting documentation attached — op note, EOB, LCD/NCD citation, NCCI edit indicator, modifier rationale] 3. [Cite the payer's own policy where applicable] Attached: {list supporting documents} Please process payment under the member's benefits. If additional information is required, contact the billing office at {provider_phone} or {provider_email}. Sincerely, {billing_manager_name}, {credentials}

Edit the bracketed fields before sending. This template is a starting point; a payer-specific appeal form may still be required — check the provider portal first.

Payer-specific notes

Payer-specific behavior for CARC B9 publishes here as the QuickIntell anonymized denial ETL ingests sufficient volume. In the meantime, consult the payer directory for the relevant provider manual and appeal form.

How common is CARC B9?

Search demand rank
#53

Out of 306 seeded CARCs, ranked by combined US monthly search volume for "CARC B9", "CO-B9 denial", and "denial code B9".

Platform frequency
Pending ETL

Platform frequency ranks publish once the anonymized denial-rate pipeline reaches the publication threshold (strategy §12 Phase 2).

How QuickRCM prevents CARC B9

QuickRCM catches the root causes above before the 837 leaves the clearinghouse:

  • Claim-scrub rules fire on every root cause listed above — the scrub references the same X12 CAS segment logic that drives the denial, so what the payer checks, QuickRCM checks first.
  • When a denial lands, QuickRCM routes it to the correct worker with the documentation bundle already attached (op note, LCD citation, modifier rationale, EOB, primary 835).
  • Appeal templates tuned to each CARC (including this one) pull the supporting facts from the claim and fill the bracketed fields automatically.
See QuickRCM →Book a demo

Frequently asked questions — CARC B9

What does CARC B9 mean?

CARC B9 is an X12 Claim Adjustment Reason Code. The official definition is: "Patient is enrolled in a Hospice." In plain English, the payer is telling you cARC B9 means the patient was enrolled in a hospice election period on the DOS. Medicare (and most commercial payers with a hospice benefit) require that all services related to the terminal illness flow through the hospice provider's per-diem rate. Services unrelated to the terminal illness can still be billed to Medicare Part A/B with the GW modifier (services not related to hospice) or GV (attending physician services for a hospice patient). Mis-categorizing a service as related vs. unrelated is the most common error here.

How do I resolve a CARC B9 (CO-B9) denial?

Start with the most common root cause: Service related to the terminal illness was billed outside the hospice (it should be included in the hospice per-diem). First step: If the service is unrelated to the terminal illness, rebill with modifier GW (or GV for attending physician services) and documentation supporting the unrelated diagnosis. See the full remediation and appeal checklist on this page before filing a formal appeal.

Is CARC B9 patient responsibility?

No — CARC B9 is typically carried under CO (Contractual Obligation) or OA (Other Adjustment), which means it is the provider's responsibility, not the patient's. Do not bill the patient unless the 835 CAS group code is PR.

What does CARC B9 look like on an EOB or 835 remittance?

On the 835 ERA, CARC B9 appears in Loop 2110 CAS segment as "CAS*CO*B9*{amount}". On a paper EOB the same code prints in the Adjustment/Denial Reason column with the X12 description: "Patient is enrolled in a Hospice." — usually paired with one or more RARC remark codes in the same remittance line for additional context.

Can CARC B9 be appealed successfully?

Yes — when the root cause does not apply to the specific claim. Overturn rates are strongest when the appeal cites the X12 definition, the payer's own published policy, and documentation that rebuts the payer's rationale. The sample appeal language block above is a starting point; always adapt it to the payer's reconsideration form.

Disclaimer

This page is operational reference for medical-billing professionals. It is not legal, clinical, or contractual advice. X12 code descriptors are maintained by the X12 External Code Lists; always verify against the current X12 release and the payer's own published policy before submitting or appealing a claim.