CARC 236 appeal letter template — Incompatible Procedure/Modifier Combination

CARC 236 means the payer determined that the billed procedure, or the procedure with the specific modifier applied, cannot be reported together with another procedure billed on the same claim (often an edit-based bundling or mutually-exclusive code conflict). This template helps staff dispute the denial when documentation supports separate, distinct, or appropriately modified services.

When to appeal vs. correct & resubmit

Appeal when the services billed were clinically distinct, performed at different sites, sessions, or with documented medical necessity justifying separate reporting, and you believe the modifier (e.g., 59, XE, XS, XP, XU) or coding combination was correctly applied and supported by records. Correct and resubmit instead if review confirms the codes were truly bundled, the modifier was missing or used incorrectly, or the procedures should not have been billed separately per correct coding guidelines.

Appeal letter template

Copy the template, replace every [bracketed] field with your details, and keep only the paragraph that fits your situation.

[Date]

[Payer Name]
Attn: Appeals Department
[Payer Address]

Re: Appeal of Claim Denial — CARC 236 (Incompatible Procedure/Modifier Combination)
Patient Name: [Patient Name]
Member ID: [Member ID]
Claim #: [Claim #]
Date(s) of Service: [DOS]
Provider: [Provider Name, NPI]
CPT/HCPCS Code(s) at Issue: [CPT/HCPCS]

Dear Appeals Reviewer,

This letter appeals the denial of the above claim under CARC 236, which indicates that the billed procedure or procedure/modifier combination was found incompatible with another procedure reported on the same claim.

We have reviewed the services provided on [DOS] and believe they were distinct, separately identifiable, and appropriately coded. Specifically, [explain why the procedures were separate — e.g., different anatomic site, different session, different diagnosis, or medical necessity for reporting both]. The modifier(s) applied to [CPT/HCPCS] were intended to reflect this distinction, and supporting documentation is enclosed for review.

We ask that the claim be reprocessed based on the enclosed medical records, which demonstrate that the procedures billed do not represent a duplicate, bundled, or otherwise incompatible combination of services under correct coding guidelines.

If additional clinical documentation, an itemized operative note, or clarification of the modifier usage would assist in this review, please contact our office at [Phone] or [Email]. We appreciate your timely reconsideration of this claim.

Sincerely,
[Provider Name, NPI]
[Practice Name]
[Phone]
[Email]

What to attach

• Original EOB/ERA showing the CARC 236 denial
• Complete medical records/operative or procedure notes for the date(s) of service
• Documentation supporting medical necessity for each billed procedure
• Coding rationale or modifier justification notes
• Corrected claim form if resubmission with modifier correction is also being considered

Frequently asked questions

More free billing tools: all appeal letters · denial codes · NCCI edits · Medicare fees

This template is for informational purposes only and does not constitute legal, billing, or coding advice. It is a general framework to be customized with accurate, verified information. Appeal outcomes are not guaranteed, and payer policies vary — consult your organization's compliance or billing experts before submission.