How do I resolve a CO-16+N285 denial?

Verify whether the procedure/service actually required prior authorization using the payer's online portal or PA lookup tool. If auth was obtained: locate the authorization number in your records and resubmit with the auth number in the appropriate field (Box 23 on CMS-1500 / Loop 2300 REF*G1). If auth was not obtained but was required: contact the payer's provider line to request retroactive authorization — explain clinical necessity. If auth was not required: prepare a written appeal citing the payer's own coverage policy page that exempts this service. Attach supporting documentation (referral letter, clinical notes, auth policy excerpt) to the appeal. Submit appeal within the payer's appeal deadline (usually 60–180 days from denial date).

Can I appeal a CO-16+N285 denial?

Yes. CO-16+N285 denials are typically appealable with a 72% success rate. Resolution difficulty is Medium and typically takes 14-30 days.

835 Denial Combination

CO-16+N285

Contractual Obligation · Claim-Level Adjustment

What This Combination Means

Claim denied because required authorization information is missing from the submission. N285 confirms: the prior authorization or referral number is absent. The service may or may not require auth — the next step is to verify whether auth was truly required, and if so, obtain it retroactively or appeal with documentation that no auth was needed.

72%

Appeal Success

14-30 days

Avg. Resolution

Medium

Difficulty

Yes

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-16+N285 combination — not generic advice.

1
Verify whether the procedure/service actually required prior authorization using the payer's online portal or PA lookup tool.
2
If auth was obtained: locate the authorization number in your records and resubmit with the auth number in the appropriate field (Box 23 on CMS-1500 / Loop 2300 REF*G1).
3
If auth was not obtained but was required: contact the payer's provider line to request retroactive authorization — explain clinical necessity.
4
If auth was not required: prepare a written appeal citing the payer's own coverage policy page that exempts this service.
5
Attach supporting documentation (referral letter, clinical notes, auth policy excerpt) to the appeal.
6
Submit appeal within the payer's appeal deadline (usually 60–180 days from denial date).

Specialty Context

How CO-16+N285 typically presents across different practice types.

Dental

Many dental payers (particularly for ortho, implants, oral surgery) require predetermination numbers. Confirm whether the procedure required auth and if a predetermination was submitted.

Medical

Check the payer's authorization requirements for the CPT code and place of service. If auth was obtained, locate the auth number and resubmit. If no auth was required, appeal with the payer's own coverage policy.

Behavioral Health

Auth requirements are strict in behavioral health. Confirm the auth covers the specific CPT code, number of units, and place of service. Session-level auth tracking is critical.

Individual Code References

View the standalone definition for each code in this combination.

CARC 16 RARC N285

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