How do I resolve a CO-50 denial?

Obtain and review the payer's denial reason in detail — request the specific LCD/NCD or coverage policy cited. Pull the complete medical record for the date of service and surrounding encounters. Have the treating provider write a letter of medical necessity explaining the clinical rationale. Request a peer-to-peer review with the payer's medical director — this is the most effective first step for medical necessity denials. If peer-to-peer fails, file a formal written appeal citing the relevant clinical guidelines (ADA, AMA, SAMHSA) and payer's own policy. If internal appeal is denied, pursue external independent review if the payer is subject to ACA external review requirements.

Can I appeal a CO-50 denial?

Yes. CO-50 denials are typically appealable with a 58% success rate. Resolution difficulty is Hard and typically takes 21-60 days.

835 Denial Combination

CO-50

Contractual Obligation · Service-Line Level Adjustment

What This Combination Means

Medical necessity denial — the payer determined the service is not medically necessary based on their coverage policies, LCDs (Local Coverage Determinations), or NCDs (National Coverage Determinations). This is one of the most commonly appealed denials, with moderate success rates when strong clinical documentation is provided.

58%

Appeal Success

21-60 days

Avg. Resolution

Hard

Difficulty

Yes

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-50 combination — not generic advice.

1
Obtain and review the payer's denial reason in detail — request the specific LCD/NCD or coverage policy cited.
2
Pull the complete medical record for the date of service and surrounding encounters.
3
Have the treating provider write a letter of medical necessity explaining the clinical rationale.
4
Request a peer-to-peer review with the payer's medical director — this is the most effective first step for medical necessity denials.
5
If peer-to-peer fails, file a formal written appeal citing the relevant clinical guidelines (ADA, AMA, SAMHSA) and payer's own policy.
6
If internal appeal is denied, pursue external independent review if the payer is subject to ACA external review requirements.

Specialty Context

How CO-50 typically presents across different practice types.

Dental

Dental medical necessity denials are common for procedures like full-mouth X-rays, crown placement, or implants. The appeal must include narrative justification: why alternatives were inadequate, what clinical findings support the chosen treatment.

Medical

Appeal with the treating physician's clinical notes, the relevant LCD/NCD policy, and a letter of medical necessity from the ordering provider. Peer-to-peer review is highly effective for medical necessity denials.

Behavioral Health

Behavioral health medical necessity denials often target level of care (e.g., intensive outpatient vs. standard outpatient). Appeal with the clinician's assessment, treatment plan, and documentation of why a lower level of care is not clinically appropriate.

Individual Code References

View the standalone definition for each code in this combination.

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