CARC 152 appeal letter template — Length of Service Not Supported
CARC 152 means the payer determined that the documentation submitted does not justify the duration/units of service billed; an appeal should supply clinical documentation supporting the length of service rendered.
When to appeal vs. correct & resubmit
Appeal when the medical record clearly documents the time, units, or duration of service billed and you believe the payer's review was incomplete or the documentation was overlooked or insufficient on initial submission. If the documentation genuinely does not support the length of service billed (e.g., a coding or charting error), correct the claim — adjust units/time and resubmit — rather than appealing.
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] Appeals Department [Payer Address] Re: Appeal of Denial — CARC 152 (Length of Service Not Supported) Patient Name: [Patient Name] Member ID: [Member ID] Claim #: [Claim #] Date(s) of Service: [DOS] Provider: [Provider Name, NPI] CPT/HCPCS Code(s): [CPT/HCPCS] Dear Appeals Reviewer, This letter is submitted to formally appeal the denial of the above-referenced claim under CARC 152, which indicates that the information submitted does not support the length of service billed. We respectfully disagree with this determination and request reconsideration based on the enclosed documentation. The attached medical records, including [progress notes/time-based documentation/flowsheets], substantiate the duration and medical necessity of the service(s) provided on [DOS]. Specifically, the documentation reflects the start and stop times, total minutes/units, and clinical rationale supporting the length of service billed under [CPT/HCPCS]. We ask that the payer re-review the claim in light of this additional documentation and reverse the denial associated with CARC 152. If any further information or clarification is needed, please contact [Provider Name, NPI] at [Phone] or [Email]. Thank you for your prompt attention to this matter. We look forward to your reconsideration. Sincerely, [Provider Name, NPI] [Practice Name] [Phone] [Email]
What to attach
- Explanation of Benefits (EOB) / Electronic Remittance Advice (ERA)
- Complete medical records for the date(s) of service, including time/unit documentation
- Physician or clinician progress notes supporting duration of service
- Flowsheets or nursing/therapy logs showing start and stop times, if applicable
- Copy of the original claim form (CMS-1500 or UB-04)
- Any prior authorization documentation, if relevant to duration approved
Frequently asked questions
What does CARC 152 mean?
It means the payer reviewed the claim and determined that the submitted documentation does not support the length of service (e.g., units or time) billed for the procedure or service code.
What documentation helps most in a CARC 152 appeal?
Time-stamped clinical notes, flowsheets, or logs that clearly show the start/stop times or total duration of the service, along with clinical justification for that length of service.
Should I correct and resubmit instead of appealing?
If review of the chart shows the billed units/time were inaccurate, it is often more efficient to correct the claim and resubmit rather than appeal. Appeal only when the documentation supports the original billed length of service.
Is a successful appeal guaranteed?
No. Appeal outcomes depend on payer policies and individual claim review; submitting a well-documented appeal does not guarantee reversal of the denial.
More free billing tools: all appeal letters · denial codes · NCCI edits · Medicare fees
This template is provided for informational and administrative purposes only and does not constitute legal, medical, or billing advice. It is a general framework to be customized based on the specific claim and payer requirements. Use of this template does not guarantee that an appeal will be successful or that a denial will be overturned.
Run visits, billing, and appeals in one place
Join providers across the country delivering modern virtual care with CareNiva. Free to start, ready in minutes.
100% Satisfaction Guaranteed — try it risk-free