How to Appeal CO-173 Denial: Coverage/program guidelines not met
The service was denied because coverage or program guidelines were not met or were exceeded. This guide explains what it means, why it happens, and exactly how to build a winning appeal.
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What Does CO-173 Mean?
The service was denied because coverage or program guidelines were not met or were exceeded.
Commonly seen in:
Step-by-Step Appeal Guide for CO-173
- 1
Request the specific clinical criteria or LCD/NCD the payer used to deny the claim
- 2
Obtain all relevant clinical documentation: progress notes, lab results, imaging, referrals
- 3
Have the treating provider write a letter of medical necessity addressing the denial criteria
- 4
Cite applicable LCDs, NCDs, and peer-reviewed literature supporting the treatment
- 5
Submit the appeal with all documentation and request a peer-to-peer review if available
Counter-Arguments to Use in Your Appeal
These are the strongest arguments medical billing professionals use to overturn CO-173 denials.
Request the specific coverage policy or guideline used for the denial
Review whether the patient meets all coverage criteria
Provide clinical documentation addressing each specific coverage criterion
Request external review for medical necessity determinations
Regulations and Guidelines to Cite
Citing specific regulations strengthens your appeal and demonstrates you know your rights.
Expert Tip for CO-173 Appeals
Ask for the specific guideline number and version date. Payers must use up-to-date clinical guidelines — outdated criteria are challengeable.
Frequently Asked Questions
What is a CO-173 denial code?
The service was denied because coverage or program guidelines were not met or were exceeded.
Can I appeal a CO-173 denial?
Yes. All insurance denials are appealable. Follow the step-by-step guide above and submit your appeal before the payer's deadline, typically 180 days from the denial date.
What documentation do I need to appeal CO-173?
For a CO-173 denial, you typically need: the original denial letter/EOB, clinical documentation supporting the service, any prior authorization records, and a cover letter citing the relevant regulations listed above. The specific documents depend on why the denial was issued.
How long does a CO-173 appeal take?
Most payers are required to process standard appeals within 30–60 days. Expedited appeals (for urgent care) must be decided within 72 hours. Under ERISA, group health plans must provide an appeal decision within 60 days for pre-service and 60 days for post-service claims.
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